Document ZJovJNqrzGMzoo7rxZXoZkaeL

ABDOO136249 TUfe THRESHOLD LIMIT VALUES and BIOLOGICAL EXPOSURE INDICES for 1986-1987 American Conference of Governmental Industrial Hygienists ABDOO136305 where Ljs in W cm*8 sr-1 nm-1 and t is the viewing duration (or pulse duration if the lamp is pulsed) limited to 1 ps to 10 s, and a is the angular substance of the source in radians. If the lamp is oblong, a refers to the longest dimension that can be viewed. For instance, at a viewing distance r - 100 cm from a tubular lamp of length I = 50 cm, the viewing angle is: a = 1/r = 50/100 = 0.5 rad (2) 2. To protect against retinal photochemical injury from chronic blue-light exposure the integrated spectral radiance of a light source weighted against the blue-light hazard function Bj (Table 18) should not exceed: 1400 2 L* t Bj AA < 100 J cm-2 sr' (t < 10* s) 400 (3a) 1400 2 L, B* AA < 10-2 sr1 (t > 10* s) (3b) 400 The weighted product of L, and B, is termed L (blue). For a source radiance L weighted against the blue-light hazard func tion (L [blue]) which exceeds 10 mW cm-8 sr1 in the blue spectral region, the permissible exposure duration t^ in seconds is simply: t^, = 100 J cm-2 sr'/L (blue) (4) The latter limits are greater than the maximum permissible exposure limits for 440 nm laser radiation (see Laser TLV) be cause of a 2-3 mm pupil is assumed rather than a 7 mm pupil for the Laser TLV. For a light source subtending an angle a less than 11 mrd (0.011 radian) the above limits are relaxed such that the spectral irradiance weighted against the bluelight hazard function B, should not exceed E (blue). 1400 2, Ei tBiAA<10mJ cm-2 (t < 10* s) 400' (5a) i400J 2$i B* AA < 1 pW cm2 (t > 10* s) 400 (5b) For a source where the blue light weighted irradiance E (blue) exceeds 1 pW cm-8 the maximum permissible exposure duration t^ in seconds is: =* 10 mJ cra*2/E (blue) (6) 3. Infrared radiation: To avoid possible delayed effects upon the lens of the eye (cataractogenesis), the infrared radiation (A = 770 nm) should be limited to 10 mW cm-8. For an infrared heat lamp or any near-infrared source where a strong visual 108 TABLE 18 Spectral Weighting Functions for Assessing Retinal Hazards from Broad-Band Optical Sources Wavelength (nm) Blue-Light Hazard-Function B, Burn Hazard Function R, 400 405 410 415 420 425 430 435 440 445 450 455 460 465 470 475 480 485 490 495 500-600 600-700 700-770 770-1400 0.10 0.20 0.40 0.80 0.90 0.95 0.98 1.0 1.0 0.97 0.94 0.90 0.80 0.70 0.62 0.55 0.45 0.40 0.22 0.16 10U*5o-iyw) 0.001 0.001 0.001 1.0 2.0 4.0 8.0 9.0 9.5 9.8 10.0 10.0 9.7 9.4 9.0 8.0 7.0 6.2 5.5 4.5 4.0 2.2 1.6 1.0 1.0 10[(7OO-iVSQ5). 0.2 stimulus is absent, the near infrared (770-1400 nm) radiance as viewed by the eye should be limited to: 1400 } j 4 AA < 0.6/a (7)* 770 for extended duration viewing conditions. This limit is based upon a 7 mm pupil diameter. 109 AIRBORNE UPPER SONIC AND ULTRASONIC ACOUSTIC RADIATION These Threshold Limit Values (TLVs) refer to sound pres sure levels that represent conditions under which it is believed that nearly all workers may be repeatedly exposed without adverse effect. The values listed in Table 19 should be used as guides in the control of noise exposure and, due to individual suscepti bility, should not be regarded as fine lines between safe and dangerous levels. The levels for the third-octave bands centered below 20 kHz are below those which cause subjective effects. Those levels for 1/3 octaves above 20 kHz are for prevention of possible hearing losses from subharmonics of these frequencies. TABLE 19 Permissible Ultrasound Exposure Levels Mid-Frequency of Third-Octave Band kHz One-Third Octave--Band Level in dB re 20 pPa 10 12.5 16 20 25 31.5 40 50 80 80 80 105 110 115 115 115 2. Magnetic Fields. Both pulsed and 'continuous. 3. Laser Radiation. Specifically laser exposures of less than one (1) nanosecond. 4. Vibration. Whole-body. 5. Pressure Variations. PHYSICAL AGENTS UNDER STUDY The Physical Agents TLV Committee of ACGIH has examined the current literature and has not found sufficient information to propose a TLV. However, these agents will remain under study during the coming year to examine new evidence indicating the need and feasibility for establishing a proposed TLV. Comments and suggestions, accompanied by substantive documentation are solicited and should be forwarded to the Executive Secretary, ACGIH. Documentation summarizing the current status of the biological effects literature is available on those agents preceded by an asterisk (*). 1. *Extremely Low Frequency (ELF) Radiation. Specifically, that portion of the spectrum from 0 to 300 Hz. 110 Ill frQDOQl-36307 vfhe American Conference of Governmental Industrial Hygienists l VI/as organized in 1938 by a group of governmental industrial hygienists who desired a medium for the free exchange of ideas, experiences and the promotion of standards and techniques in industrial health. The Conference is a professional society, not an official Government Agency. tt is an organization devoted to the development of administrative and technical aspects of worker health protection. The association has contributed substantially to the development and improvement of official industrial health sevices to industry and labor. The com mittees on Industrial Ventilation and Threshold Limit Values are recognized throughout the world for their expertise and contribu tions to industrial hygiena Membership is limited to professional personnel in governmental agencies or educational institutions engaged in occupational safety and health programs. The more than 3100 members from across the United States and around the world give the organization an international scope. ABDOO136308 ISBN: 0-936712-69-4 --ABiMO 136250 1986 by the American Conference of Governmental Industrial Hygienists. ISBN: 0-936712-69-4 TLVs New material or revisions for 1986-87: Chemical Substances: 1) Some 150 STELs deleted from those substances proposed in 1984, with the adopted TLV-TWAs retained. In place of these deleted STELs, the Excursion Limits section contained in the Introduction to the Chemical Substances Is to be used when short-term exposures are encountered, even when the 8-hour. TLV-TWA is within recommended limits; 2) All mppcf values have been deleted in favor of gravimetric measuring, as well as Appendix F, cover ing the conversion from mppcf to mass concentration; 3) Appendix G, Chem ical Substances and Issues Under Study, becomes Appendix F with the addition of a section on Particle Size-selective Sampling Criteria for Airborne Particulate Matter for review and comments. Biological Exposure Indices: 1) BEls for carbon monoxide, ethyl benzene, styrene, toluene, trichloro ethylene and xylenes are the first adopted BEls recommended by ACGIH; 2) Notice of Intent to Establish BEls for aniline, cadmium, carbon disulfide, dimethylformamide, methyl ethyl ketone and pentachlorophenol. Physical Agents: 1) Adoption of the Cold Stress, Hand-arm (Segmental) Vibration, and the Repetitively Pulsed Lasers TLVs; 2) Adoption of new footnote to Table 10 in the Laser section. Threshold Limit Values for Chemical Substances in the Work Environment Adopted by The limits listed in this book are intended for use in the practice of indus trial hygiene as guidelines or recommendations in the control of potential health hazards and for no other use. These limits are not fine lines between safe and dangerous concentration and should not be used by anyone un trained in the discipline of industrial hygiene. It is imperative that the user of this book read the Introduction to each section before applying the recom mendations contained herein as this is an integral part to the understand ing and use of this book. The ACGIH disclaims liability with respect to the use of the TLVs in a manner inconsistent with their intended use. ACGIH Interpretation of TLVs: All requests for interpretations of TLVs must be in writing, in care of the Executive Secretary ACGIH. Interpretations will be made only after full committee review and approval. Interpretaitons will be published annually in the Annals of ACGIH, the volume which covers the annual meeting. Documentation of the Threshold Limit Values and Biological Exposure Indices: A separate companion piece to the TLVs/BEIs is issued by ACGIH under this title. This publication gives the pertinent scientific information and data with reference to literature sources that were used to base each limit or index. For better understanding of the TLVs and BEls, it is essential that the Documentation be consulted when the TLVs are being used or when invoking the BEls. For further information contact the Publications Office, ACGIH. Copyright: This book is fully protected by copyright and no part of it may be reproduced in any form, by print, photoprint, microfilm, or any other means without written permission from the American Conference of Govern mental Industrial Hygienists, in care of the Executive Secretary. Requests for interpretations, reproduction permission, information, and/or placement of an Older may use the following address: ACGIH, 6500 Glenway Ave., Bldg. D-7, Cincinnati, OH 45211-4438; 513/661-7881. with Intended Changes for 1986-87 1985-86 CHEMICAL SUBSTANCES TLV COMMITTEE ABDOD136251 TABLE OF CONTENTS Ernest Mastromatteo, M.D., University of Toronto--Chair James R. Crawl, CIH, US Navy D. Dwight Culver, M.D., University of Califomia-lrvine James W. Hammond, CIH, University of Texas Trent R. Lewis, Ph.D., NIOSH Jesse Lieberman, PE, US Navy Frederick T. McDermott, CIH-Deceased 1986 Waiter W. Melvin, Jr., M.D., Sc.D., Colorado State University Mary K. Murphy, OSHA Leonard D. Pagnotto, CIH, Retired Ronald S. Ratney, Ph.D., CIH, OSHA Meier Schneider, PE, CIH, Metropolitan Water District of Southern California Robert Spirtas, Dr. PH, National Cancer Institute Vera F. Thomas, Ph.D., University of Miami William D. Wagner, NIOSH Chemical Substances Introduction ....................................... Adopted Threshold Limit Values.................................................. Dusts................................................................................................. Notice of Intended Changes......................................................... Adopted Appendices A. Carcinogens................................................................................ B. Substances of Variable Composition.............................. C. Threshold Limit Values for Mixtures................................. D. Nusiance Particulates............................................................ E. Asphyxiants............................................................................... F. Chemical Substances Under Study................................. G. Registered Trade Names.................................................... 2 9 34 36 39 44 45 47 48 48 50 Biological Exposure Indices CONSULTANTS Gerald L. Kennedy, Jr., Ph.D. Georg Kimmerle, M.D., German MAK Commission Liaison William S. Lainhart, M.D. George Roush, Jr., M.D. Marshall Steinberg, Ph.D. Theodore R. Torkelson, Sc.D. Ralph C. Wands Elizabeth K. Weisburger, Ph.D. Mitchell R. Zavon, M.D. Introduction ......................................................................................... Adopted Indices.......................................... Notice of Intent to Establish......................................................... Chemical Substances Under Study to Establish BEIs____ 55 58 60 62 Physical Agents Introduction......................................................................................... Adopted Threshold Limit Values Heat Stress .................................................................................... Cold Stress....................................................................................... Hand-Arm (Segmental) Vibration............................................. Ionizing Radiation ........................................................................ Lasers................................................................................................. Noise Continuous.................................................................................. Impulsive or Impact................................................................. Radiofrequency/Microwave Radiation................................... Ultraviolet Radiation.......................................................l............. Notice of Intended Changes......................................................... Light and Near-Infrared Radiation........................................... Airborne Upper Sonic and Acoustic Radiation.................. Agents Under Study........................................................................ 65 66 73 83 88 88 98 99 100 104 107 107 110 110 1 ABD00} 36252 INTRODUCTION TO THE CHEMICAL SUBSTANCES Threshold limit values refer to airborne concentrations of sub stances and represent conditions under which it is believed that nearly all workers may be repeatedly exposed day after day without adverse effect. Because of wide variation in individual suscepti bility, however, a small percentage of workers may experience dis comfort from some substances at concentrations at or below the threshold limit; a smaller percentage may be affected more seriously by aggravation of a pre-existing condition or by develop ment of an occupational illness. Threshold limits are based on the best available information from industrial experience, from experimental human and animal studies, and, when possible, from a combination of the three. The basis on which the values are established may differ from sub stance to substance; protection against impairment of health may be a guiding factor for some, whereas reasonable freedom from irritation, narcosis, nuisance or other forms of stress may form the basis for others. The amount and nature of the information available for establishing a TLV varies from substance to substance; conse quently, the precision of the estimated TLV is also subject to vari ation and the latest Documentation should be consulted in order to assess the extent of the data available for a given substance. These limits are Intended for use In the practice of Indus trial hygiene as guidelines or recommendations In the control of potential health hazards and for no other use, e.g., in the evaluation or control of community air pollution nuisances, In estimating the toxic potential of continuous, uninterrupted ex posures or other extended work periods, as proof or disproof of an existing disease or physical condition, or adoption by countries whose working conditions differ from those In the United States of America and where substances and processes differ. These limits are not fine lines between safe and dan gerous concentration and should not be used by anyone un trained in the discipline of industrial hygiene. The Threshold Limit Values, as issued by ACGIH, are recom mendations and should be used as guidelines for good practices. In spite of the fact that serious injury is not believed likely as a result of exposure to the threshold limit concentrations, the best practice is to maintain concentrations of all atmospheric con taminants as low as is practical. The ACGIH disclaims liability with respect to the use of TLVs in a manner inconsistent with their Intended use as stated herein. Notice of Intent. At the beginning of each year, proposed actions of the Committee for the forthcoming year are issued in the form of a "Notice of Intended Changes." This Notice provides not only an opportunity for comment, but solicits suggestions of 2 substances to be added to the list. The suggestions should be ac companied by substantiating evidence. The listof Intended Changes follows the Adopted Values in the TLV booklet. Values listed in parenthesis in the "Adopted" list are to be used during the period in which a proposed change for that Value is listed in the Notice of intended Changes. Definitions. Three categories of Threshold Limit Values (TLVs) are specified herein, as follows: a) 7he Threshold Limit Value-77me Weighted Average (TLVI TWA)--the time-weighted average concentration for a normal 8-hour workday and a 40-hour workweek, to which nearly all workers may be repeatedly exposed, day after day, without adverse effect. b) Threshold Limit Value-Short Term Exposure Limit (TLVI STEL)--the concentration to which workers can be exposed corv i tinuously for a short period of time without suffering from 1) irrita tion, 2) chronic or irreversible tissue damage, or 3) narcosis of sufficient degree to increase the likelihood of accidental injury, im- . pair self-rescue or materially reduce work efficiency, and provided ' that the daily TLV-TWA is not exceeded. It is not a separate independent exposure limit, rather it supplements the time-weighted I average (TWA) limit where there are recognized acute effects from a substance whose toxic effects are primarily of a chronic nature. STELs are recommended only where toxic effects have been reported from high short-term exposures In either humans or animals. A STEL is defined as a 15-minute time-weighted average exposure which should not be exceeded at any time during a work day even if the eight-hour time-weighted average is within the TLV. Exposures at the STEL should not be longer than 15 minutes and should not be repeated more than four times per day. There should be at least 60 minutes between successive exposures at the STEL. An averaging period other than 15 minutes may be recommended when this is warranted by observed biological effects. c) Threshold Limit Value-Ceiling (TLV-C)--the concentration that should not be exceeded during any part of the working exposure. In conventional industrial hygiene practice if instantaneous monitoring is not feasible, then the TLV-C can be assessed by sam pling over a 15-minute period except for those substances which may cause immediate irritation with exceedingly short exposures. For some substances, e.g., irritant gases, only one category, the TLV-Ceiling, may be relevant. For other substances, either two or three categories may be relevant, depending upon their phys iologic action. It is important to observe that if any one of these three TLVs is exceeded, a potential hazard from that substance is presumed to exist. The Committee holds to the opinion that limits based on physical irritation should be considered no less binding than those based on physical impairment. There is increasing evidence that 3 ABDOQ 136253 should be. The approach here is that the maximum recommended physical irritation may initiate, promote or accelerate physical im pairment through interaction with other chemical or biologic agents. Time-Weighted Average vs Celling Limits. Time-weighted averages permit excursions above the limit provided they are com pensated by equivalent excursions below the limit during the work day. In some instances it may be permissible to calculate the average concentration for a workweek rather than for a workday. The relationship between threshold limit and permissible excur sion is a rule of thumb and in certain cases may not apply. The amount by which threshold limits may be exceeded for short periods without injury to health depends upon a number of factors such as the nature of the contaminant, whether very high concentrations--even for short periods--produce acute poison ing, whether the effects are cumulative, the frequency with which high concentrations occur, and the duration of such periods. All factors must be taken into consideration in arriving at a decision as to whether a hazardous condition exists. Although the time-weighted average concentration provides the most satisfactory, practical way of monitoring airborne agents for compliance with the limits, there are certain substances for which it is inappropriate. In the latter group are substances which are predominantly fast acting and whose threshold limit is more appropriately based on this particular response. Sustances with excursion should be related to variability generally observed in actual industrial processes. Leidel, Busch and Crouse,* in review ing large numbers of industrial hygiene surveys conducted by NIOSH, found that short-term exposure measurements were gener ally log normally distributed with geometric standard deviation mostly in the range of 1.5 to 2.0. While a complete discussion of the theory and properties of the log normal distribution is beyond the scope of this section, a brief description of some important terms is presented. The meas ure of central tendency in a log normal description is the antilog of the mean logarithm of the sample values. The distribution is skewed and the geometric mean is always smaller than the arith metic mean by an amount which depends on the geometric stan dard deviation. In the log normal distribution, the geometric standard deviation (sd^) is the antilog of the standard deviation of the sample value loganthms and 68.26% of all values lie between mg/sdg and mg x sdg. If the short-term exposure values in a given situation have a geometric standard deviation of 2.0,5% of all values exceed 3.13 times the geometric mean. If a process displays a variability greater than this, it is not under good control and efforts should be made to restore control. This concept is the basis for the new excursion limit recommendations which are as follows: this type of response are best controlled by a ceiling "C" limit that Short-term exposures should exceed three times the TLV-TWA should not be exceeded. It is implicit in these definitions that the for no more than a total of 30 minutes during a work day and manner of sampling to determine noncompliance with the limits for each group must differ; a single brief sample, that is applicable to a "C" limit, is not appropriate to the time-weighted limit; here, a sufficient number of samples are needed to permit a timeweighted average concentration throughout a complete cycle of operations or throughout the work shift. Whereas the ceiling limit places a definite boundary which con centrations should not be permitted to exceed, the time-weighted average limit requires an explicit limit to the excursions that are permissible above the listed values, it should be noted that the same factors are used by the Committee in determining the magnitude of the value of the STELs, or whether to Include or exclude a substance for a "C" listing. Excursion Limits. For the vast majority of substances with a TLV-TWA, there is not enough toxicological data available to warrant a STEL Nevertheless, excursions above the TLV-TWA should be controlled even where the eight-hour TWA is within recommended limits. Earlier editions of the TLV list included such limits whose values depended on the TLV-TWAs of the substance in question. While no rigorous rationale was provided for these particular underno circumstances should they exceed five times the TLVTWA, provided that the TLV-TWA is not exceeded. The approach is a considerable simplification of the idea of the log normal concentration distribution but is considered more convenient to use by the practicing industrial hygienist. If exposure excursions are maintained within the recommended limits, the geometric standard deviation of the concentration measurements will be near 2.0 and the goal of the recommendations will be accomplished. When the toxicological data for a specific substance are avail able to establish a STEL, this value takes precedence over the excursion limit regardless of whether it is more or less stringent. "Skin" Notation. Listed substances followed by the desig nation "Skin" refer to the potential contribution to the overall ex posure by the cutaneous route including mucous membranes and eye, either by airborne, or more particularly, by direct contact with the substance. Vehicles can alter skin absorption. Little quantitative data are available describing absorption of vapors and gases through the skin. The rate of absorption is a func tion of the concentration to which the skin is exposed. values, the basic concept was intuitive: in a well controlled process exposure, excursions should be held within some reasonable limits. Unfortunately, neither toxicology nor collective industrial hygiene * Leidel, NA. KA Busch and W.. Crouse: Exposure Measurement, Action Level and Occupational Environmental Variability. NIOSH Pub. No. 76-131 (December 1975). experience provide a solid basis for quantifying what those limits 5 4 ABDOQ136254 Substances having a skin notation and a low TLV may present a problem at high airborne concentrations, particularly if a signifi cant area of the skin is exposed for a long period of time. Protec tion of the respiratory tract, while the rest of the body surface is exposed to a high concentration, may present such a situation. Biological monitoring should be considered to determine the relative contribution of dermal exposure to the total dose. This attention-calling designation is intended to suggest appro priate measures for the prevention of cutaneous absorption so that the threshold limit is not invalidated. M/xtures. Special consideration should be given also to the application of the TLVs in assessing the health hazards which may be associated with exposure to mixtures of two or more substances. A brief discussion of basic considerations involved in developing threshold limit values for mixtures, and methods for their develop ment, amplified by specific examples, are given in Appendix C. Nuisance Particulates. In contrast to fibrogenic dusts which cause scar tissue to be formed in lungs when inhaled in exces sive amounts, so-called "nuisance" dusts have a long history of little adverse effect on lungs and do not produce significant organic disease or toxic effect when exposures are kept under reasonable control. The nuisance dusts have also been called (biologically) "inert" dusts, but the latter term is inappropriate to the extent that there is no dust which does not evoke some cellular response in the lung when inhaled in sufficient amount. However, the lungtissue reaction caused by inhalation of nuisance dusts has the following characteristics: 1) the architecture of the air spaces re mains intact; 2) collagen (scar tissue) is not formed to a signifi cant extent; and 3) the tissue reaction is potentially reversible. Excessive concentrations of nuisance dusts in the workroom air may seriously reduce visibility, may cause unpleasant deposits in the eyes, ears and nasal passages (Portland cement dust), or cause injury to the skin or mucous membranes by chemical or mechanical action per se or by the rigorous skin cleansing proce dures necessary for their removal. A threshold limit of 10 mg/m3 of total dust <1% quartz is recommended for substances in these categories and for which no specific threshold limits have been assigned. This limit, for a normal workday, does not apply to brief exposures at higher con centrations. Neither does it apply to those substances which may cause physiologic impairment at lower concentrations but for which a threshold limit has not yet been adopted. Some nuisance par ticulates are given in Appendix D. This list is not meant to be ail inclusive; the substances serve only as examples. Simple Asphyxiants-- 'Inert" Gases or Vapors. A number of gases and vapors, when present in high concentrations in air, act primarily as simple asphyxiants without other significant phys iologic effects. A TLV may not be recommended for each simple asphyxiant because the limiting factor is the available oxygen. The minimal oxygen content should be 18 percent by volume under normal atmospheric pressure (equivalent to a partial pressure, p02 of 135 mm Hg). Atmospheres deficient in 02 do not provide adequate warning and most simple asphyxiants are odorfess. Several simple asphyxiants present an explosion hazard. Account should be taken of this factor in limiting the concentration of the asphyxiant. Specific examples are listed in Appendix E. This list is not meant to be all inclusive; the substances serve only as examples. Physical Factors. It is recognized that such physical factors as heat, ultraviolet and ionizing radiation, humidity, abnormal pres sure (altitude), and the like may place added stress on the body so that the effects from exposure at a threshold limit may be altered. Most of these stresses act adversely to increase the toxic response of a substance. Although most threshold limits have built-in safety factors to guard against adverse effects to moderate deviations from normal environments, the safety factors of most substances are not of such a magnitude as to take care of gross deviations. For example, continuous work at temperatures above 90F, or over time extending the workweek more than 25%, might be considered gross deviations. In such instances judgment must be exercised in the proper adjustments of the Threshold Limit Values. Hypersusceptibility. Tests are available (J. Occup. Med. 15:564,1973; Ann. N.Y. Acad. Scl. 151, Art. 2:968,1968) that may be used to detect those individuals hypersusceptible to a variety of industrial chemicals (respiratory irritants, hemolytic chemicals, organic isocyanates, carbon disulfide). Unlisted Substances. Many substances present or handled in industrial processes do not appear on the TLV list. In a number of instances the material is rarely present as a particulate, vapor or other airborne contaminant, and a TLV is not necessary. In other cases sufficient information to warrant development of a TLV, even on a tentative basis, is not available to the Committee. Other sub stances, of low toxicity, could be included in Appendix D pertain ing to nuisance particulates. This list (as well as Appendix E) is not meant to be all inclusive: the substances serve only as examples. In addition there are some substances of not inconsiderable toxicity, which have been omitted primarily because only a limited number of workers (e.g., employees of a single plant) are known to have potential exposure to possibly harmful concentrations. Trade names. Because many chemical substances are mar keted under several trade names, the trade names have been replaced with their generic equivalent in the alphabetical listing. Appendix G was created to ease this transition and the CAS number appears with the generic name to aid identification. Operational Guidelines. The ACGIH Board of Directors has adopted operational guidelines for Chemical Substances TLV Com mittee. These guidelines prescribe: charge, authority, policies, 6 7 ABDOOL36255 membership, organization, and operating procedures. The policies inciude the appeals procedures. Copies of the guidelines docu ment are available from the Publications Office at a cost of $5 per copy. NOTE: In the interest of keeping this book as small as possible, the footnotes for the adopted values appear on right hand pages only. Substance [CAS #] ADOPTED VALUES TWA STEL ppm" mg/m3" ppm" mg/m3" Acetaldehyde [75-07-0]... 100 180 Acetic acid (64-19-7]......... 10 25 Acetic anhydride [108-24-7] C5 C 20 Acetone [67-64-1]............. 750 1,780 Acetonitrile [75-05-8]--Skin 40 70 Acetylene [74-86-2]........... E -- Acetylene dichloride, see 1,2-Dichloroethylene `Acetylene tetrabromide [79-27-6] ....................... 1 15 Acetyisallcylic acid (Aspirin) [50-78-2] ....................... -- 5 Acrolein [107-02-8].......... tAcrylamide [79-06-1]--Skin 0.1 -- 0.25 (0-3) Acrylic acid [79-10-7]___ 10 30 Acrylonitrile [107-13-1] -- Skin................................ 2,A2 4.5.A2 *Aldrin 1309-00-2] - Skin . -- 0.25 Ally! alcohol [107-18-6] -- Skin................................ 2 5 Ally! chloride [107-5-1] ... 1 3 Ally! glyddyl ether (AGE) [106-92-3]--Skin........... 5 22 Allyl propyl disulfide [2179-59-1] ................... VAIumina [1344-28-1] ... 2 -- 12 D Aluminum [7429-90-5] * Metal & oxide............... -- 10 Pyro powders................. -- 5 Welding fumes............... -- 5 Soluble salts................... _ 2 Alkyls (NOCf)................. -- 2 4-AminodiphenyJ [92-67-1]--Skin............. - Alb 2-Aminoethanol, see Ethanolamine `2-Aminopyridine [504-29-0] 0.5 2 3-Amino 1,2,4-triazole, see Amitrole `Amitrole [61-82-5]............. -- 0.2 Ammonia [7664-41-7]___ 25 18 150 15 -- 1,000 60 -- -- 0.3 -- -- ___ -- 4 2 10 3 -- _ ___ -- -- -- -- __ 35 270 37 -- 2,375 105 -- -- 0.8 (0.6) ___ -- 10 6 44 18 -- ___ ___ _ _ -- -- -- _ 27 (a) Parts of vapor or gas per million pans of contaminated air by volume at 25C and 760 ton. (b) Approximate milligrams of substance per cubic meter of air. t See Notice of Intended Changes. * 1986-67 Addition. Capital letters A, B, D & E refer to Appendices; C denotes ceiling limit. 9 8 ABDOO136256 Substance [CAS #1 ADOPTED VALUES TWA ppm" 5 E E STEL ppm" mg/m*" Ammonium chloride fume [12125-02-9]..................... 'Ammonium suifamate (7773-06-0) ................... {n-Amyl acetate [628-63-7] {sec-Amyl acetate [626-38-0] 'Aniline [62-53-3] & homologues--Skin .... Anisidine [29191-524] (o-, p- isomers)--Skin............. Antimony [7440-36-0] & compounds, as Sb .... Antimony trioxide [1309-644] Handling and use, as Sb Production..................... *ANTU [86-884]................. Argon [7440-37-1]............. Arsenic [7440-38-2] & soluble compounds, as As.............................. Arsenic trioxide production [1327-53-3] ................... Arsine [778442-1]............. Asbestos [1332-214], see DUSTS ............................ {Asphalt (petroleum) fumes [8052424] ................... Atrazine [1912-24-9]......... 'Azinphos-methyl [86-50-0]-Skin............. Barium [7440-39-3], soluble compounds, as Ba......... 'Benomyl [17804-35-2].... {Benzene [7143-2]............. Benzidine [92-87-5]--Skin p-Benzoquinone, seeQuinone Benzoyl peroxide [94-36-0] Benzo(a)pyrene [50-32-8] . Benzyl chloride [10044-7] Beryllium [744041-7] & compounds, as Be___ {Biphenyl [92-524]............. 'Bismuth telluride [1304-82-1] * Se-doped....................... 10 _ 10 100 530 (150) 125 665 (150) _2 10 _0.1 0.5 _ _0.5 0.5 -- A2 -- -- 0.3 -- E ---- 0.2 0.05 A2 0.2 -- Ala _ 5_ -- 5-- _0.2 0.8 10,A2 -- 0.5 10 30,A2 Alb -- (25,A2) -- _ 5_ -- A2 -- 1 5-- _ 0.002,A2 0.2 1.5 -- 10 --5 (0.6) -- -- 20 (800) (800) _ _ _ -- -- -- -- (10) -- -- (75,A2) -- -- -- (4) -- -- Substance [CAS #] ADOPTED VALUES TWA STEL ppm" mg/m3" ppm" mg/m*" Borates, tetra, sodium salts [1303-964] Anhydrous..................... Decahydrate................... -- -- 1 5 Pentahydrate ................. -- 1 'Boron oxide [1303-86-2].. -- 10 'Boron tribromide [10294-334] ................. C1 C 10 Boron trifluoride [7637-07-2] C1 C3 'Bromacil [31440-9]........... 1 10 Bromine [7726-95-6]......... 0.1 0.7 'Bromine pentafluoride [7789-30-2] ................... 0.1 0.7 Bromochloromethane, see Chlorobromomethane Bromoform [75-25-2]--SWn 0.5 5 '1,3-Butadiene [106-990].. 10.A2 22,A2 Butane [106-97-8]............. 800 1,900 Butanelhiol, see Butyl mercaptan 2-Butanone, see Methyl ethyl ketone (MEK) {2-Butoxyethanol [111-76-2]-Skin.......... 25 120 n-Butyt acetate [123-864], 150 710 {sec-Butyl acetate [105464] 200 950 {tert-Butyl acetate [54088-5] 200 950 Butyl acrylate [141-32-2].. 10 55 n-Butyl alcohol [71-36-3] -- Skin................................ C 50 C 150 sec-Butyl alcohol [78-92-2] 100 305 tert-Butyl alcohol [75-65-0] 100 300 Butylarrtne [10973-9]--SWn C5 C 15 tert-Butyl chromate, as CrOj [1189-85-1]--Skin........ -- C0.1 n-Butyl glycidyl ether (BGE) [2426-08-6] ................... 25 135 n-Butyl lactate [138-22-7]. 5 25 Butyl mercaptan [109795] o-sec-Butylphenol 0.5 1.5 [8972-5]-Skin............ 5 30 p-tert-Butyttoluene [9951-1] 10 60 'Cadmium [7440499] Dusts & salts, as Cd.............. 0.05 _ -- -- -- -- -- -- 0.3 -- __ -- (75) 200 (250) (250) -- 150 150 -- -- -- -- -- _ 20 -- __ -- -- -- -- -- -- 2 -- __ __ (360) 950 (1,190) (1,190) -- -- 455 450 -- -- -- _ -- _ 120 -- Capital letters A, B, D & E refer to Appendices; C denotes ceiling limit. * 1986-87 Addition. 10 11 i ABDOfrl 36-257 Substance [CAS tf] ADOPTED VALUES TWA STEL ppm" mg/m3*' ppm" mg/m14' Cadmium oxide {1306-19-0] Fume, as Cd................. Production..................... _-- C 0.05 0.05 -- _ -- _ 'Calcium carbonate/marble 11317-65-3] ................... -- D-- _ 'Calcium cyanamide [156-62-7] ..................... -- 0.5 -- -- Calcium hydroxide [1305-62-0] ................... -- 5-- -- Calcium oxide [1305-78-8] -- 2-- -- > Calcium silicate [1344-95-2] -- D-- -- ' Camphor, synthetic [76-22-2] 2 12 3 18 , {Caprolactam [105-60-2] : Dust................................ -- (D -- (3) Vapor .............................. (5) (20) (10) (40) > Captafol [2425-06-1]--Skin -- 0.1 -- -- 'Captan [133-06-2]............. -- 5-- -- 'Carbaryi [63-25-2]............. -- 5-- -- Caibofuran [1563-66-2]... -- 0.1 -- -- . 'Cartoon black [1333-864] . -- 3.5 -- -- j: 'Carbon dioxide 1124-38-9], 5,000 9,000 30,000 54,000 Carbon disulfide [75-15-0] -- ii; Skin................................ 10 30 __ -- ;i Carbon monoxide [630-084)] 50 55 400 440 | Carbon tetrabromide !, (558-134] ...................... 0.1 1.4 0.3 4 ! 'Carbon tetrachloride !' [56-23-5]-Skin............. 5,A2 30,A2 -- -- ,j Carbonyl chloride, see Phosgene Cartoonyi fluoride [353-50-4] 2 55 15 _!' i Catechol [120-80-9]........... 5 20 -- 'Cellulose (paper fiber) [9004-34-6] ................... -- D-- -- Cesium hydroxide IS [21351-79-1] ................. _ 2-- -- 1 Chlordane [57-74-9]--Skin -- 0.5 -- 2 Chlorinated camphene : [8001-35-2]-Skin......... -- 0.5 -- 1 1 Chlorinated diphenyl oxide _1 [55720-99-5] ................. -- 0.5 2 Chlorine [7782-50-5]......... 1 33 9 Chlorine dioxide (10046644] 0.1 0.3 0.3 0.9 Chlorine trifluoride [7790-91-2] ................... C 0.1 C 0.4 -- -- 12 Substance[CAS ____________ ADOPTED VALUES TWA STEL ppm*' mg/m3*' ppm" mg/m3*' ChloroacetaJdehyde [107-20-0] ..................... Ct C3 o-Chloroacetophenone [532-274] ..................... 0.05 0.3 Chtoroacety) chloride [79-04-9] ....................... 0.05 0.2 Chlorobenzene [108-90-7] . 75 350 o-Chlorobenzylidene malononitrile [269841-1]--Skin......... C 0.05 C 0.4 Chlorobromomethane [74-97-5] ........................ 200 1,050 2-Chloro-1,3-butadiene, see 0-Chloroprene Chlorodifiuoromethane [7545-61 ........................ Chlorodlpheny! 1,000 3,500 (42% Chlorine) [53469-21-9]-Skin.... Chlorodiphenyl 1 (54% Chlorine) [11097-69-1]--Skin___ 0.5 1-Chloro,2,3-epoxy-propane, see Epichlorohydrin 2-Chloroethanol, see Ethylene chlorohydrin Chloroethylene, see Vinyl chloride 'Chloroform [67-66-3]........ 10,A2 50,A2 bis(Chtoromethyl) ether [542-86-1] ..................... 0.001, 0.005. Chloromethyl methyl ether Ala Ala [107-30-2]...................... A2 A2 1-Chtoro-l -nitropropane (600-25-9] ..................... 2 10 Chloropentafluoroethane [76-15-3] ....................... Chloropicrin [76-062]___ (3-Chloroprene 1,000 0.1 6,320 0.7 [126-99-8]--Skin........... 10 35 o-Chlorostyrene [2039-874] ................... 50 285 o-Chlorotoluene [9549-8] ........................ 50 250 _ 250 1,250 0.3 75 75 _ _ 1,300 4,375 2 1 2 430 375 Capital letters A. B, D & E refer to Appendices; C denotes ceiling limit t See Notice of Intended Changes. * 1986*1987 Addition. 13 ABDOOi 36258 Substance [CAS#] ADOPTED VALUES TWA STEL ppm" mg/m3" ppm" mg/m3" 2-Chloro-6-(trichloromethyi) pyridine, see Nitrapyrin Chlorpyrifos [2921-68-2)- Skin................................ -- 00..22 Chromite ore processing (Chromate), as Cr......... - 0.05,Ala Chromium [7440-47-3] Metal.............................. - 0.5 Chromium compounds, as Cr . 0.5 Chromium (III) compounds, as Cr.............................. 0.5 Chromium (Vi) compounds, as Cr Water soluble................. 0.05 Certain water insoluble . 0.05,Ala Chromyl chloride [14977-61-8) ................. 0.025 0.15 Chrysene [218-01-9] . A2 A2 Clopidol [2971-90-6] . 10 Coal tar pitch volatiles [6007-45-2], as benzene solubles........... -- 0.2,Ala {Cobalt [7440-48-4], as Co Metal, dust & fume___ -- (0.1) Cobalt carbonyl [10210-66-1], as Co .. 0.1 Cobalt hydrocarbonyl [16842-03-6], as Co .. 0.1 Copper [7440-506] Fume............................ 0.2 * Dusts & mists, as Cu . 1 `Cotton dust raw............. 0.2) Cresol [1319-77-3], ail isomers--Skin............. 5 22 {Crotonaldehyde [123-73-9] 2 6 Crufomate [29966-5] ... 5 {Cumene [98-626]--Skin Cyanamide [420-04-2]... 50 245 2 Cyanides [151-506; 143-33-9], as CN-Skm Cyanogen (46019-5]......... 10 5 20 Cyanogen chloride [506-77-4] C 0.3 C 0.6 {Cyclohexane [11062-7]... 300 1,050 Cyclohexanol (108-936] -Skin........... 50 200 -- . -- ... __ (6) (75) (375) 0.6 __ 20 _ (18) 20 (365) (1,300) Substance [CAS #] ADOPTED VALUES TWA STEL ppm" mg/m3" ppm" mg/m3" {Cyclohexanone [108-94-1]-- Skin................................ 25 100 Cyclohexene [118636]... 300 1,015 Cydohexylamine [108-916] ..................... 10 40 Cyclonite [1216241--Skin -- 1.5 {Cyclopentadiene [542-92-7] 75 200 {Cydopentane [287-926].. 600 1,720 `Cyhexatin [13121-785]... -- 5 `2,4-D [94-75-7]................. -- 10 `DOT (Dichlorodiphenyl- trichtoroethane) [50-29-3] ......... Decaborane (1770241-9] -- Skin................................ 0.05 0.3 `Demelon [8065466]-Skin 0.01 0.1 Diacetone alcohol [12342-2] 50 240 1,2-Diaminoethane, see Ethylenediamine `Diazinon [33341-5]--Skin -- . o.i Diazomethane [334686] . 0.2 ' 0.4 Diborane [1928745-7].... 0.1 0.1 1,2-Dibromoethane, see Ethylene dibromide `2-N-Oibutylaminoethanol (1026161-Skin 14 Dibutyl phosphate [107664] 1 5 {Dibutyl phthaJate [84-74-2] -- 5 Dichioroacetyiene [7572-294] ................... C 0.1 C 0.4 o-Dichiorobenzene [95-50-1] C 50 C 300 p-Dichlorobenzene [10646-7] 75 450 3,3'-Dichlorobenzidine [91-94-1]--Skin............. -- A2 `Dichlorodifluoromethane [75-716] ....................... 1,000 4,950 1,3-0ichloro-5,5-dimethyl hydantoin [118-52-5] ... -- 0.2 (100) -- -- -- (150) (900) -- -- 0.15 -- 75 -- -- -- 2 -- -- -- 110 -- -- -- (400) -- -- 3 (400) (2.580) -- -- 0.9 -- 360 -- -- -- 10 (10) -- -- 675 -- -- 0.4 Capital letters A, B, D & E refer to Appendices; C denotes ceiling Emit { See Notice of Intended Changes. * 1986-1987 Addition. (d) Lint-free dust as measured by the vertical elutriator cotton-dust sampler described in the Transactions of the National Conference on Cotton Dust, p. 33, by J.R. Lynch (May 2, 1970). 14 15 ABD0Q136259 Substance (CAS #] ADOPTED VALUES TWA STEL ppm"' mg/m1*' ppm" mg/m1*' 1,1-Dichloroethane [75-34-3] 200 810 1,2-Dichloroethane, see Ethylene dichloride 1,1-Dichloroethylene, see Vtnylidene chloride 1,2-Dichloroethylene [540-59-0] ..................... 200 790 Dichloroethyl ether [111-44-4] --Skin........... 5 30 Dichlorofluoromethane [75-434] ....................... 10 40 Dichloromethane, see Methylene chloride *1,1 -Dichloro-1 -nitroethane [594-72-9] ..................... 2 10 1,2-Dichloropropane, see Propylene dichloride *Dichloropropene [542-756]-Skin........... 1 5 2,2-Oichloropropionic acid [75-99-0] ....................... 1 6 'Oichlorotetrafluoroethane [76-14-2] ........................ 1,000 7,000 Dichlorvos [62-73-7]--Skin 0.1 1 Dicrotophos [141-66-2] -- Skin................................ -- 0.25 Dicyclopentadiene [77-73-6] 5 30 * DicycJopentadienyl iron [102-54-5] ..................... -- 10 "Dieldrin [60-57-1] - Skin .. -- 0.25 Diethanolamine [11142-2] 3 15 Diethylamine [109-89-7] .. 10 30 2-Diethylaminoethanol [100-37-8]--Skin........... 10 50 Diethylene triamine [11140-0]--Skin........... 1 4 Diethyl ether, see Ethyl ether Di-2-ethylhexylphthalate, see Di-sec, octyl phthalate Diethyl ketone [96-22-0] .. 200 705 tDiethyl phthalate [84-66-2] 5 *Difluorodibromomethane [75-61-6] ........................ 100 860 Diglycidyl ether (DGE) [2238-07-5] ................... 0.1 0.5 Dihydroxybenzene, see Hydroquinone Diisobutyl ketone [108-83-8] 25 250 Diisopropylamine [108-18-9]'--Skin........... 5 20 250 250 10 -- -- - -- -- -- -- -- 25 -- -- -- -- 1,010 1,000 60 -- -- - -- -- -- -- -- -- 75 -- (10) -- -- 16 Substance (CAS if] ADOPTED VALUES TWA STEL ppm" mg/m1*' ppm" mg/m1*' Dimethoxymethane, see Methyial 'Dimethyl acetamide [127-19-5]-Skin........... 10 35 -- -- Dimethylamine [12440-3]. 10 18 -- -- Dimethylaminobenzene, see Xylidene Dimethylaniline [121-S-7] (N,N-Dimettiylaniline)-- Skin ................................ 5 25 10 50 Dimethylbenzene, see Xylene Dimethyl carbamoyl chloride [7944-7] ....................... A2 A2 -- -- Dimethyl-1,2-dibromo-2-dichloroethyj phospate, see Naied `Dimethylformamide [68-12-2]--Skin............. 10 30 -- -- 2,6-Dimethyl-4-heptanone, see Diisobutyl ketone '1,1-Dimethylhydrazine [57-14-7]--Skin............. 0.5,A2 1,A2 -- -- Dimethylnitrosoamine, see N-Nitrosodimethylamine * Dimethytphthalate [131-11-3] ..................... - 5- - Dimethyl sulfate [77-78-1]--Skin............. 0.1,A2 0.5,A2 -- -- Dinitolmide [148-01-6]___ 5-- -- 'Dinitrobenzene [528-29-0; 99-65-0; 100-254] (all isomers)-- Skin............. 0.15 1 'Dinitro-o-cresol [534-52-1]--Skin.......... -- 0.2 -- -- 3,5Dinitro-o-toluamide, see Dinitolmide 'Dinitrotoluene [121-14-2]--Skin........... -- 1.5 -- -- 'Dioxane [123-91-1]--Skin___ 25 90 -- -- Dioxathion [78-34-2]--Skin -- 0.2 Diphenyl, see Biphenyl 'Diphenylamine [122-394] . -- 10 -- -- Diphenylmethane diisocyanate, see Methylene bisphenyl isocyanate Dipropylene glycol methyl ether [34590-946]......... 100 600 150 900 Dipropyl ketone [123-19-3] 50 235 -- -- 'Diquat [85-00-7] ............... -- 0.5 -- -- Capital letters A, B, D & E refer to Appendices; C denotes ceiling Bmit t See Notice of Intended Changes. * 1986-1987 Addition. 17 ABDOO136260 Substance [CAS #] ADOPTED VALUES TWA ppm4 STEL ppm4 mg/m34 E "3 E Di-sec, octyl phthalate [117-81-7]...................... 5 10 Disulfiram [97-77-81........... -- 2-- -- Disulfoton [298-04-41......... -- 0.1 -- -- 42,6-Ditert butyt-p-cresol [128-37-0] ..................... 10 (20) Diuron [330-54-1]............. -- 10 -- -- Divinyl benzene [108-57-6] 10 50 -- -- Emery [112-62-9] ............. -- D-- -- Endosulfan [116267] -- _ _Skin................................ 0.1 Endrin [72-20-8]--Skin... -- 0.1 -- -- Enzymes, see Subtilisins Epichlorobydrin [106-89-8]--Skin........... 2 10 (5) EPN [2104-64-5]--Skin .. -- 0.5 -- -- 1.2-Epoxypropane, see Propylene oxide 2.3-Epoxy-1-propanol, see Glycidol Ethane [74-84-0]............... E Ethanethiol, see Ethyl mercaptan Ethanol, see Ethyl alcohol Ethanolamine [141-43-5].. 3 86 15 Ethion [563-12-2]--Skin.. -- 0.4 -- -- 2-Ethoxyethanol [110-80-5]--Skin........... 5 19 2-Ethoxyethyl acetate [111-15-9]--Skin........... 5 27 _ Ethyl acetate [141-78-6] .. 400 1,400 -- -- $Ethyl acrylate [140-88-5]-- Skin................................ 5 20 (25) (100) Ethyl alcohol [64-17-5] ... 1,000 1,900 -- -- Ethylamine [75-04-7]......... 10 18 -- -- Ethyl amyl ketone [541-85-5] 25 130 -- -- Ethyl benzene [100-414] . 100 435 125 545 Ethyl bromide [74-964] .. 200 890 250 1,110 $Ethyt butyl ketone [106-354] ..................... 50 230 (75) (345) Ethyl chloride [75-00-3]... 1,000 2,600 -- -- Ethylene [74-85-1]............. E -- -- -- Ethylene chlorohydrin [107-07-3]-Skin........... C1 C3 Ethylenediamine [107-15-3] 10 25 -- -- Ethylene dibromide [106-934]--Skin........... A2 A2 _ _ Substance [CAS #] ADOPTED VALUES TWA STEL ppm4 mg/m34 ppm4 mg/m34 Ethylene dichloride [107-06-2] ..................... 10 40 Ethylene glycol [107-21-1] \fepor.............................. C 50 C 125 _ _ Ethylene glycol dinitrate [628-966]-Skin........... 0.05 0.3 rL1 Ethylene glycol methyl ether acetate, see 2-Methoxyethyl acetate Ethylene oxide [75-21-8].. 1,A2 2,A2 -- -- Ethylenimine [151-564] -- Skin................................ 0.5 1_ _ Ethyl ether [60-29-7]........ 400 1,200 500 1,500 tEthyl formate [109-944].. 100 300 (150) (450) Ethylidene chloride, see 1,1-Dichloroethane Ethylidene norbomene [16219-75-3] ................. C 5 C25 Ethyl mercaptan [75-061] 0.5 1-- -- _N-Ethylmorpholine [100-74-3]--Skin........... 5 23 _ Ethyl silicate [76164] ... 10 85 -- -- Fenamiphos [22224-92-6]-Skin.... . . 0.1 Fensulfothion [116962] .. Fenthion [56369]--Stan . -- -- 0.1 -- 0.2 -- -- -- Ferbam [14484-64-1]......... -- 10 -- -- Ferrovanadium dust [12604-569] ................. 1 Fibrous glass dust............. -- 10 -- Fluorides, as F................... -- 2.5 -- 3 -- -- Fluorine [7782414]......... 1 22 4 Fluorotrichkiromethane, see Trichlorofluoromethane Fonofos [944-22-9]--Skin. -- 0.1 _ Formaldehyde [50-060] .. 1,A2 1.5,A2 2.A2 3.A2 tFormamide [7612-7]......... (20) (30) (30) (45) Formic acid [64-18-6]___ 5 9-- -- ^Furfural [98-01-1]--Skin.. 2 8 (10) (40) Furfuryl alcohol [96060] - Skin................................ 10 40 15 60 Gasoline [800661-9]......... 300 900 500 1,500 Germanium tetrahydride [7782-662] ................... 0.2 0.6 - - Capital letters A, B, D & E refer to Appendices; C denotes ceiling limit t See Notice of Intended Changes. * 1986-1987 Addition. 18 19 ABDpO 136261 Substance [CAS #]| ADOPTED VALUES TWA STEL ppm" mg/m3" ppm" mg/m3" Glass, fibrous or dust, see Fibrous glass dust Glutaraldehyde [111*30-6]. C 0.2 C 0.7 Glycerin mist [56-81-5]... -- D tGlycidol [556-52-5]........... 25 75 Glycol monoethyl ether, see 2-Ethoxyethanol ^Graphite (Natural) [7782-42-5], see DUSTS ^Graphite (Synthetic)........... -- (D) 'Gypsum [10101-4-4]......... 'Hafnium [7440-58-6]......... Helium [7440-59-7]........... 'Heptachlor [76-44-8]--Skin Heptane [142-82-5] -- -- E -- D 0.5 -- 0.5 (n-Heptane) ................... 400 2-Heptanone, see Methyl n-amyl ketone 3-Heptanone, see Ethyl butyl ketone 1,600 Hexachlorobutadiene [87-68-3]-Skin............. 0.02,A2 'Hexachlorocyclopentadiene [77-47-4] ....................... 0.01 0.24,A2 0.1 Hexachloroethane [67-72-1] 'Hexachtoronaphthalene 10 100 [1335-87-1]--Skin......... 0.2 'Hexafluoroacetone [684-16-2]--Skin........... Hexamethy! phosphoramide 0.1 0.7 [680-31-9]-Skin........... A2 A2 Hexane (n-Hexane) [110-54-3] ..................... 50 Other isomers............... 500 2-Hexanone, see Methyl n-butyl ketone Hexone, see Methyl isobutyl ketone sec-Hexyi acetate [108-84-9] 50 Hexylene glycol [107-41-5] C 25 Hydrazine [302-01 -2]-Skin 0.1,A2 Hydrogen [1333-7443].... E Hydrogenated terphenyis [61788-32-7] ................. 0.5 'Hydrogen bromide 180 1,800 300 C 125 0.1.A2 -- 5 [10035-108] ................. C 3 C 10 Hydrogen chloride [7647-01-0] ................... C5 C7 Hydrogen cyanide [74-908]-Skin............. C 10 C 10 -- (100) -- -- _ -- 500 _ 1,000 -- -- -- _ -- (300) -- -- -- -- 2,000 _ 3,600 -- -- -- Substance [CAS If] ADOPTED VALUES TWA STEL ppm" mg/m3*' ppm" mg/m3*' 'Hydrogen fluoride [7664-39-3], as F.......... C 3 C 2.5 -- 'Hydrogen peroxide [7722-84-1] ................... 1 1.5 -- Hydrogen selenide [7783437-5], as Se ... 0.05 0.2 -- Hydrogen sulfide [7783-06-4]................... 10 14 15 tHydroquinone [123*31-9] . -- 2-- 4-Hydroxy-4-methyl-2-pentanone, see Diacetone alcohol 2-Hydroxypropyl acrylate [999-61-1] - Skin .... 0.5 3-- tlndene [95-13-6]............... 10 45 (15) 'Indium [7440-74-6] & compounds, as In........ -- 0.1 -- Iodine [7553-56-2].......... C 0.1 C 1 -- 'Iodoform [75-47-8].......... 0.6 10 -- 'Iron oxide fume (Fe,0,) [1309-37-1], as Fe ... B2 5-- Iron pentacarbonyi [13463-40-6], asFe ... 'Iron salts, soluble, as Fe . 0.1 -- 0.8 0.2 1-- isoamyl acetate [123-92-2] 100 525 (125) Isoamyl alcohol [123-51-3] 100 360 125 Isobutyl acetate [110-19-0] 150 700 187 isobutyl alcohol [78-83-1] 50 150 (75) Isoocytl alcohol [26952-21-6]--Skin.... 50 270 -- Isophorone [78-59-1]___ C 5 C 25 -- isophorone diisocyanate [4098-71-9]-Skin .... (0.01) (0.09) -- isopropoxyethanol [109-59-1]..................... 25 105 (75) Isopropyl acetate [108-21-4] 250 950 310 Isopropyl alcohol [67-63-0] 400 980 500 Isopropylamine [75-31-0]. 5 12 10 'N-lsopropylaniline [768-52-5]-Skin......... 2 10 -- Isopropyl ether [108-20-3] 250 1,050 310 Isopropyl glycidyl ether (IGE) [4016-14-2]................... 50 240 75 -- -- -- 21 (4) -- (70) -- -- -- -- 1.6 -- (655) 450 875 (225) -- __ -- (320) 1,185 1,225 24 -- 1,320 360 Capital letters A, B, D & E refer to Appendices; C denotes ceiling limit t See Notice of Intended Changes. * 1986*1987 Addition. 20 21 ABDDO136262 ADOPTED VALUES Substance [CAS #] TWA STEL ppm" mg/m3" ppm" mg/m3*' 'Kaolin.................................. Ketone [463-51-4]............. 'Lead [7439-92-1], inorg. dusts & fumes, as Pb . Lead arsenals [10102-48-4], as Pbj(AsOj2................. 0.5 _ Lead chromate [7758-97-6], as Cr.............................. 'Limestone [1317-65-3]... -- 'Lindane [58-89-9]-Skin . -- Lithium hydride [7580-67-8] -- {L.P.G. (Liquified petroleum gas)................................ 1,000 'Magnesite [546-93-0].... -- Magnesium oxide fume [1309-48-4]................... Malathion [121-75-5]-Skin _ Maleic anhydride [108-31-6] 0.25 {Manganese [7439-96-5], as Mn t Dust & compounds___ Fume.............................. -- 'Manganese cyclopentadienyt tricarbonyl [12079-65-1], as Mn--Skin................. Manganese tetroxide [1317-35-7]................... 'Marble/calcium carbonate [1317-65-3]................... _ Mercury [7439-97-6], as Hg--Skin Alkyl compounds........... All forms expect alkyl Vapor .......................... Aryl & inorganic compounds............. _ Mesityl oxide [141-79-7] . 15 Methacrylic acid [79-41-4] 20 Methane [74-82-8]........... E Methanethiol, see Methyl mercaptan Methanol, see Methyl alcohol Methomyl [16752-77-5] .. Methoxychlor [72-43-5] .. -- D_ 0.9 1.5 0.15 0.15 0.05.A2 D 0.5 0.025 ___ ___ -- 1,800 (1,250) D-- 10 10 -- 1_ (C 5) 1 ___ 0.1 1 D 0.01 0.05 0.1 60 70 -- 25 -- ___ 2.5 10 -- 3 ___ _ _ (2,250) -- ___ ___ 3 0.03 100 ___ ___ -- Substance [CAS #1 ADOPTED VALUES TWA STEL ppm" mg/m3" ppm" mg/m3" 2-Methoxyethanol [109-86-4]-Skin........ 5 16 -- _2-Methoxyethyl acetate [11049-6]-Skin......... 5 24 4-Methoxyphenoi [150-76-5] Methyl acetate [79-20-9] . Methyl acetylene [74-99-7] -- 200 1,000 5 610 1,650 -- 250 1,250 Methyl acetylene-propadiene mixture (MAPP)............. 1,000 1,800 1,250 Methyl acrylate [96-33-3]Skin................................ 10 35 __ ' M ethytacryton itrile [126-98-7]--Skin......... 1 3 {Methylal [109-87-5] ......... 1,000 3,100 (1,250) Methyl alcohol [67-56-1] -- Skin................................ 200 260 Methylamine [74-89-5]... 10 12 Methyl amyl alcohol, see Methyl isobutyl carbinol 250 -- {Methyl n-amyl ketone [110-43-0]..................... 50 235 (100) 'N-Methyl aniline [100-61-8] -- Skin............................ 0.5 2 'Methyl bromide [74-83-9]-Skin........... 5 20 __ Methyl n-butyi ketone [591-78-6]..................... 5 20 __ Methyl chloride [74-87-3]. 50 105 100 Methyl chloroform [71-55-6] 350 1,900 450 Methyl 2-cyanoacrylate [137-05-31 ..................... 2 84 {Methylcyclohexane [108-87-2]..................... 400 1,600 (500) {Methylcyclohexanol [25639-42-3]................. 50 235 (75) o-Methylcyclohexanone [583-60-8]--Skin......... 50 230 75 'Methylcyclopentadienyl manganese tricarbonyl [12108-13-3] --Skin, as Mn.............................. 0.2 -- _ -- 760 2,040 2,250 _ _ (3,875) 310 -- (465) __ -- __ 205 2,450 16 (2,000) (350) 345 Capital letters A, B, 0 4 E refer to Appendices; C denotes ceiling Orrat X See Notice of intended Changes. * 1966-1987 Addition. 22 23 ABDOQ136263 Substance[CAS ____________ ADOPTED VALUES TWA STEL ppm" mg/m4*' ppm" mg/m4*' Methyl demeton [8022-00-2]-Skin .... {Methylene bisphenyl " 0.5 isocyanate (MDI) [101-68-8] ..................... (C 0.02) {Methylene chloride [75-09-2] (100) 4,4'-Methylene (C 0.2) (350) bis(2-chloroaniline) [101-14-4]-Skin......... 0.02,A2 0.22.A2 {Methylene bis(4-cyclo- hexylisocyanate) [5124-30-1]................... (C 0.01) *4,4'-Methylene dianiline (C0.11) [107-77-9]-Skin......... 0.1 ,A2 Methyl ethyl ketone (MEK) 0.8.A2 [78-93-3]........................ Methyl ethyf ketone 200 590 peroxide [1338-23-4]... Methyl formate [107-31-3] C 0.2 100 C 1.5 250 5-Methyl-3-heptanone, see Ethyl amyl ketone Methyl hydrazine [60-34-4]--Skin........... C 0.2.A2 C 0.35,A2 Methyl iodide [74-88-4]- Skin................................ Methyl isoamyl ketone 2.A2 10,A2 [110-12-3]..................... Methyl isobutyi carbinol 50 240 [108-11-2]-Skin......... 25 100 Methyl isobutyl ketone [108-10-1]..................... 50 205 Methyl isocyanate [624-83-9]-Skin......... Methyl isopropyl ketone 0.02 0.05 [563-804]..................... Methyl mercaptan [74-93-1] {Methyl methacrylate 200 0.5 705 1 [80-62-6]....................... Methyl parathion 100 410 [298-00-0]-Skin........ -- 0.2 Methyl propyl ketone [107-87-9]..................... Methyl silicate [681-84-5] <r-Methyl styrene [98-83-9] Metribuzin [21087-64-9].. 200 1 50 -- 700 6 240 5 __ (500) -- -- 300 __ 150 -- -- -- 40 75 -- __ -- (125) -- 250 _ 100 -- -- (1,740) ` -- -- 885 375 -- -- -- 165 300 -- -- (510) -- 875 485 Substance (CAS #] ADOPTED VALUES TWA STEL ppm" mg/m4*' ppm" mg/m4*' Mevinphos [7786-34-7] -- Skin................................ 0.01 Molybdenum [7439-98-7], as Mo Soluble compounds.... Insoluble compounds .. -- Monochlorobenzene, see Chlorobenzene Monocrotophos [6923-224] -- Morpholine [110-91-8]-- Skin................................ Naled [300-76-5] -- Skin .. 20 -- Naphthalene [91-20-3] ... 10 /3-Naphthylamine [91-59-8]....................... _ Neon [7440-01-9]............. E Nickel [7440-02-0] Metal.............................. _ * Soluble compounds, as Ni -- Nickel carbonyl [13463-39-3], as Ni___ 0.05 Nickel sulfide roasting, fume & dust, as Ni___ Nicotine [54-11-5]--Skin. Nitrapyrin [1929-824] ... -- -- Nitric acid [7697-37-2]... 2 Nitric oxide [1010243-9]. 25 p-Nitroaniline [100-01-6] -- Skin................................ Nitrobenzene [98-95-3] -- Skin................................ 1 {p-Nitrochlorobenzene [100-00-5]-Skin......... 4-Nitrodiphenyl [92-93-3] . (0.5) -- Nitroethane [79-24-3].... 100 Nitrogen dioxide [10102-44-0]................. 3 Nitrogen trifluoride [7783-54-2]................... 10 Nitroglycerin (NG) [55-63-0]--Skin........... 0.05 0.1 5 10 0.25 70 3 50 Alb -- 1 0.1 0.35 1,A1a 0.5 10 5 30 3 5 (3) Alb 310 6 30 0.5 0.03 -- 30 -- 15 -- MB -- _ -- -- 4 -- _ -- -- 5 _ 0.3 -- MM 105 -- 75 -- _ -- _ -- 20 10 -- _ -- -- 10 _ Capital letters A, B, D & E refer to Appendices; C denotes ceiling limit $ See Notice of Intended Changes. * 1986-1987 Addition. 24 25 ABDOO136264 Substance [CAS #] ADOPTED VALUES TWA STEL ppm4 mg/m3*' ppm4 mg/m3*' `Nitromethane (75-52-5) .. `1-Nitropropane (108-03*2) 100 25 250 90 -- -- {2-Nitropropane (79-46-9) . (C 25, A2) (C 90 A2) -- -- N-Nitrosodimethylamine (62-75-9)-Skin........... - A2 - - Nitrotoluene [99-08-1] -- Skin................................ 2 11 -- -- Nitrotrichloromethane, see Chloropicrin {Nonane (111-84-2]........... 2QQ 1,050 (250) (1,300) Octachloronaphthalene (2234-13-1)--Skin .... -- 0.1 -- 0.3 Octane (111-65-9)............. 300 1,450 375 1,800 Oil mist, mineral (8012-95-1)................... -- 50) -- 10 Osmium tetroxide (20816-12-0), as Os ... 0.0002 0.002 0.0006 0.006 Oxalic acid (144-62-7) ... -- 1-- 2 `Oxygen difluoride (7783-41-7)................... C 0.05 C0.1 -- -- Ozone (10028-15-6)......... 0.1 0.2 0.3 0.6 {Paraffin wax fume [8002-74-2]................... -- 2-- (6) Paraquat [4685-14-7], respirable sizes............. `Parathion [56-38-2]--Skin -- -- 0.1 -- 0.1 -- -- -- Particulate polycyclic aromatic hydrocarbons (PPAH), see Coal tar pitch volatiles Pentaborane [19624-22-7] 0.005 0.01 0.015 0.03 `Pentachloronaphthalene (1321-64-8)................... 0.5 -- -- `Pentachlorophenol (87-86-5)-Skin........... -- 0.5 -- -- *PentaerythritoI (115-77-5] -- D-- -- Pentane (109-66-0)........... 600 1,800 750 2.250 2-Pentanone. see Methyl propyl ketone Perchloroethylene [127-18-4]..................... 50 335 200 1,340 Perchloromethyl mercaptan [594-42-3]..................... 0.1 0.8 -- -- Perchloryl fluoride (7616-94-6)................... 3 14 6 28 Phenacyl chloride, see a-Chloroacetophenone {Phenol [108-95-2] --Skin. 5 19 (10) (38) Substance [CAS ____________ ADOPTED VALUES TWA STEL ppm4 mg/m3*' ppm4 mg/m3*' `Phenothiazine (92-84*2) -- Skin................................ -- 5 N-Phenyl-beta-naphthyl-- amine [135-88-6]........... A2 A2 p-Phenylene diamine (106-50-3)-Skin......... -- 0.1 Phenyl ether (101-84-8), vapor.............................. 1 7 Phenylethylene, see Styrene, monomer Phenyl glycidyl ether (PGE) (122-60-1)..................... 1 6 Phenylhydrazine [100-63-0]--Skin......... 5.A2 20,A2 Phenyl mercaptan (108-98-5)..................... 0.5 2 Phenylphosphine (638-21-1) C 0.05 C 0.25 Phorate [298-02-2]-Skin 0.05 Phosdrin, see Mevinphos Phosgene (75-44-5]......... 0.1 0.4 Phosphine (7803-51-2)... 0.3 0.4 Phosphoric acid [7664-38-2] 1 `Phosphorus (yellow) (7723-14-0)................... 0.1 Phosphorus oxychloride (10025-87-3)................. 0.1 0.6 Phosphorus pentachloride (10026-13-8]................. 0.1 1 Phosphorus pentasulfide [1314-80-3]................... 1 Phosphorus trichloride (7719-12-2)................... 0.2 1.5 {Phthaiic anhydride [85-44-9] 1 6 m-Phthalodinitrile (626-17-5] Picloram (1918-02-1]___ Picric acid [88-89-1] -- Skin -- -- -- 5 10 0.1 {Pindone (83-26-11............. -- 0.1 Piperazine dihydrochloride [142-64-3]..................... -- 5 2-Prvalyi-1,3-indandione, see Pindone -- -- -- 2 10,A2 -- -- -- -- 1 -- 0.5 -- 0.5 (4) -- -- -- -- -- -- -- 14 45.A2 -- -- 0.2 -- 1 3 -- 3 -- 3 3 (24) -- 20 0.3 (0.3) -- Capital letters A, 8, 0 & E refer to Appendices; C denotes ceiling Dint $ See Notice of Intended Changes. * 1986-1987 Addition. (e) As Sampled by method that does not collect vapor. 26 27 ABDOO136265 ADOPTED VALUES Substance TWA STEL {CAS #] ppm" mg/m9" ppm4' mg/m9" Raster of Paris................. _ D Platinum {7440-06-4] Meta).............................. Soluble salts, as Pt___ _1 -- 0.002 Polychlorobiphenyls, see Chlorodiphenyls Polytetrafluoroethylene decomposition products -- B1 Portland cement............... -- D Potassium hydroxide (1310-58-3)................... C2 Propane [74-98-6]............. E -- Propane sultone [1120-71-4] A2 A2 {Propargyl alcohol [107-19-7]--Skin......... 1 2 {0-Propiolactone [57-57-8]. 0.5.A2 1.5,A2 {Propionic acid [79-09-4].. 10 30 {Propoxur [114-26-1]......... -- 0.5 n-Propyl acetate [109-60-4] 200 840 Propyl alcohol [71-23-8] -- Skin................................ Propylene [115-07-1] -- 200 E 500 -- Propylene dichloride [78-87-5]....................... 75 '350 Propylene glycol dinitiate [6423-43-4]-Skin .... 0.05 0.3 Propylene glycol mono methyl ether [107-98-2] 100 360 Propylene imine [75-55-8] -- Skin................................ 2.A2 5.A2 Propylene oxide [75-56-9] 20 50 n-Propyl nitrate [627-13-4] 25 105 Propyne, see Methyl acetylene {Pyrethrum [8003-34-7]... -- 5 {Pyridine [11066-1]........... 5 15 Pyrocatechol, see Catechol {Quinone [106-51-4]........... 0.1 0.4 RDX, see Cyclonite Resorcinol [108-46-3].... 10 45 Rhodium [7440-16-6] Metal.............................. _ 1 Insoluble compounds, as Rh.............................. _ 1 Soluble compounds, as Rh.............................. _ 0.01 -- -- _ -- -- (3) (1.A2) (15) -- 250 250 -- 110 __ 150 _ -- 40 (10) (0.3) 20 _ __ -- -- -- -- (6) (3.A2) (45) (2) 1,050 625 -- 510 __ 540 -- 170 (10) (30) (D 90 _ Substance[CAS #] ADOPTED VALUES TWA STEL ppm" mg/m9" ppm" mg/m9" Ronnel [299-64-3]............. {Rosin core solder pyrolysis 10 products, as formaldehyde................. -- 0.1 -- {Rotenone (commercial) [83-794]....................... Rouge ................................ -- -- 5 __ 0 __ Rubber solvent (Naphtha) 400 1,600 -- Selenium compounds [7782-49-2], as Se .... -- 0.2 -- Selenium hexafluoride (7783-791), as Se .... 0.05 0.2 __ `Sesone [136-78-7]........... -- 10 -- Silane, see Silicon tetrahydride Silicon [744921-3]........... Silicon carbide [40921-2] _ -- 0 __ D-- Silicon tetrahydride [780362-5]................... 5 7-- Silver [744922-4] Metal.............................. -- 0.1 -- Soluble compounds, as Ag.............................. Sodium azide [26629226] Sodium bisulfite [7631-995] -- C0.1 -- 0.01 C 0.3 5 __ __ __ Sodium 2.4-dichloro-phenoxyethyl sulfate,, see Sesone Sodium fluoroacetate [62-746] - Skin......... -- 0.05 -- Sodium hydroxide [1319792]................... -- C 2 -- Sodium metabisulfite [7681-57-4]................... Starch (9005-256)........... __ _ 5 __ 0_ Stibine [780952-3]........... 0.1 0.5 -- {Stoddard solvent [8052-41-3]................... 100 525 (200) Strychnine [57-24-9]......... -- 0.15 -- Styrene, monomer [10942-5]..................... 50 215 100 (0.3) (10) -- -- __ -- -- -- -- _ __ __ 0.15 -- __ -- (1,050) -- 425 Capital letters A, B, D & E refer to Appendices; C denotes ceiling Emit t See Notice of intended Changes. * 1986-1987 Addition. 28 29 ABDOOil 36266 Substance [CAS#] ADOPTED VALUES TWA STEL ppm* mg/m3*' ppm* mg/m3*' Subtilisins (1395-21-7] {Proteolytic enzymes as 100% pure crystalline enzyme)......................... 'Sucrose [57-50-1]............. Sulfotep [3689-24-5]-Skin -C 0.00006W --D -- 0.2 Sulfur dioxide [7446-09-5] 2 5 Sulfur hexafluoride [2551-62-4]................... 1,000 6,000 Sulfuric acid [7664-93-9] . -- 1 Sulfur monochloride [10025-67-9]................. C1 C6 Sulfur pentafluoride [5714-22-7]................... C 0.01 C 0.1 `Sulfur tetrafluoride [7783-60-0]................... C 0.1 C 0.4 Sulfuiyl fluoride [2699-79-8] 5 20 Sulprofos [35400-43-2]... -- 1 Systox, see Demeton 2,4,5-T [93-76-5]............. tTantalum [7440-25-7] -- -- -- 10 (5) TEDP, see Sulfotep Tellurium & compounds [13494-80-9], as Te ... -- 0.1 Tellurium hexafluoride [7783-80-4], as Te .... `Temephos [3383-96-8]... 0.02 -- 0.2 10 TEPP [107-49-3] - Skin . 0.004 0.05 Terphenyls [26140-60-3] . C 0.5 C5 *1,1,1,2-Tetrachloro-2,2- difluoroethane [76-11-9] 500 4,170 *1,1,2,2-Tetrochloro-1,2- difluoroethane [76-12-0] 500 4,170 *1,1,2,2-Tetrachloroethane [79-34-5] -Skin........... 1 7 Tetrachloroethylene, see Perchloroethylene Tetrachloromethane, see Carbon tetrachloride 'Tetrachloronaphthalene [1335-88-2]................... - 2 Tetraethyl lead [78-00-2], as Pb--Skin................. - 0.1 Tetrahydrofuran [109-99-9] 200 590 Tetramethyl lead [75-74-1], as Pb -Skin................. - 0.15 -- -- -- 5 -- -- -- -- -- 10 -- -- -- -- -- -- -- -- -- -- 250 -- -- -- 10 -- -- -- -- -- 40 -- -- (10) -- -- -- -- -- -- -- 735 Substance [CAS #] ADOPTED VALUES TWA STEL ppm* mg/m3* ppm* mg/m3*' Tetramethyl succinonitrile [3333-52-6]-Skin .... 0.5 Tetranitromethane [509-14-8]..................... 1 Tetrasodium pyrophosphate [7722-88-5]................... Tetryl [479-45-8]-Skin .. _ Thallium [7440-28-0] Soluble compounds, as T1--Skin................... *4,4'-Thiobis(6-tertt butyl- m-cresol) [96-69-5].... Thioglycolic acid [68-11-1]--Skin........... 1 Thionyl chloride [7719-09-7]............. Thiram [137-26-8]....... C_l Tin [7440-31-5] Metal..:........................ * Oxide & inorganic compounds, except SnH4, as Sn................... * Organic compounds, as Sn--Skin....................... `Titanium dioxide [13463-67-7]................. o-Toiidine [119^93-7]--Skin A2 Toluene (toluol) [108-88-3] 100 Toluene-2,4-diisocyanate (TDI) [584-84-9] ........... 0.005 o-Toluidine [95-53-4]--Skin 2,A2 m-Toluidine [108-44-1] -- Skin................................ 2 p-Toluidine [106-49-0] -- Skin................................ 2,A2 Toxaphene, see Chlorinated camphene Tributyl phosphate [126-73-8]..................... 0.2 3 8 5 1.5 0.1 10 4 C5 5 2 2 0.1 D A2 375 0.04 9,A2 9 9.A2 2.5 _ _ 150 0.0_2 _ 560 0.15 _ Capital letters A, B, O & E refer to Appendices; C denotes ceiling limit t See Notice of Intended Changes. * 1986-1987 Addition. (f) Based on "high Volume" sampling. (g) For control of general room air, biologic monitoring is essential Air personnel control. 1 30 31 ABDQO136267 Substance [CAS #] ADOPTED VALUES TWA STEL ppm" mg/mw' ppm" mg/mTM Trichloroacetic acid (76-03-9)........................ 1 7 1,2,4-Trichlorobenzene (120-82-1)..................... C 5 C 40 1,1,1-Trichloroethane, see Methyl chloroform 1,1,2-Trichloroethane (79-00-5)-Skin........... Trichloroethylene (79-01-6) 10 50 45 270 Trichlorofluorometiiane (75-69-4)....................... C 1,000 C 5,600 Trichloromethane, see Chloroform Trichloronaphthalene (1321-65-9)-Skin .... -- 5 Trichloronitromethane, see Chloropicrin {1,2,3-Trichloropropane (96-18-4)--Skin............. (50) (300) 1,1,2-Trichloro-1,2,2- trifluoroethane (76-13-1) 1,000 7,600 Tricyclohexyltin hydroxide. see Cyhexatin Triethylamine (121-44-8) . 10 40 Trifluorobromomethane [75-63-8]....................... 1,000 6,100 Trimellitic anhydride [552-30-7]..................... Trimethylamine (75-50-3). 0.005 10 0.04 24 {Trimethyl benzene (2551-13-7)................... 25 125 Trimethyl phosphite (121-45-9)..................... 2 2.4,6-Trinitrophenol, see Picric acid 10 2,4,6-Trinitrophenylmethylnitramine, see Tetryl *2,4,6-Trinitrotoluene (TNT) (118-96-7) --Skin......... - 0.5 'Triorthocresyl phosphate (78-30-8) -Skin........... Triphenyl amine (603-34-9) -- 0.1 5 Triphenyl phosphate (115-86-6)..................... 3 Tungsten (7440-33-7), as W Insoluble compounds .. Soluble compounds -- {Turpentine [8006-64-2]... -- -- 100 5 1 560 Uranium (natural) (7440-61-1) Soluble & insoluble compounds, as U......... 0.2 -- -- 200 -- -- (75) 1,250 15 -- 15 (35) -- -- ~ -- -- (150) -- -- 1,080 -- -- (450) 9,500 60 -- 36 (170) -- -- 10 3 (840) 0.6 32 Substance[CAS fl] ADOPTED VALUES TWA STEL ppm" mg/m*" ppm" mg/m*" n-Valeraldehyde [110-62-3] Vanadium, as V20s 50 175 (1314-62-1) Respirable dust & fume Vegetable oil mists........... _ 0.05 __ D Vinyl acetate [108-05-4].. 10 30 Vinyl benzene, see Styrene Vinyl bromide [593-60-2]. 5,A2 Vinyl chloride (75-01-4) .. 5,Ala Vinyl cyanide, see Acrylonitrile 20,A2 10,Ala Vinyl cyclohexene dioxide (106-87-6)--Skin ......... 10,A2 60,A2 Vinylidene chloride (75-354) 5 20 Vinyl toluene [25013-15-4] {VM & P Naphtha 50 240 (8032-32-4)................... tWarfann (81-81-2)........... 300 1,350 -- 0.1 Welding fumes (NOCt) Wood dust (certain hard -- 5.B2 woods as beech & oak) Soft wood..................... Xylene [1330-20-7] (o-, m-t _ 1 5 p-isomers)..................... 100 435 m-Xylene a.u'-diamine (1477-55-0)--Skin .... __ C 0.1 Xylidine (1300-73-8) -- Skin................................ {Yttrium (7440-65-5)......... {Zinc chloride fume 2 -- 10 (1) (7646-85-71 ................... {Zinc chromate (13530-65-9), as Cr ... Zinc oxide [1314-13-2] Fume.............................. Dust................................ {Zinc stearate (557-05-1).. Zirconium compounds __ 1 -- (0.05.A2) _5 _D _ (D) (7440-67-2), as Zr .... 5 _ 20 _ -- 20 100 (400) __ _ 150 _ __ 60 _ -- 80 485 (1,800) (0-3) 10 655 _ (3) 2 __ 10 (20) 10 Capital letters A, B, D & E refer to Appendices; C denotes ceiSno limit { See Notice of Intended Changes. * 1986-1987 Addition, t NOC = Not otherwise classified. Radioactivity: See Physical Agents section on Ionizing Radiation. 33 i ABDOO136268 Substance SILICA, Si02 DUSTS TLV-TWA Crystalline ' Quartz<h> [14808-60-7]........... .. .0.1 mg/m3, Respirable dust * Cristobalite............... .. .0.05 rag/m3, Respirable dust [14464-46-1] Silica, fused [60676-86-0]........... .. .0.1 mg/m3, Respirable dust Tridymite.................. .. .0.05 mg/m3, Respirable dust [15468-32-3] Tripoli ........................ .. .0.1 mg/3 of contained respirable [1317-95-9] quartz dust. Amorphous 'Diatomaceous earth (uncaJcined)......... ... 10 mg/m3, Total dust [68855-54-9] X Precipitated silica ... .. .(5mg/m3, Respirable dust) 10 mg/m3, Total dust t Silica gel...................... .. .(5 mg/m3, Respirable dust) 10 mg/m3, Total dust * SILCATES Asbestos Amosite ................... .. .0.5 fiber/cc, Ala [12172-73-5] Chrysotiie............... .. .2 fibers/cc,ft> Ala [12001-29-5] Crocidolite............... .. .0.2 fiber/cc, Ala [12001-28-4] Other forms........... .. .2 fibers/cc, Ala {Graphite (natural) -- .. .2.5 mg/m3, Respirable dust [7782-42-5] (5 mg/m3. Total dust) Mica [12001-25-2] ... ... 3 mg/m3, Respirable dust Mineral wool fiber ... ... 10 mg/m3 'Perlite.......................... ... 10 mg/m3, Total dust 'Portland cement......... ... 10 mg/m3, Total dust Soapstone ................. ... 3 mg/m3. Respirable dust 6 mg/m3, Total dust TaJc (containing no asbestos fibers) [14807-96-6]........... .. .2 mg/m3, Respirable dust Talc (containing asbestos fibers) ... . .. Use asbestos TLV-TWA. However, should not exceed 2 mg/ra3 respir able dust. OTHER DUSTS 'Barium sulfate [7727-43-7]...................... 10 mg/m3, Total dust 'Grain dust (oats, wheat, barley)................. 4 mg/m3, Total particulate 'Graphite, synthetic ..........10 mg/m3, Total dust 'Nuisance particulates (see Appendix D)..........10 mg/m3, Total dust tCOAL DUST $ (2 mg/m3 (respirable dust fraction <5% quartz). If > 5% quartz, use respirable quartz value. FOOTNOTES FOR DUSTS (h) Both concentration and percent quartz (if applicable) for respirable dust for the application of this limit are to be deter mined from the fraction passing a size-selector with the charac teristics defined in Appendix F. (i) For silicates, the values are for dust containing no asbestos and < 1 % crystalline silica in the total dust. For coal dust, the , value is for coal dust containing <5% crystalline silica in the 1 respirable fraction. For materials containing more than these percentages of crystalline silica, the environment should be evaluated against the TLV-TWA of 0.1 mg/m3 for respirable quartz. Even where the respirable quartz concentration is less than 0.1 mg/m3, the level of the major component should not exceed its TLV. (j) As determined by the membrane filter method at 400-450 x magnification (4 mm objective) phase contrast illumination. (k) Fibers longer than 5 pm and with an aspect ratio equal to or greater than 3:1. 34 35 NOTICE OF INTENDED CHANGES (for 1986-87) These substances, with their corresponding values, comprise those for which either a limit has been proposed for the first time, or for which a change in the "Adopted" listing has been proposed. In both cases, the proposed limits should be considered trial limits that will remain in the listing for a period of at least two years, if, after two years no evidence comes to light that questions the appropriateness of the values herein, the values will be recon sidered for the "Adopted" list. Documentation is available for each of these substances. Substance [CAS ff\ TWA STEL ppm-1 mg/m*4 ppm* mg/m*4 Acrylamide [79-06-1]--Skin tAmmonium perfluoro- octanoate [3825-26-1]. tCaprolactam [105-60-2] Vapor & aerosol......... Cobalt metal, dust & fume [7440-48-4], as Co ... Enflurane [13838-16-9].. fFormamide (75-12-7J-- Skin.............................. Halothane [151-67-7] ... fHexamethylene diisocyanate [822-06-0]................... flsophorone diisocyanate [4098-71-9]................. fManganese dust & compounds [739-96-5] fMethylene bisphenyl isocyanate [101-68-81. fMethylene chloride [75-09-2]............. fMethylene bis-{4- cyclohexylisocyanate fp-Nitrochlorobenzene [100-00-5]................... 2-Nitropropane [79-46-9] fStearates......................... 1,2,3-Trichloropropane [96-18-4]--Skin ... -- 0.03,A2 -- 0.1 0.25 1 _ 0.05 75 575 10 15 50 400 0.005 0.035 0.005 0.045 OC 0.005 0.055 50.A2 175,A2 - - - - 0.005 0.055 - 0.1 10,A2 0.6 35.A2 (20,A2) n_ and oxide, see DUSTS 10 60 - -- 0.1 -- _ -- -- -- - _ (70,A2) _ Substance [CAS #] fYttrium [7440-65-5] metal and compounds, and Y.............................. tZinc chromates [13530-65-9; 1103-86-9; 37300-23-5], as Cr.... TWA STEL ppm4 mg/m*4 ppm4 mg/m*4 -- 1-- -- 0.01.A1 -- -- -- DELETE THE SHORT-TERM EXPOSURE LIMITS (TLV-STELs) FOR THE FOLLOWING SUBSTANCES: n-Amyl acetate sec-Amyl acetate Asphalt (petroleum) fumes Benzene Biphenyl 2-Butoxyethanoi sec-Butyl acetate tert-Butyl acetate Crotonaldehyde Cumene Cyclohexane Cyclohexanone Cyclopentadiene Cyclopentane Dibutyl phthalate Diethyl phthalate 2,6-Ditert. butyl-p-cresol Ethyl acrylate Ethylbutyl ketone Ethyl formate Furfural Glycidol Hydroquinone Indene Isoamyl acetate Isobutyl alcohol Isopropoxyethanol L.P.G. (liquified petroleum gas) Methylal Methyl n-amyl ketone Methylcyclohexane Methylcyclohexanol Methyl methacrylate Nonane Parafffin wax fume Phenol Phthalic anhydride Pindone Propargyl alcohol 0-Propiolactone Propionic acid Propoxur Pyrethrum Pyridine Quinone Rosin core solder pyrolysis products Rotenone (commercial) Stoddard solvent Trimethyl benzene Turpentine VM & P naphtha Warfarin (a) Parts of vapor or gas per million parts of contaminated air by volume at 25C and 760 torr. (b) Approximate milligrams of substance per cubic meter of air. t 1986-1987 Revision or Addition. Capital tetters A, B, D & E refer to Appendices; C denotes ceiling limit. 36 l 37 ABDOQ136270 i) NOTICE OF INTENDED CHANGES DUSTS Substance SILICA, SiOa TLV-TWA in this booklet: A1-- Confirmed Human Carcinogens; and A2 -- Suspected Human Carcinogens. All steps must be taken to keep exposures to all At carcinogens to a minimum. Workers exposed to A1 carcinogens without a TLV should be property equipped to insure virtually no contact with the carcinogen. Please see the Documentation of the Threshold Um/f Values for a more complete description and derivation of these designations. Amorphous Precipitated silica^.............10 mg/m1, Total dust Silica gelfl............................. 10 mg/m3, Total dust SILICATES111 Coal dust................................ 2 mg/m3 respirable.dust fraction'1) Graphite (natural)...............2.5 mg/m3, Respirable.dust (7782*42-51 OTHER OUSTS tStearates (Appendix D-- Nuisance Particulates) .. 10 mg/m3, Total dust tTantalum [7440-25-7], metal and oxide............... 10 mg/m3, Total dust NOTICE OF INTENT TO CHANGE APPENDIX A Carcinogens The guidelines explain how the Chemical Substances Threshold Limit Values Committee classifies substances found in the occupational environment as either carcinogenic in man or experimental animals. Scientific debate over the existence of biological thresholds for carcinogens is unlikely to be resolved in the near future. For most substances determined to be car cinogenic by the Committee, a value is given to provide practical guidelines for the industrial hygienist to control exposures in the workplace. ; it The Chemical Substances TLV Committee considers infor mation from the following kinds of studies to be indicators of a substance's potential to be a carcinogen in humans: epidemi ology studies, .toxicology studies arid, to a lesser exter>t,. case histories. Because of the long latent period for many carcinogens, and for ethical reasons, it is often impossible to base timely riskmanagement decisions on results from human toxicological studies. In order to recognize the qualitative differences in research results, two categories ol carcinogens are designated ADOPTED APPENDICES APPENDIX A Carcinogens The Committee lists below those substances in industrial use that have proven carcinogenic in man, or have induced cancer in animals under appropriate experimental conditions. Present listing of those substances carcinogenic for man takes two forms: Those for which a TLV has been assigned (la) and those for which en vironmental conditions have not been sufficiently defined to assign a TLV (lb). Ala. Human Carcinogens. Substances, or substances associated with industrial processes, recognized to have carcinogenic or cocarcinogenic potential, with an assigned TLV: Substance Asbestos Amosite.............................. Chrysotile......................... Crocidolite...................... Other forms.................... bis^Chioromethyl) ether. Chromite ore processing (chromate)......................... Chromium (VI), certain water insoluble compounds...................... Coal tar pitch volatiles... Nickel sulfide roasting, fume and dust............... Vinyl chloride...................... |Zinc chromates................. TLV 0.5 fiber**) 2 fibers'*) 0.2 fiber 2 fibers 0.001 ppm 0.05 mg/m3. as Cr 0.05 mg/m3. as Cr 0.2 mg/m3, as b solubles 1 rag/m3, as Ni 5 ppm 0.01 mg/m3. as Cr t 1986-1987 Revision or Addition. 38 39 ABDOO136271 if-1' Alb. Human Carcinogens. Substances, or substances associated , , with industrial processes, recognized to have carcinogenic poten tial without an assigned TLV: 4-Aminodiphenyl -- Skin Benzidine--Skin j'r 0-Naphthylamine 4-Nitrodiphenyl--Skin ,J. For the substances in 1 b, no exposure or contact by any route-- respiratory, skin or oral, as detected by the most sensitive methods--shall be permitted. The worker should be properly equipped to insure virtually no contact with the carcinogen. A2. Industrial Substances Suspect of Carcinogenic Potential for MAN. Chemical substances or substances associated with industrial processes, which are suspect of inducing cancer, based on either 1) limited epidemiologic evidence, exclusive of clinical reports of single cases, or 2) demonstration of carcinogenesis in one or more animal species by appropriate methods. Acrylamide--Skin........................................ 0.03 mg/ra3 Acrylonitrile--Skin.................................... 2ppm Antimony trtoxide production.................. -- Arsenic trioxide production....................... -- Benzene............................................................ 10 ppm Benzo(a)pyrene............................................. -- Beryllium........................... ............................. 2 pg/m3 $1,3-Butadiene.................................................. 10 ppm Carbon tetrachloride--Skin.................... 5 ppm Chloroform....................................................... 10 ppm Chlormethyl methyl ether......................... -- Chromates of lead and zinc, as Cr ... 0.05 mg/m3 Chrysene ......................................................... -- 3,3'-Dichlorobenzidine--Skin.................. -- Dimethyl carbamoyl chloride................. -- 1,1-Dimethylhydrazine--Skjn.................. 0.5 ppm Dimethyl sulfate--Skin.............................. 0.1 ppm Ethylene dibromide--Skin...................... -- Ethylene oxide.................................................... 1ppm Formaldehyde............................................... 1 ppm Hexachlorobutadiene ................................ 0.02 ppm Hexamethyl phosphoramide--Skin ... -- Hydrazine--Skin........................................... 0.1 ppm 4,4'-Methylene bis(2-chloroaniline)-- Skin .............................................................. 0.02 ppm tMethylene chloride...................................... 50 ppm t4,4'-Methylene dianiline............................ 0.1 ppm Methyl hydrazine--Skin............................ C 0.2 ppm Methyl iodide--Skin................................... 2 ppm 2-Nitropropane............................................... 10 ppm N-Nitrosodimethylamine--Skin............. -- 40 N-Phenyl-beta-naphthylamine.................. Phenythydrazine--Skin........................... Propane suitone.......................................... /3-Propiolactone............................................. Propylene imine--Skin.............................. o-Tolidine--Skin.......................................... o-Toluidine--Skin........................................ tp-Toluidine--Skin........................................ Vinyl bromide.................................................. Vinyl cyclohexene dioxide--Skin..... -- 5 ppm -- 0.5 ppm 2 ppm -- 2 ppm 2 ppm 5 ppm 10 ppm For the above, worker exposure by all routes should be carefully controlled to levels consistent with the animal and human ex perience data (see Documentation), including those substances with a listed TLV; Tlie Committee Guidelines for Classification of Experimental Animal Carcinogens The following guidelines are offered in the present state of knowledge as an aid in classifying substances in the occupational environment found to be carcinogenic in experimental animals. A need was felt by the Threshold Limits Committee for such a classification in order to take the first step in developing an ap propriate TLV for occupational exposure. Determination of Approximate Threshold Response Require ment. In order to determine in which category to classify an ex perimental carcinogen for the purpose of assigning an industrial air limit (TLV), an approximate threshold of neoplastic response must be determined. Because of practical experimental diffi culties, a precisely defined threshold cannot be attained. For the purpose of standard-setting, this is of little moment, as an ap propriate risk, or safety, factor can be applied to the approximate threshold, the magnitude of which is dependent on the degree of potency of the carcinogenic response. To obtain the best "practical'' threshold of neoplastic response, dosage decrements should be less than logarithmic. This be comes particularly important at levels greater than 10 ppm (or corresponding mg/m3). Accordingly, after a range-finding deter mination has been made by logarithmic decreases, two additional dosage levels are required within the levels of "effect" and "no effect" to approximate the true threshold of neoplastic response. The second step should attempt to establish a metabolic rela tionship between animal and man for the particular substance ** See Notice of Intended Changes, t 1986-1987 Addition, j 1986-1987 Adoption. 41 ABDOO 1,36272 found carcinogenic in animals. If the metabolic pathways are found comparable, the substance should be classed highly sus pect as a carcinogen for man. If no such relation is found, the substance should remain listed as an experimental animal car cinogen until evidence to the contrary is found. Proposed Classification of Experimental Animal Carcino gens. Substances occurring in the occupational environment found carcinogenic for animals may be grouped into three classes, those of high, intermediate and low potency. In evaluating the incidence of animal cancers, significant incidence of cancer is defined as a neoplastic response which represents, in the judg ment of the Committee, a significant excess of cancers above that occurring in negative controls. EXCEPTIONS: No substance is to considered an occupational car cinogen of any practical significance which reacts by the respira tory route at or above 1000 mg/m3 for the mouse, 2000 mg/m3 for the rat; by the dermal route, at or above 1500 mg/kg for the mouse, 3000 mg/kg for the rat; by the gastrointestinal route at or above 500 mg/kg/d for a lifetime, equivalent to about 100 g T.D. for the rat, 10 g T.D. for the mouse. These dosage limita tions exclude such substances as dioxane and trichlorethylene from consideration as carcinogens. Examples: 1) Dioxane--rats, hepatocellular and nasal tumors from 1015 mg/kg/d, oral; 2) Trichloroethylene--female mice, tumors (30/98 at 900 mg/kg/d), oral. A. Industrial Substances of High Carcinogenic Potency In Experimental Animals. 1. A substance to qualify as a carcinogen of high potency must fulfill one of the three following conditions (a, b, or c) in two animal species: a. Respiratory. Elicit cancer from 1) dosages below 1 mg/m3 (or equivalent ppm) via the respiratory tract in 6- to 7-hour daily repeated inhalation exposures throughout lifetime; or 2) from a single intratracheally administered dose not exceeding 1 mg of particulate, or liquid, per 100 ml or less of animal minute respiratory volume. Examples: 1) bis(chlororaethyl) ether--malignant tumors, rats, at 0.47 mg/m3 (0.1 ppm) in 2 years; 2) Hexamethyl phosphoramide -- nasal squamous cell carcinoma, rats at 0.05 ppm, in 13 months. b. Dermal. Elicit cancer within 20 weeks by skin-painting, twice weekly at 2 mg/kg body or less per application for a total dose equal to or less than 1.5 mg, in a biologically inert vehicle. Examples: 1) 7,12-Dimethylbenz(a)anthracene--skin tumors at 0.12-0.8 mg T.D. in four weeks; 2) Benzo(a)pyrene--mice 12 pg, 3x/wk for 18 mos. T.D. 2.6 mg, 90.9% skin tumors. e. Gastrointestinal. Elicit cancer by daily intake via the gastrointestinal tract, within six months, with a six-month holding period, at a dosage below 1 mg/kg body weight per day; total dose, rat, < 50 mg; mouse, < 3.5 mg. Examples: 1) 7,12-Dimethylbenz(a)anthracene--mammary tumors from 10 mg IX; 2) 3-Methylcholanthrene--tumors at 3 sites from 8 mg in 89 weeks; 3) Benzo(a)pyrene--mice, 3.9% leukemias, from 30 mg T.D. 198 days. j - \ 2. Elicit cancer by all three routes in at least two animal species at dose levels prescribed for high or intermediate potency, j B. Industrial Substances of Intermediate Carcinogenic Potency In Experimental Animals. To qualify as a carcinogen of intermediate potency, a substance should elicit cancer in two animal species at dosages intermediate between those described in A and C by two routes of adminis tration. Example: Carbamic acid ethyl ester--dermal, mammary tumors, mice, 100%, 63 weeks, 500-1400 mg T.D. Gastrointestinal, vari ous type tumors, mice 42 weeks, 320 mg T.D. Gastrointestinal, various type tumors, rats, 60 weeks, 110-930 mg T.D. 1 C. Industrial Substances of Low Carcinogenic Potency in Experimental Animals. To qualify as a carcinogen of low potency, a substance should elicit cancer in one animal species by any one of the three routes of administration at the following prescribed dosages and conditions: 1. Respiratory. Elicit cancer from a) dosages greater than 10 mg/m3 (or equivalent ppm) via the respiratory tract in 6- to 7-hour, daily repeated inhalation exposures, for 12 months' observation period; or b) from intratracheally administered dosages totaling more than 10 mg of particulate or liquid per 100 ml or more of animal minute respiratory volume. Examples: 1) Beryl (beryllium aluminum silicate)--malignant lung tumors, rats, at 15 mg/m3 at 17 months; 2) Benzidine--various tumors, rats, 10-20 mg/m3 at > 13 months. 2. Dermal. Elicit cancer by skin-painting of mice in twice weekly dosages of > 10 mg/kg body weight in a biologically inert vehicle for at least 75 weeks, i.e., > 1.5 g T.D. Examples: 1) Shale tar--mouse, 0.1 ml x 50 = 5 g T.D. 59/60 skin tumors; 2) Arsenic trioxide--man, dose unknown, but esti mated to be high. 3. Gastrointestinal. Elicit cancer from daily oral dosages of 50 mg/kg/day or greater during the lifetime of the animal. 42 43 ABDOO136273 APPENDIX B Substances of Variable Composition B1. PotytetraRuoroethylene* Recomposition products. Thermal decom position of the fluorocarbon chain in air leads to the formation of oxidized products containing carbon, fluorine and oxygen. Be cause these products decompose in part by hydrolysis in alka line solution, they can be quantitatively determined in air as fluoride to provide an index of exposure. No TLV is recommended pending determination of the toxicity of the products, but air con centration should be minimal. B2. Welding Fames-- Total Particulate (NOC)t TLV'TWA, 5 mg/m3 Welding fumes cannot be classified simply. The composition and quantity of both are dependent on the alloy being welded and the process and electrodes used. Reliable analysis of fumes cannot be made without considering the nature of the welding process and system being examined; reactive metals and alloys such as aluminum and titanium are arc-welded in a protective, inert atmosphere such as argon. These arcs create relatively little fume, but an intense radiation which can produce ozone. Simi lar processes are used to arc-weld steels, also creating a rela tively low level of fumes. Ferrous alloys also are arc-welded in oxidizing environments which generate considerable fume, and can produce carbon monoxide instead of ozone. Such fumes generally are composed of discreet particles of amorphous slags containing iron, manganese, silicon and other metallic consti tuents depending on the alloy system involved. Chromium and nickel compounds are found in fumes when stainless steels are arc-welded. Some coated and flux-cored electrodes are formu lated with fluorides and the fumes associated with them can con tain significantly more fluorides than oxides. Because of the above factors, arc-welding fumes frequently must be tested for individual constituents which are likely to be present to determine whether specific TLVs are exceeded. Conclusions based on total fume concentration are generally adequate if no toxic elements are present in welding rod, metal, or metal coating and conditions are not conducive to the formation of toxic gases. Most welding, even with primitive ventilation, does not produce exposures inside the welding helmet above 5 mg/m3. That which does, should be controlled. * Trade Names: Algoflon, Ruon, Teflon, Tetran. t Not otherwise classified (NIX). 44 APPENDIX C Threshold Limit Values for Mixtures When two or more hazardous substances, which act upon the same organ system, are present, their combined effect, rather than that of either individually, should be given primary consider ation. In the absence of information to the contrary, the effects of the different hazards should be considered as additive. That is, if the sum of the following fractions, exceeds unity, then the threshold limit of the mixture should be considered as being exceeded. C1 indicates the observed at mospheric concentration, and T, the corresponding threshold limit (see Example A.1 and B.1). Exceptions to the above rule may be made when there is a good reason to believe that the chief effects of the different harmful substances are not in fact additive, but independent as when purely local effects or different organs of the body are produced by the various components of the mixture. In such cases the threshold limit ordinarily is exceeded only when at least one mem ber of the series (C,/T, + or + C/r2, etc.) itself has a value ex ceeding unity (see Example B.1). Synergistic action or potentiation may occur with some com binations of atmospheric contaminants. Such cases at present must be determined individually. Potentiating or synergistic agents are not necessarily harmful by themselves. Potentiating effects of exposure to such agents by routes other than that of inhala tion is also possible, e.g., imbibed alcohol and inhaled narcotic (trichloroethylene). Potentiation is characteristically exhibited at high concentrations, less probably at low. When a given operation or process characteristically emits a number of harmful dusts, fumes, vapors or gases, it will frequently be only feasible to attempt to evaluate the hazard by measure ment of a single substance. In such cases, the threshold limit used for this substance should be reduced by a suitable factor, the magnitude of which will depend on the number, toxicity and relative quantity of the other contaminants ordinarily present. Examples of processes which are typically associated with two or more harmful atmospheric contaminants are welding, automo bile repair, blasting, painting, lacquering, certain foundry opera tions, diesel exhausts, etc. Examples of TLVs for Mixtures A. Additive effects. The following formulae apply only when the com ponents in a mixture have similar toxicologic effects; they should not be used for mixtures with widely differing reactivities, e.g., hydrogen cyanide and sulfur dioxide. In such case the formula for Independent Effects (B) should be used. 45 ABDOO1-36274 It-. 1. General case, where air is analyzed for each component, the TLV of mixture = Note: tt is essential that the atmosphere be analyzed both qualita tively and quantitatively for each component present, in order to evaluate compliance or non^compliance with this calculated TLV. Example A.1: Air contains 400 ppm of acetone (TLV, 750 ppm), 150 ppm. of sec-butyl acetate (TLV, 200 ppm) and 100 ppm of methyl ethel ketone (TLV, 200 ppm). Atmospheric concentration of mixture = 400 + 150 + 100 = 650 ppm of mixture. 400 750* 150 200" 100 = 0.53 + 0.75 + 0.5 = 1.78 200~ Threshold Limit is exceeded. 2. Special 'casewhen the source of contaminant is a liquid mix ture and the atmospheric composition is assumed to be simi lar to that of the original material, e.g., on a time-weighted average exposure basis, all of the liquid (solvent) mixture even tually evaporates. When the percent composition (by weight) of the liquid mixture is known, the TLVs of the constituents must be listed in mg/m3. TLV of mixture = 1 1 + b + 8 + ... TLV, TLV,, TLVC TLV, Note: In order to evaluate compliance with this TLV, field sam pling instruments should be calibrated, in the laboratory, for response to this specific quantitative and qualitative air-vapor mixture, and also to fractional concentrations of this mixture, e.g., 1/2 the TLV; 1/10 the TLV; 2 x theTLV;10 x the TLV; etc.) Example A.2: Liquid contains (by weight): 50% heptane: TLV = 400 ppm or 1600 mg/m3 1 mg/m3 = 0.25 ppm 30% methyl chloroform: TLV -- 350 ppm or 1900 mg/m3 1 mg/m3 3 0.18 ppm 20% perchloroethylene: TLV = 50 ppm or 335 mg/m3 1 mg/m3 = 0.15 ppm TLV of Mixture = ----------------------------------------0.5 + _013_ + _012_ 1600 1900 "335* 1 0.00031 + 0.00016 + 0.0006 * - 935 mg/m3 0.00107 of this mixture 50% or (935)(0.5) = 468 mg/m3 is heptane 30% or (935)(0.3) = 281 mg/m3 is methyl chloroform 20% or (935)(0.2) = 187 mg/m3 is perchloroethylene These values can be converted to ppm as follows: heptane: 468 mg/m3 x 0.25 = 117 ppm methyl chloroform: 281 mg/m3 x 0.18 = 51 ppm perchloroethylene: 187 mg/m3 x 0.15 = 29 ppm TLV of mixture = 117 +51+ 29 = 197 ppm, or 935 mg/m3 8. Independent effects. TLV for mixture = Example B.l: Air contains 0.15 mg/m3 of lead (TLV, 0.15) and 0.7 mg/m3 of sulfuric acid (TLV, 1). 015 =i; 0.15 JLZ_ = 0.7 1 Threshold limit is not exceeded. C. TLV for mixtures of mineral dusts. For mixtures of biologically active mineral dusts the general formula for mixtures given in A.2 may be used. APPENDIX D Some Nuisance Particulates `TLV-TWA, 10 mg/m3 of total dust o-Alumina (AljOJ Calcium carbonate Calcium silicate Cellulose (paper fiber) Emery Glycerin mist Gypsum Kaolin Limestone Magnesite Marble Mineral wool fiber Pentaerythritol Plaster of Paris Portland cement Rouge Silicon Silicon carbide Starch fStearates Sucrose Titanium dioxide 46 47 ABj Vegetable oil mists (except castor oil, cashew nut or similar irritant oils) JZinc stearate Zinc oxide dust (i) When toxic impurities are not present, e.g.. quartz < 1%. (I) As defined in the Introduction, t See Notice of Intended Changes. Acetylene Argon Ethane Ethylene Helium APPENDIX E Some Simple Asphyxiants'" Hydrogen Methane Neon Propane Propylene (I) As defined in the Introduction. APPENDIX F Chemical Substances and Other Issues Under Study* Chemical Substances Acetomethylchloride Acetophenone Acetylacetone Acrylic acid Allyl chloride Bromodichloromethane Ceramic fibers Dibutyl phenyl phosphate Dichlorvos Dinitrotoluene Epichlorohydrin Ethylamines Gasoline (unleaded) Graphite fibers Hexachiorocyclopentadiene Hydrazine Jet, petroleum and diesel fuels Malathion 48 Methyl bromide Methyl hydrazines Mineral wool fibers Naled Nitrous oxide Pentachlorophenol Perchloroethylene. Persulfates Petroleum solvents o-Phenytenediamine Propylene dichloride Rosin core solder pyrolysis p Skydrol hydraulic fluid 1.1.1.2-Tetrachloro-2,2-difluor> 1.1.2.2-Tetrachloro-l ,2-difluon 1.1.2.2-Tetrachloroethane Thiram Trichloroethylene Other Issues 1. Particle Size-Selective Sampling Criteria for Airborne Particu late Matter8 For chemical substances present in inhaled air as suspensions of solid particles or droplets, the potential hazard depends on particle size as well as mass concentration because of: 1) effects of particle size on deposition site within the respiratory tract, and 2) the tendency for many occupational diseases to be associated with material deposited in particular regions of the respiratory tract. ACGIH has recommended particle size-selective TLVs for crys talline silica for many years in recognition of the well estab lished association between silicosis and respirable mass concentrations. It now has embarked on a re-examination of other chemical substances encountered in particulate form in occupational environments with the objective of defining: 1) the size-fraction most closely associated for each substance with the health effect of concern, and 2) the mass concentration within that size fraction which should represent the TLV. The Particle Size-Selective TLVs (PSS-TLVs) will be expressed in three forms, e.g., a. Inspirabte Particulate Mass TLVs (IPM-TLVs) for those materials which are hazardous when deposited anywhere in the respiratory tract. b. Thoracic Particulate Mass TLVs (TPM-TLVs) for those materials which are hazardous when deposited anywhere within the lung airways and the gas-exchange region. c. Respirable Particulate Mass TLVs (RPM-TLVs) for those materials which are hazardous when deposited in the gasexchange region. The three particulate mass fractions described above are de fined in quantitative terms as follows: a. Inspirable Particulate Mass consists of those particles that are captured according to the following collection efficiency regardless of sampler orientation with respect to wind direction: E = 50(1 + exp[-0.06 dj) 10; for 0 <d,<E 100 pm Collection characteristics for da>100 jim are presently unknown. E is collection efficiency in percent and da is aero dynamic diameter in nm. b. Thoracic Particulate Mass consists of those particles that penetrate a separator whose size collection efficiency is described by a cumulative lognormal function with a median aerodynamic diameter of 10 1.0 f/m and with a geo metric standard deviation of 1.5 (0.1). c. Respirable Particulate Mass consists of those particles that penetrate a separator whose size collection efficiency is 49 described by a cumulative lognormal function with a median aerodynamic diameter of 3.5 fim 0.3 pm and with a geo metric standard deviation of 1.5 (0.1). This incorporates and clarifies the previous ACGIH Respirable Dust Sampling Criteria. These definitions provide a range of acceptable performance for each type of size-selective sampler. Further information is available on the background and performance criteria for these particle size-selective sampling recommendations.11-35 References 1. ACGIH: Particle Size-Selective Sampling in the Workplace, 60 pp. Cincinnati. Ohio (1984). 2. Particle Size-Selective Sampling in the Workplace. Ann. Am. Coni. Govt. Ind. Hyg. 11:23-100 (1984). 3. Chapter 7. Performance Considerations for Size-Selective Samplers (revised). Submitted to Ann. Am. Coni. Govt. Ind. Wyg.(1986). 2. Should the TLVs currently expressed as "total dust"c be changed to "inspirable particulate mass" (as defined in the above criteria) without changing the numerical value? 3. Applications of TLVs to altered work schedules. A Information, data especially, and comments are solicited to assist the Committee in its deliberations and in the development of draft documents. Draft documentations are used by the Committee to decide what action, if any, to recommend on a given question. B Includes redefinition of respirable dust and notice of additional size-selective concen trations to be used in TLVs for particulate matter under consideration for revision. c As used tor the mineral dusts. APPENDIX G Registered Trade Names Trade Name Abate Ammate Azodrin Baygon Baytex Bidrin Bolstar Butyl Cellosolve Cellosolve acetate Coyden Generic Name Temephos Ammonium sulfamate Monocrotophos Propoxur Fenthion Dicrotophos Sulprofos 2-Butoxyethanol 2-Ethoxyethyl acetate Clopidol CAS No. 3383-96-8 7773-06-0 6923-22-4 114-26-1 55-38-9 141-66-2 35400-43-2 111-76-2 111-15-9 2971-90-6 50 Crag herbicide Dasanit Delnav Dibrom Difolatan Disyston Dursban Dyfonate Furadan Guthion Lannate Methyl Cellosolve Methyl Cellosolve acetate Nemacur Nialate N-Serve Plval Plictran Sencor Sevin Teflon Thimet Thiodan Tordon Zoalene Sesone Fensulfothion Dioxathion Naied Captafol Disulfoton Chlorpyrifos Fonofos Carbofuran Azinphos-methyl Methomyl 2-Methoxyethanoi 2-Methoxyethyl acetate Fenamiphos Ethion Nitrapyrin Ptndone Cyhexatin Metribuzin Carbary! Polytetrafluoro- ethylene Phorate Endosulfan Picloram Dinitolmide 136-78-7 115-90-2 78-34-2 300-76-5 2425-06-1 298-04-4 2921-68-2 944-22-9 1563-66-2 86-50-0 16752-77-5 109-84-4 110-49-6 22224-92-6 563-12-2 1929-82-4 83-26-1 1312 1-70-5 21087-64-9 63-25-2 9002-84-0 298-02-2 115-29-7 1918-02-1 148-01-6 51 ABDOfl* 36277 Biological Exposure Indices Adopted by ACGIH with Intended Changes for 1986-87 ABD00B6278 1985-86 BIOLOGICAL EXPOSURE INDICES COMMITTEE Vera F. Thomas, Ph.D., University of Miami--Chair Larry K. Lowry, Ph.D., NIOSH J. Thomas Pierce, Ph.D., University of North Alabama Jon Rosenberg, M.D., California Dept, of Health Services/Dept. of Industrial Relations Anthony A. Thomas, M.D., Retired Janice W. Yager, Ph.D., University of Califomia-Berkeley CONSULTANTS Mitchell R. Zavon, M.D. 54 INTRODUCTION BIOLOGICAL EXPOSURE INDICES Biological Exposure Indices (BEIs) represent warning levels of biological response to the chemical, or warning levels of the chemical or its metabolic produces) in tissues, fluids, or exhaled air of exposed workers, regardless of whether ihe chemical was inhaled, ingested, or absorbed via skin. Introduction of the BEI is a step in the evolution of the concept of TLVs. The BEI provides the health personnel with an additional tool to provide protection for the worker. Use of body fluids and appendages such as hair or nails for measuring the absorbed amount of a substance has long been a standard practice for certain substances. Lead is a classical example of a substance for which blood concentrations have long been considered the critical value in determining "safe" versus "unsafe" exposures. Two problems hindered the wider use of biological measurements as indicators of "safe" environmental exposures: 1) the relatively wide range in individual response to a substance and the wide range of "normaT that has to be con sidered; and 2) the lack of simple specific analytical methods of sufficient sensitivity. Both problems are capable of solution, and we believe that sufficient progress has been made to begin utiliz ing selected BEIs which can be used as a guide to "safe" ex posures to toxic chemicals. The BEI is considered supplementary to an airborne TLV. TLVs are intended to provide the industrial hygienist with an additional measure to aid in the design of engineering controls or for temporary use of personnel protective equipment which win pro tect almost all exposed workers from untoward effects of chemi cal exposure. In principle, TWA-TLVs are designed to prevent exposures which may cause acute or chronic adverse effects. They are also intended to avoid attendant deterioration of normal physiological function. This approach is based on the assumption that for nearly all workers there is a tolerable exposure limit and a tolerable body burden of airborne material. If this assumption is valid, there should be a range of safe biologically insignificant changes of various measures of body function. TLVs are a measure of the composition of the external en vironment surrounding the worker. BEIs are a measure of the amount of chemical absorbed into the body. The concept of the BEI is particularly useful in evaluating exposures to substances with significant absorption through the skin. The biological determinant on which the BEIs are based can furnish two kinds of information useful in the control of worker exposure; 1) measure of the worker's individual response, and 2) measure of the worker's individual overall exposure. Measurements of response furnish an estimate of the physiological status of the worker and can be made by, a) determining changes in the amount of a critical biochemical constituent, b) determining changes in sa ABDOO136279 activity of a critical enzyme, and c) determining changes in a physiological function. Measurements of exposure can be made by, a) determining the chemicai in exhaled air, urine, blood, hair, nails, body tissues and fluids, b) determining the metabolite(s) of the chemical in tissues and fluids, and c) determining the extent of specific biochemical and physiological changes induced by the chemical. Recommended values of BEIs are based on data obtained in epidemiological and field studies or determined as bioequiva lent to a TLV by means of pharmacokinetic analysis of data from controlled human studies. Most chemicals (including organic sol vents) are initially absorbed and eliminated fairly rapidly--usually with initial half-life values measured in a few hours or even minutes. Rapidly changing concentrations in body fluids complicate the in terpretation of data and the average body burden of a chemical attained during a work shift can easily be over-predicted or under predicted. Furthermore, biological measurements fail in most in stances to detect transient periods of over-exposure during the work shift. Because elimination of chemicals and their metabolic products, as weil as biological changes induced by exposure to the chemical, are kinetic events, the listed BEIs are strictly related to 8-hour exposures and to the specified timing for the collection of biological samples. Factors to be considered. There are other factors to be con sidered when the BEI is applied. Among the factors which must be considered in using BEIs are: a) changes induced by strenu ous physical activity; b) changes induced by environmental con ditions (altitude, heat, diet, etc.); c) changes induced by water intake; d) changes in physiological functions induced by preexisting disease or congenital variation; e) changes in metabolism induced by congenital variation of metabolic pathways; and f) changes in metabolic pathway induced by simultaneous administration of another chemical (induction or inhibition of activity of a critical enzyme by medication or by preexposure or coexposure to another chemical). For BEIs based on urine analysis, a simple measurements of concentrations can provide sufficient information on exposure, but in many instances, measurements of elimination rates provide more precise information. Urinary concentrations related to creati nine represent a reasonable compromise between the accuracy of the information and the technical means of obtaining the data. Some BEIs are not protective of an identified population, or are nonspecific. The correlation between the exposure and bio logical determinant is weakened by variables introduced by large interindividual variation in response to the chemical or by time factors and fluctuation of exposure concentration. In such cases the BEIs carry the following notations: "R" Notation. Indicates that an identifiable population group might have an increased susceptibility to the effect of the chem ical which leaves it unprotected by the recommended BEI. The specific documentation should be consulted for detailed infor mation. Notation. Some determinants are nonspecific, since different chemicals may bear the same biological response. Such BEIs carry notation. These nonspecific tests are preferred because they are easy to use and, in many instances, offer a better correlation between exposure and response than specific tests. In such instances, a BEI for a specific less quan titative biological determinant is recommended as a confirma tory test. The documentation should be consulted for information on factors affecting interpretation of such a BEI. "* " Notation. Indicates that the biological determinant is a specific indicator of exposure to the chemical but the quan titative interpretation of the measurements is very ambiguous, and that the relationship between the TLV and BEI is marked ly weakened by variables or time factors, fluctuation of exposure concentrations, and by other circumstantial variables. Such biological determinants should be used as confirmatory tests; and their BEIs should be applied cautiously, mainly for confir mation of exposures indicated by nonspecific BEIs. "t" Notation. The determinant is usually present in the biological specimens collected from subjects without occupa tional exposure. For information on background levels consult the documentation. "6" Notation. Because of the wide interindividual varia tion in response to some chemicals, the BEI is in some in stances recommended as a mean value of a group test for workers subjected to a similar level of occupational exposure, rather than as an index for an individual. Such BEIs carry "Q" notation. The table includes BEIs for which a sufficient data base is avail able and on which the committee took action. Some BEIs are more suitable for correlation with TLV-TWAs than others. Other BEIs are preferable for evaluating recent exposure or for confirmation of ex posure. For specific instances the documentation should be con sulted. Workers are not expected to suffer any id effects as long as the described measurement of the determinants are maintained within limits of the recommended BEIs. Measurements outside these limits are not necessarily indicators of a disease process. However, if these deviate measurements persist, it is an indica tion that the individual should be examined by a physician to determine whether there is any health effect. The workplace and work practices should be investigated further. NOTE: ft Is strongly advisable to consult the specific documen tation published In the Documentation of Threshold Limit Values and Biological Exposure Indices, 5th edition, before In voking the BEIs listed In the the following table. 56 57 ABD00t36280 ]l $ I So CO s 38 Sio &CL CNI !-- CNJ JDaE|EE i-0VC\JC\l'-00 T3 a5 SI P g 'S -3 s '3 -o fi s Si g gw ~ B <S ? of SSf 2u ^c . E j E B E E o CM CO i-- CM & 0.0), E6E| ss| eo .- o> E E " gI g g o'f o g ADOPTED BIOLOGICAL EXPOSURE INDICES t i' M g m -- cm S 5, J3 i R .1 B E1 S Si CO CL !S aB> 79s 5o o E 3 a> 2> S C/3 CO 56 S > <D =. , s& .0 .0 8 a S ic 2 f 85 B 59 ABDOO136281 II*I u> <r M II EE "3a>. "a&. ss "3> E a E jg 5 11 5 = IB uj a. & 1 I || s S.1S ^ '9> *3) x xx t'a, tf s S5 E E E s3 V) a s -g *5 g T3 -C l<a iTa !9 o w c 5 I i SB ii 6 LU ie NOTICE OF INTENT TO ESTABLISH S' I <a -f Ie esi o ! T3 ^ S -* ,, g| si ? *3 HI 60 I$ a 2- sa 8 3 *- se 5 jsE l ~ ^-1 e a ill uj a Ef-S cj uj uS . .0 S= e ofta. $i Ill l; R I- u. oz . LU XCL 61 Irr Chemical Substances Under Study to Establish BEIs Acetone Chromium Fluoride Malathion Mercury Nitrobenzene Parathion Perchloroethylene Polychlorinated biphenyls I I I TLVs Threshold Limit Values for Physical Agents in the Work Environment Adopted by ACGIH I. \ with Intended Changes for 1986-87 A 1985-66 PHYSICAL AGENTS TLV COMMITTEE David H. Sliney, U.S. Army Environmental Hygiene Agency--Chair Peter A. Breysse, University of Washington Irving H. Davis, Michigan Dept, of Public Health Zory R. Glaser, Ph.D., National Center for Devices & Radio logical Health/FDA Allan P. Heins, Ph.D., OSHA--Secretary Herbert H. Jones, Retired Edward J. Largent, Retired John C. Mitchell, USAF Anthony M. Muc, Ph.D. Ontario Ministry of Labour William E. Murray, NIOSH Wordie H. Parr, Ph.D., Retired Jukka Pekka Starck, Finnish Institute of Occupational Health Robert T. Wangemann, Ph.D., NCRP Donald E. Wasserman, Wright State University Thomas K. Wilkinson, National Institutes of Health CONSULTANTS Gerald V. Coles Richard A. Ilka, M.D. Robert N. Ligo, M.D. 64 INTRODUCTION PHYSICAL AGENTS These threshold limit values refer to levels of physical agents and represent conditions under which it is believed that nearty all workers may be repeatedly exposed day after day without adverse effect. Because of wide variations in individual susceptibility, exposure of an occasional individual at, or even below, the threshold limit may not prevent annoyance, aggravation of a pre existing condition, or physiological damage. These threshold limits are based on the best available infor mation from industrial experience, from experimental human and animal studies, and when possible, from a combination of the three. These limits are intended for use in the practice of indus trial hygiene and should be Interpreted and applied only by a person trained In this discipline. They are not intended for use, or for modification for use, 1) in the evaluation or control of the levels of physical agents in the community, 2) as proof or disproof of an existing physical disability, or 3) for adop tion by countries whose working conditions differ from those In the United States of America. These values are reviewed annually by the Committee on Threshold Limits for Physical Agents for revision or additions, as further information becomes available. The ACGIH disclaims liability with respect to the use of TLV8 in a manner inconsistent with their intended use as stated herein. Notice of intent-- At the beginning of each year, proposed actions of the Committee for the forthcoming year are Issued in the form of a "Notice of Intent." This notice provides not only an opportunity for comment, but also solicits suggestions of physical agents to be added to the list. The suggestions should be accom panied by substantiating evidence. Definitions--Two categories of Threshold Limit Values (TLVs) are specified, herein, as follows: a) Threshold Limit Value-Time Weighted Average (TLV-TWA)-- the time-weighted average concentration for a normal 8-hour work day and a 40-hour workweek, to which nearty all workers may be repeatedly exposed day after day, without adverse effect. Exam ples of their use can be found in the TLVs for Heat and Noise. b) Threshold Limit Value-Ceiling (TLV-C)~\t\e concentration that should not be exceeded even instantaneously, as in the case of 115 dBA limit for noise. Physical Factors. It is recognized that combinations of such physical factors as heat, ultraviolet and ionizing radiation, humidity, abnormal pressure (altitude), and the like may place added stress on the body so that the effects from exposure at a threshold limit may be altered. Also, most of these stresses may act adversely to increase the toxic response of a foreign substance. Although 65 ABDOO136284 most threshold limits have built-in safety factors to guard against adverse effects to moderate deviations from normal environments, the safety factors of most substances are not of such a magni tude as to take care of gross deviations. For example, continuous work at WBGT temperatures above 30C (86F), or overtime ex tending the workweek more than 25%, might be considered gross deviations. In such instances judgment must be exercised in the proper adjustments of the Threshold Limit Values. ADOPTED THRESHOLD LIMIT VALUES HEAT STRESS These Threshold Umit Values (TLVs) refer to heat stress con ditions under which it is believed that nearly all workers may be repeatedly exposed without adverse health effects. The TLVs shown in Table 1 are based on the assumption that nearly all ac climatized, fully clothed workers with adequate water and salt in take should be able to function effectively under the given working conditions without exceeding a deep body temperature of Since measurement of deep body temperature is impractical for monitoring the workers' heat load, the measurement of environ mental factors is required which most nearly correlate with deep body temperature and other physiological responses to heat. At the present time Wet Bulb Globe Temperature Index (WBGT) is the simplest and most suitable technique to measure the environmental factors. WBGT values are calculated by the following equations: 1. Outdoors with solar load: WBGT = 0.7 NWB + 0.2 GT + 0.1 DB 2. Indoors or Outdoors with no solar load: WBGT = 0.7 NWB + 0.3 GT where: WBGT s Wet Bulb Globe Temperature Index NWB b Natural Wet-Buib Temperature DB b Dry-Bulb Temperature GT b Globe Temperature 66 TABLE 1 Permissible Heat Exposure Threshold Limit Values (Values are given in C WBGT) Work--Rest Regimen Continuous work 75% Work 25 % Rest, each hour 50% Work 50% Rest, each hour 25% Work 75% Rest, each hour Work Load Light 30.0 Moderate 26.7 Heavy 25.0 30.6 28.0 25.9 31.4 29.4 27.9 32.2 31.1 30.0 The determination of WBGT requires the use of a black globe ther mometer, a natural (static) wet-bulb thermometer, and a dry-bulb thermometer. Higher heal exposures than shown in Table 1 are permissi ble if the workers have been undergoing medical surveillance and it has been established that they are more tolerant to work in heat than the average worker. Workers should not be permitted to con tinue their work when their deep body temperature exceeds 3S.0eC. Evaluation and Control I. Measurement of the Environment The instruments required are a dry-bulb, a natural wet-bulb, a globe thermometer, and a stand. The measurement of the environmental factors shall be performed as follows: A. The range of the dry and the natural wet bulb thermometer shall be -5C to 50C with an accuracy of 0.5C. The dry bulb ther mometer must be shielded from the sun and the other radiant sur faces of the environment without restricting the airflow around the bulb. The wick of the natural wet-bulb thermometer shall be kept wet with distilled water for at least 1/2 hour before the tempera ture reading is made. It is not enough to immerse the other end of the wick into a reservoir of distilled water and wait until the whole wick becomes wet by capillarity. The wick shall be wetted by direct application of water from a syringe 112 hour before each reading. The wick shall extend over the bulb of the thermometer, covering the stem about one additional bulb length. The wick should always be clean and new wicks should be washed before using. 8. A globe thermometer, consisting of a 15 cm (6-inch) diameter 67 hollow copper sphere painted on the outside with a matte black finish or equivalent, shall be used. The bulb or sensor of a ther mometer (range -58 to + 100C with an accuracy of 0.5C) must be fixed in the center of the sphere. The globe thermometer shaft be exposed at least 25 minutes before it is read. C. A stand shall be used to suspend the three thermometers so that they do not restrict free air flow around the bulbs, and the wetbulb and globe thermometer are not shaded. D. It is permissible to use any other type of temperature sensor that gives identical reading as that of a mercury thermometer under the same conditions. E. The thermometers must be so placed that the readings are representative of the condition where the men work or rest, respec tively. TABLE 2 Assessment of Work Load> Average values of metabolic rate during different activities. A. Body position and movement kcal/min Sitting Standing Walking Walking up hill 0.3 0.6 2.0-3.0 add 0.8 per meter (yard) rise B. Type of Work Average kal/min Hand work light heavy Work with one arm light heavy Work with both arms light heavy Work with body light moderate heavy very heavy 0.4 0.9 1.0 1.7 1.5 2.5 3.5 5.0 7.0 9.0 Range kcal/min 0.2-1.2 0.7-2.5 1.0-3.5 2.5-15.0 68 TABLE 3 Activity Examples'* Light hand work: writing, hand knitting Heavy hand work: typewriting Heavy work with one arm: hammering in nails (shoemaker, upholsterer) Light work with two arms: filing metal, planing wood, raking of a garden Moderate work with the body: cleaning a floor, beating a carpet Heavy work with the body: railroad track laying, digging, barking trees Sample Calculation Assembly line work using a heavy hand tool. A. Walking along 2.0 kcal/min B. Intermediate value between heavy work with two arms and light work with the body 3.0 kcal/min Subtotal: 5.0 kcal/min C. Add for basal metabolism 1.0 kcal/min Total: 6.0 kcal/min The methodology outlined above is more fully explained by Minard.'3-*' II. Work Load Categories Heat produced by the body and the environmental heat together determine the total heat toad. Therefore, if work is to be performed under hot environmental conditions, the workload category of each job shall be established and the heat exposure limit pertinent to the workload evaluated against the applicable standard in order to protect the worker exposure beyond the per missible limit. A. The work load category may be established by ranking each job into light, medium, and heavy categories on the basis of type of operation. Where the work load is ranked into one of said three categories, i.e.. 69 ABD60-B6286 Btu/hr Rote of Work Figure 1--Permissible Heat Exposure Threshold Limit Values. (1) light work (up to 200 kcal/hr or 800 Btu/hr): e.g., sitting or standing to control machines, performing light hand or arm work, (2) moderate work (200*350 kcal/hr or 800*1400 Btu/hr): e.g., walking about with moderate lifting and pushing, or (3) heavy work (359-500 kcal/hr or 1400*2000 Btu/hr): e.g., pick and shovel work, The permissible heat exposure limit for that workload shall be de termined horn Table 1. B. The ranking of the job may be performed either by measuring the worker's metabolic rate while performing his job or by estimating his metabolic rate with the use of Tables 2 and 3. Additional tables available in the literature*") may be utilized also. When this method is used the permissible heat exposure limit can be deter mined by Figure 1. III. Work-Rest Regimen The permissible exposure limits specified in Table 1 and Figure 1 are based on the assumption that the WBGT value of the resting place is the same or very close to that of the workplace. Where the WBGT of the work area is different from that of the rest area 70 a time-weighted average value should be used for both environ mental and metabolic heat. When time-weighted average values are used, the appropriate curve on Figure 1 is the solid line labeled "continuous." The time-weighted average metabolic rate (M) shall be deter mined by the equation: Av M = M, x t, + Mj x t, + ... + M, x t, t, + t, + ... + t. where M1t M2...and Mn are estimated or measured metabolic rates for the various activities and rest periods of the worker dur ing the time periods t1, ^...and t,, (in minutes) as determined by a time study. The time-weighted average WBGT shall be determined by the equation: Av. WGBT = WBGT, x t, + WBGT, x tg + ... + WBGT. X t,, _____ where WBGT,, WBGT2 ... and WBGTn are calculated values of WBGT for the various work and rest areas occupied during total time periods t,, ^... and t,, are the elapsed times in minutes spent in the corresponding areas which are determined by a time study. Where exposure to hot environmental conditions is continuous for several hours or the entire work day, the time-weighted averages shall be calculated as hourly time-weighted average, i.e., t, + tj + ... t,, a 60 minutes. Where the exposure is intermittent, the time-weighted averages shall be calculated as two-hour timeweighted averages, i.e., t, + tj + ... + t,, - 120 minutes. The permissible exposure limits for continuous work are ap plicable where there is a work-rest regimen of a 5-day work week and an 8-hour work day with a short morning and afternoon break (approximately 15 minutes) and a longer lunch break (approximately 30 minutes). Higher exposure limits are permitted if additional rest ing time is allowed. All breaks, including unscheduled pauses and administrative or operational waiting periods during work, may be counted as rest time when additional rest allowance must be given because of high environmental temperatures. (V. Water and Sait Supplementation During the hot season or when the worker is exposed to ar tificially generated heat, drinking water shall be made available to the workers in such a way that they are stimulated to frequently drink small amounts, i.e., one cup every 15-20 minutes (about 150 ml or 1/4 pint). Tbe water1, shall be kept reasonably cool (10-15C or 50.0-60.0F) and shall be placed close to the workplace so that the worker can reach it without abandoning the work area. The workers should be encouraged to salt their food abun dantly during the hot season and particularly during hot spells. If the workers are unacdimatized, salted drinking water shall be made 7T ABDQei 36287 available in a concentration of 0.1% (1 gNaClto 1.0 liter or 1 level tablespoon of salt to 15 quarts of water). The added salt shall be completely dissolved before the water is distributed, and the water shall be kept reasonably cool. V. Other Considerations A. Clothing: The permissible heat exposure TLVs are valid for light summer clothing as customarily worn by workers when working under hot environmental conditions. If special clothing is required for performing a particular job and this clothing is heavier or it im pedes sweat evaporation or has higher insulation value, the wor ker's heat tolerance is reduced, and the permissible heat exposure limits indicated in Table 1 and Figure 1 are not applicable. For each job category where special clothing is required, the permissible heat exposure limit shall be established by an expert. B. Acclimatization and Fitness: Acclimatization to heat involves a series of physiological and psychological adjustments that occur in an individual during this first week of exposure to hot environ mental conditions. The-recommended heat stress TLVs are valid for acclimated workers who are physically fit. Extra caution must be employed when unacclimated or physically unfit workers must be exposed to heat stress conditions. References 1. Health Factors Involved in Working Under Conditions of Heat Stress. WHO Techni cal Report Series No. 412 (1969). 2. Dukes-Dobos, F.N. and A. Henschel: Development of Permissible Heat Exposure Limits for Occupational Work. ASHRAE Journal 75(9):57-62 (Sept. 1973). 3. Mlnard, D.: Prevention ofHeat Casualties in Marine Cops Recruits, Period of 195&6Q, with Comparative Incidence Rates and Climatic Heat Stresses in Other Training Categories. Research Report No. 4. Contract No. MR 005.01-0001.01, Naval Medi cal Research Institute, Bethesda, MD (Feb. 211961). Published in Military Medicine 126(44):261-272 (April 1961). 4. Mlnard, 0. and R.L O'Brien: Heat Casualties in the Navy and the Marine Corps 1959-1962 with Appendices on the Field Use of foe Wet-Bulb Globe Temperature Index. Research Report No. 7, Contract No. MR 005.01-0001.01. Naval Medical Research Institute. Bethesda. MD (March 12. 1964). 5. Astrand, Per-Olol and Kaare RodahJ: Textbook of Work Physiology. McGraw-Hill Book Co.. New York, San Francisco (1970). 6. Ergonomics Guide to Assessment of Metabolic and Cardiac Costs of Physical Work. Am. md. Hyg. Assoc. J. 32:560 (1971). 7. Energy Requirements for Physical Work. Research Progress Report No. 30. Purdue Farm Cardiac Project, Agricultural Experiment Station. West Lafayette, IN (1961). 8. Duniln, J.V.G.A. and R. Passmore: Energy, Work and Leisure. Heinemann Educa tional Books, Ltd., London (1967). 9. Lehmann, G.E., A. Muller and H. Spltzer Der Kaiorienbedarfe bte GewerbScher Arbeit Arbeitsphysiol. 74:166 (1950). `COLD STRESS These Threshold Limit Values (TLVs) are intended to pro tect workers from the severest effects of cold stress (hypothermia) and cold injury and to describe exposures to cold working con ditions under which it is believed that nearly all workers can be repeatedly exposed without adverse health effects. The TLV objective is to prevent the deep body core temperature from fall ing below 36C and to prevent cold injury to body extremities. Deep body temperature is the core temperature of the body as determined by rectal temperature measurements. For a single, occasional exposure to a cold environment a drop in core tem perature to no lower that 35C should be permitted. In addition to provisions for total body protection, the TLV objective is to pro tect all parts of the body with emphasis on hands, feet and head from cold injury. Introduction Fatal exposures to cold among workers have almost always resulted from accidental exposures involving failure to escape from low environmental air temperatures or from immersion in low temperature water. The single most important aspect of lifethreatening hypothermia is the fall in the deep core temperature of the body. The clinical presentations of victims of hypothermia are shown in Table 4 (taken from Dembert in AFP, January 1962). Workmen should be protected from exposure to cold so that the deep core temperature does not fall below 36C (96.6F); lower body temperatures will very likely result in reduced mental alert ness, reduction in rational decision making, or loss of conscious ness with the threat of fatal consequences. Pain in the extremities may be the first early warning of danger to cold stress. During exposure to cold, maximum severe shivering develops when the body temperature has fallen to 35C (95F). This must be taken as a sign of danger to the workers and exposure to cold should be immediately terminated for any workers when severe shivering becomes evident. Useful physical or mental work is limited when severe shivering occurs. Since prolonged exposure to cold air, or to immersion in cold water, at temperatures well above freezing can lead to danger ous hypothermia, whole body protection must be provided. 1. Adequate insulating clothing to maintain core temperatures above 36C must be provided to workers if work is performed in air temperatures below 4C (40F). Wind chill factor* or the cooling power of the air is a critical factor. The higher the wind speed and the lower the temperature in the work area, * 1986-1987 Adoption. * Wind chill factor is a unit of heat loss from a body defined in watts per meter squared per hour being a function of the air temperature and wind velocity upon the exposed body. t 72 73 TABLE 4 Progressive Clinical Presentations of Hypothermia* Core Temperature C F Clinical Signs 37.6 37 36 35 34 33 321 31 301 29 J 28 27 26 25 24 22 2lf 20 18 17 9 99.6 98.6 96.8 95.0 93.2 91.4 89.61 87.81 86.01 84.2) 82.4 80.6 78.8 77.0 75.2 71.61 69.81 68.0 64.4 62.6 48.2 "Normal" rectal temperature "Normal" oral temperature Metabolic rate increases in an attempt to com pensate for heat loss Maximum shivering Victim conscious and responsive, with normal blood pressure Severe hypothermia below this temperature Consciousness clouded; blood pressure becomes difficult to obtain; pupils dilated but react to light; shivering ceases Progressive loss of consciousness; muscular rigidity increases; pulse and blood pressure difficult to obtain; respiratory rate decreases Ventricular fibrillation possible with myocardial irritability Voluntary motion ceases; pupils nonreactive to light; deep tendon and superficial reflexes absent Victim seldom conscious Ventricular fibrillation may occur spon taneously Pulmonary edema Maximum risk of ventricular fibrilation Cardiac standstill Lowest accidental hypothermia victim to recover Isoelectric electroencephalogram Lowest artificially cooled hypothermia patient to recover * Presentations approximately related to core temperature. Reprinted from the January 1982 issue ofAmerican Family Physician; published by the American Academy of Family Physicians. 74 the greater the insulation value of the protective clothing re quired. An equivalent chill temperature chart relating the ac tual dry bulb air temperature and the wind velocity is presented in Table 5. The equivalent chill temperature should be used when estimating the combined cooling effect of wind and low air temperatures on exposed skin or when determining cloth ing insulation requirements to maintain the deep body core temperature. 2. Unless there are unusual or extenuating circumstances cold injury to other than hands, feet, and head is not likely to occur without the development of the initial signs of hypothermia. Older workers or workers with circulatory problems require special precautionary protection against cold injury. The use of extra insulating clothing and/or a reduction in the duration of the exposure period are among the special precautions which should be considered. The precautionary actions to be taken will depend upon the physical condition of the worker and should be determined with the advice of a physician with knowledge of the cold stress factors and the medical condi tion of the worker. Evaluation and Control For exposed skin, continuous exposure should not be per mitted when the air speed and temperature results in an equiva lent chill temperature of -32C (-25F). Superficial or deep local tissue freezing will occur only at temperatures below -1 C regard less of wind speed. At air temperatures of 2C (35.6F) or less it is imperative that workers who become immersed in water or whose clothing becomes wet be immediately provided a change of clothing and be treated for hypothermia. Recommended limits for property clothed workers for periods of work at temperatures below freezing are shown in Table 6. Special protection of the hands is required to maintain manual dexterity for the prevention accidents: 1. If fine work is to be performed with bare hands for more than 10-20 minutes in an environment below 16C (60F), special provisions should be established for keeping the workers' hands warm. For this purpose, warm air jets, radiant heaters (fuel burner or electric radiator), or contact warm plates may be utilized. Metal handles of tools and control bars shall be covered by thermal insulating material at temperatures be low -1C (30F). 2. If the air temperature falls below 16C (60F) for sedentary, 4C (40F) for light, -7C (20F) for moderate work and fine manual dexterity is not required then gloves shall be used by the workers. To prevent contact frostbite, the workers should wear anti contact gloves. 1. When cold surfaces below -7C (20F) are within reach, a 75 S JS U v> si S Es. h u o 3 oo m d -- Q m oo 1 7 7 v -- d ^v 777777 o ini r- ini maoooirtO'N ooi oi\ -- ---- n-- N-.-- iliii f1 r- o >n *0 ^ no 77 1 1 777700 5iOO-d" O 'O Wm Nt- N 00 00 00 O' OO O' O iiii o sO NO on r- O' d in 7Cl Cl i m NO r- r1 i in <7\ 7 7i 7 m i NO NO 1 o 00 -- 7 7Cl 1i m in ii o 00 in O' m r- 77 d 11ii NO | in o m 00 7i 1 i 7 i d o 1 9 r 00 00 NO dd V) 00 NO d 00 c- NO m 9ddd j;b J=mininin (3 - - N N rt ^ 76 ABDOO 1.36289 warning should be given to each worker by his supervisor to prevent inadvertent contact by bare skin. 2. It the air temperature is -17.5C (0F) or less, the hands should be protected by mittens. Machine controls and tools for use in cold conditions should be designed so that they can be handled without removing the mittens. Provisions for additional total body protection is required if work is performed in an environment at or below 4C (40F). The workers shall wear cold protective clothing appropriate for the level of cold and physical activity: 1. If the air velocity at the job site is increased by wind, draft, or artificial ventilating equipment, the cooling effect of the wind shall be reduced by shielding the work area, or by wearing an easily removable outer windbreak layer garment. Wind chill cooling rates are illustrated in Figure 2 and Table 7. 2. If only light work is involved and if the clothing on the worker may become wet on the job site, the outer layer of the cloth ing in use may be of a type impermeable to water. With more severe work under such conditions the outer layer should be water repellent, and the outerwear should be changed as it becomes wetted. The outer garments must include provisions for easy ventilation in order to prevent wetting of inner layers by sweat. If work is done at normal temperatures or in a hot environment before entering the cold area, the employee shall make sure that his clothing is not wet as a consequence of sweating. If his clothing is wet, the employee shall change into dry clothes before entering the cold area. The workers shall change socks and any removable felt insoles at regular daily intervals or use vapor barrier boots. The optimal fre quency ol change shall be determined empirically and will vary individually and according to the type of shoe worn and how much the individual's feet sweat. 3. If extremities, ears, toes and nose, cannot be protected suffi ciently to prevent sensation of excessive cold or frostbite by handware, footwear and face masks, these protective items shall be supplied in auxiliary heated versions. 4. If the available clothing does not give adequate protection to prevent hypothermia or frostbite, work shall be modified or suspended until adequate clothing is made available or until weather conditons improve. 5. Workers handling evaporative liquid (gasoline, alcohol or cleaning fluids) at air temperatures below 4C (40F) shall take special precautions to avoid soaking of clothing or gloves with the liquids because of the added danger of cold injury due to evaporative cooling. Special note should be taken of the particularly acute effects of splashes of "cryogenic fluids" or those liquids with a boiling point only just above ambient a temperatures. 77 79 TABLE 7 Wind Chill Cooling Rate Effects* Wind Chill Rates (Watts/m2/hr) Comments/Effects 700 1200 1400 1600 2300 2700 Conditions considered comfortable when dressed for skiing. Conditions no longer pleasant for outdoor activities on overcast days. Conditions no longer pleasant for outdoor activities on sunny days. Freezing of exposed skin begins for most people depending on the degree of activity and the amount of sunshine. Conditions for outdoor travel such as walking be come dangerous. Exposed areas of the face freeze in less than 1 minute for the average person. Exposed flesh will freeze within half a minute for the average person. (W o tts Per Squore M eter) * From Canadian Department ofthe Environment, Atmospheric Environ ment Service. Work-Warming Regimen If work is performed continuously in the cold at an equiva lent chill temperature (ECT) or below -7C (20F) heated warm ing shelters (tents, cabins, rest rooms, etc.) shall be made available nearby and the workers should be encouraged to use these shelters at regular intervals, the frequency depending on the severity of the environmental exposure. The onset of heavy shivering, frostnip, the feeling of excessive fatique, drowsiness, irritability, or euphoria, are indications for immediate return to the shelter. When entering the heated shelter the outerlayer of cloth ing shall be removed and the remainder of the clothing loosened to permit sweat evaporation or a change of dry work clothing provided. A change of dry work clothing shall be provided as necessary to prevent workers from returning to their work with wet clothing. Dehydration, or the loss of body fluids, occurs insidiously in the cold environment and may increase the sus ceptibility of the worker to cold injury due to a significant change in blood flow to the extremities. Warm sweet drinks and soups should be provided at the work site to provide caloric intake and fluid volume. The intake of coffee should be limited because of a diuretic and circulatory effect. 80 81 For work practices at or below -12C (10F) ECT the fol lowing shall apply: 1. The worker shall be under constant protective observation (buddy system or supervision). 2. The work rate should not be so high as to cause heavy sweat ing that will result in wet clothing; if heavy work must be done, rest periods must be taken in heated shelters and opportunity for changing into dry clothing shall be provided. 3. New employees shall not be required to workfull-time in cold in the first days until they become accustomed to the work ing conditions and required protective clothing. 4. The weight and bulkiness of clothing shall be included in estimating the required work performance and weights to be lifted by the worker. 5. The work shall be arranged in such a way that sitting still or standing still for long periods is minimized. Unprotected metal chair seats shall not be used. The worker should be protected from drafts to the greatest extent possible. 6. The workers shall be instructed in safety and health pro cedures. The training program shall include as a minimum instruction in: a. Proper rewarming procedures and appropriate first aid treatment. b. Proper clothing practices. c. Proper eating and drinking habits. d. Recognition of impending frostbite. e. Recognition signs and symptoms of impending hypo thermia or excessive cooling of the body even when shiver ing does not occur. f. Safe work practices. Special Workplace Recommendations Special design requirements for refrigerator rooms include the following: 1. In refrigerator rooms, the air velocity should be minimized as much as possible and should not exceed 1 meter/sec (200 fpm) at the job site. This can be achieved by property designed air distribution systems. 2. Special wind protective clothing shall be provided based upon existing air velocities to which workers are exposed. Special caution shall be exercised when working with toxic substances and when workers are exposed to vibration. Cold exposure may require reduced exposure limits.' Eye protection for workers employed out-of-doors in a snow and/or ice-covered terrain shall be supplied. Special safety goggles to protect against ultraviolet light and glare (which can 82 produce temporary conjuntivitls and/or temporary loss of vision) and blowing ice crystals are required when there is an expanse of snow coverage causing a potential eye exposure hazard. Workplace monitoring is required as follows: 1. Suitable thermometry should be arranged at any workplace where the environmental temperature is below 16C (60F) to enable overall compliance with the requirements of the TLV to be maintained. 2. Whenever the ajrtemperature at a workplace falls below -1 C (30F), the dry bulb temperature should be measured and recorded at least every 4 hours. 3. In indoor workplaces, the wind speed should also be recorded at least every 4 hours whenever the rate of air movement exceeds 2 meters per second (5 mph). 4. In outdoor work situations, the windspeed should be measured and recorded together with the air temperature whenever the air temperature is below -1C (30F). 5. The equivalent chill temperature shall be obtained from Table 16 in all cases where air movement measurements are re quired, and shall be recorded with the other data whenever the equivalent chill temperature is below -7C (20F). Employees shall be excluded from work in cold at -1C (30F) or below if they are suffering from diseases or taking medi cation which interferes with normal body temperature regulation or reduces tolerance to work in cold environments. Workers who are routinely exposed to temperatures below -24C (-10F) with wind speeds less than five miles per hour, or air tempeatures below -18C (0F) with wind speeds above five miles per hour should be medically certified as suitable for such exposures. Trauma sustained in freezing or subzero conditions requires special attention because an injured worker is predisposed to secondary cold injury. Special provisions must be made to pre vent hypothermia and secondary freezing of damaged tissues in addition to providing for first aid treatment. *HAND-ARM (SEGMENTAL) VIBRATION These Threshold Limit Values (Table 8) refer to component accelerations levels and durations of exposure that represent con ditions under which it is believed that most workers may be exposed repeatedly without progressing beyond Stage 3 of the TaylorPelmear Classification System for Vibration-induced White Finger (VWF), also known as Raynaud's Phenomenon of Occupational Origin). Since there is a paucity of dose-response relationships for VWF, these recommendations have been derived from epidemio logical data from forestry, mining, and metal working. These values* * 1986-1987 Adoption. 83 should be used as guides in the control of hand-arm vibration ex posure and because of individual susceptibility, should not be regarded as defining a boundary between safe and dangerous levels. It should be recognized that the application of the TLV alone for hand-arm vibration will not protect ail workers from the adverse effects of hand-arm vibration exposure. The use of: 1) antivibration tools, 2) antivibration gloves, 3) proper work practices which keep the worker's hands and remaining body warm and also minimize the vibration coupling between the worker and the vibration tool are necessary to minimize vibration exposure, and 4) a conscien* ciously applied medical surveillance program are ALL necessary to rid VWF from the workplace. Continuous, Intermittent, Impulsive, or Impact Hand-arm Vibration The measurement of vibration should be performed in accordance with the procedures and instrumentation specified by the Second Draft International Standard ISO/DIS 5349 (1984), Guide for the Measurement and the Assessment of Human Exposure to Vibration Transmitted to the Hand, and summarized below: The acceleration of a vibration handle or work piece should be determined in three mutually orthogonal directions at a point dose to where vibration enters the hand. The directions shall prefer ably be those forming the ISO biodynamic coordinate system, but may be a closely related basicentric system with its origin at the interface between the hand and the vibrating surface (see'Figure 3) to accommodate different handle or work piece configurations. A small and lightweight transducer shall be mounted so as to record accurately one or more orthogonal components of the source vibra tion in the frequency range from 5 to 1500 Hz. Each component should be frequency-weighted by a filter network with gain charac teristics specified by the ISO for human-response vibration meas- 3 1/3 OCTAVE-8AN0 CENTRE FREOUENCY iHi) Figure 4--Gain characteristics of the filter network used to frequencyweight acceleration components (continuous line). The filter tolerances (dashed lines) are provisional, and are those contained in ISO 5349. uring instrumentation, to account for the change in vibration hazard with frequency (see Figure 4). Assessment of vibration exposure should be made for EACH applicable direction (X* Yh, ZJ since vibration is a vector quanti ty (magnitude and direction). In each direction, the magnitude of the vibration during normal operation of the power tool, machine or work piece shall be expressed by the root-mean-square (rms) value of the frequency-weighted component accelerations, in units of meters per second squared (m/s2), or gravitational units (g), the largest of which, a*, forms the basis for exposure assessment. For each direction being measured, linear integration shall be employed for vibrations that are of extremely short duration or vary substantially in time. If the total daily vibration exposure in a given direction is composed of several exposures at different rms ac celerations, then the equivalent, frequency-weighted component acceleration in that direction shall be determined in accordance with the following equation: Flgure 3--Biodynamic and basicentric coordinate systems for the hand, showing the directions of the acceleration components (ISO 5349). 84 85 ABDOO136294 n where: T = Xt( i= 1 T = total daily exposure duration aK = ith frequency-weighted, rms acceleration ' component with duration T, These computations may be performed by commercially avail able human-response vibration measuring instruments. TABLE 8 Threshold Limit Values for Exposure of the Hand to Vibration in Either X*, Yh, Zh Directions Total Daily Exposure Duration* Values of the Dominant,b Frequency-Weighted, rms. Component Acceleration Which Shall not be Exceeded 4 hours and less than 8 2 hours and less than 4 1 hour and less than 2 less than 1 hour m/s2 4 6 8 12 g* 0.40 0.61 0.81 1.22 The total time vibration enters the hand per day, whether continuously or intermittently. b Usually one axis of vibration is dominant over the remaining two axis. If one or more vibration axis exceeds the Total Daily Exposure then the TLV has been exceeded. * g * 9.81 m/s2. i! Notes: Table 8: I I 1. Hardly any person exposed at or below the TLVs for vibraI' i tion contained in Table 8 has progressed to Stage 3 Vibra- , tion White Finger, in the Tayior-Pelmear classification, i.e., | I the point at which extension blanching of all fingers has ! occurred and there is definite Interference at work, home, and I; restricted social activities.!2-7) 2. Acute exposures to frequency-weighted, rms, component ! accelerations in excess of the TLVs for infrequent periods of time (e.g., 1 day per week, or several days over a two-week I period) are not necessarily more harmful.!24' ! 86 3. Acute exposures to frequency-weighted, rms, component accelerations of three times the magnitude of the TLVs are expected to resuft in the same health effects after between 5 and 6 years of exposure.!24) 4. Preventive measures, including specialized preemployment and annual medical examinations to identify persons suscept ible to vibration, should be implemented in situations in which workers are or will be exposed to hand-arm vibration .P-h 5. To moderate the adverse effects of vibration exposure, workers should be advised to avoid continuous vibration exposure by cessation of vibration exposure for approximately 10 minutes per continuous vibration hour. 6. Good work practices should be used, and should include in structing workers to employ a minimum hand grip force con sistent with safe operation of the power tool or process, keep their body and hands warm and dry, and avoid smoking.*2-3) 7. A transducer and its device for attachment to the vibrating source suitable for measurement purposes together should weigh less than 15 grams, and should possess a cross-axis sensitivity of less than 10%. 8. The measurement by many (mechanically underdamped) piezoelectric accelerometers of repetitive, large displacement, impulsive vibrations, such as those produced by percussive pneumatic tools, is subject to error. The insertion of a suit able, low-pass, mechanical filter between the accelerometer and the source of vibration with a cut-off frequency of 1500 Hz or greater (and cross-axis sensitivity of less than 10%) can help eliminate incorrect readings.!2-*) 9. The manufacturer and type number of all apparatus used to measure vibration should be reported, as well as the value of the dominant direction and frequency-weighted, rms, com ponent acceleration. References 1. Pyytto I.: Vibration Syndrome. A Review. Vibration and Work, pp. 1-24. 0. Dortionen. Ed. Institute of Occupational Health. Helsinki (1976). 2. Vibration Whits Finger in Industry, W. Taylor and P.L. Pelmear, Eds. Academic Press, London (1975). 3. NIQSH: Proceedings ot the International Occupational Hand-Arm Vibration Con ference, D.E. Wasserman and W. Taytor, Eds. 0HEW NIQSH Pub. No. 77-170 (1977). 4. Brammar, JJ.: Threshold Limit for Hand-Arm Vibration Exposure Throughout the Workday. Vibration Effects on die Handand Arm In Industry, pp. 29U301. A.J. Brammer and W. Taylor, Eds. John Wiley & Sons, New York (1982). 5. Wasserman, O.E. and W. Teytor. Environmental and Occupational Medicine, Chap. 68, Occupational Vibration, pp. 743-749. W.N. Rom, Ed. Little, Brown and Co., Boston (1982). 8. NIOSH: CurrentIntelligenceBulletin #38: Vibration Syndrome. DHHS (NIOSH) pub. No. 83-110 (1963). 7. NIOSH: Vibration Syndrome. NIOSH Videotape #177 (27 minutes). Cincinnati, OH. 87 ABD00136295 9. International Organization lor Standardization: Guide for the Measurement and the Assessment of Human Exposure to Vibration Transmitted to the Hand. Second OIS 5349. International Organization for Standardization, Geneva (in press, 1983). 9. International Organization for Standardization: Human-Response Vibration Mea suring Instrumentation. Second Draft Proposal DP 8041. ISO/TC108/SC 3 n 99. International Organization for Standardization, Geneva (unpublished, 1982). IONIZING RADIATION The Committee accepts the philosophy and recommendations of the National Council on Radiation Protection and Measurements (NCRP) for the ionizing radiation TLV. The NCRP is charted by Congress to, in part, collect analyze, develop and disseminate in formation and recommendations about protection against radiation and about radiation measurements, quantities and units, includ ing development of basic concepts in these areas. NCRP Report No. 39 provides basic philosophy and concepts leading to protec tion criteria established in the same report.*1) Other NCRP reports address specific areas of radiation protection and, collectively, pro vide an excellent basis for establishing a sound program for radi ation control. The Committee recommends the listed references as substantative documentation of a sound basis for ionizing radi ation protection. The Committee also strongly recommends that all exposure to ionizing radiation be Kept as low as reasonably achievable within the stated guidance. References t. Basic Radiation Protection Criteria. NCRP Report No. 39 (January 15,1971). 2. Maximum Permissible Body Burdens and Maximum Permissible Concentrations of Radionuclides in Airand in Water for OccupationalExposure. National Bureau of Stan dards Handbook 69, (June 5, 1959), with Addendum 1 (August 1963). Available as NCRP Report No. 22. The above documents, as well as information on numerous other NCRP Reports addressing specific subjects in ionizing radiation protection, are available from: NCRP Publications, 7910 Woodmont Ave., Suite 1016, Bethesda, MD 20614. TABLE 9 Limiting Angle to Extended Source Which May Be Used For Applying Extended Source TLVs l' l Exposure Duration(s) Exposure Duration^) Angle a (mrad) 10- 8.0 10- 5.4 1(H 3.7 10* 2.5 10* 1.7 10-* 2.2 10* 3.6 10-2 5.7 10-' 9.2 1.0 15 10 24 102 24 103 24 10* 24 TLVs for the eye in the spectral range of 400-1400 nm, which should be averaged over a 7 mm limiting aperture (pupil); and except for all TLVs for wavelengths between 0.1-1 mm where the limiting aperture is 10 mm. No modification of the TLVs is per mitted for pupil sizes less than 7 mm. The TLVs for "extended sources" apply to sources which subtend an angle greater than a (Table 9) which varies with ex posure time. This angle is not the beam divergence of the source. Correction Factors A and B (CA and Cg) The TLVs for ocular exposure in Tables 10 and 11 are to be used as given for all wavelength ranges. The TLVs for wavelengths between 700 nm and 1049 nm are to be increased by a uniformly extrapolated factor (C*) as shown in Figure 5. Be- LASERS The Threshold Limit Values (TLVs) are for exposure to laser radiation under conditions to which nearly all workers may be exposed without adverse effects. The values should be used as guides in the control of exposures and should not be regarded as fine lines between safe and dangerous levels. They are based on the best available information from experimental studies. Limiting Apertures The TLVs expressed as radiant exposure or irradiance in this section may be averaged over an aperture of 1 mm except for 68 Figure 5--TLV correction factor for A = 700-1400 nm.* (* For A = 700-1049 nm, C* = 10M-*W; For A = 1050-1400 nm, CA= 5.) 89 ABD0M36296 tween 1049 nm and 1400 nm, the TLV has been increased by a factor (C*) of five. For certain exposure times at wavelengths ii between 550 nm and 700 nm, correction factor (Ca) must be applied. The TLVs for skin exposure are given in Table 12. The TLVs are to be increased by a factor (C*) as shown in Figure 5 for wavelengths between 700 nm and 1400 nm. To aid in the deter mination of TLVs for exposure durations requiring calculations of fractional powers Figures 6, 7 and 8 may be used. * Repetitively Pulsed Exposures Scanned CW lasers or repetitively pulsed lasers can both produce repetitively pulsed exposure conditions. The TLV for intrabeam viewing which is applicable to wavelengths between 400 and 1400 nm and a single-pulse exposure (of pulse duration f) is modified in this instance by a correction factor determined by the number of pulses in the exposure. First, calculate the num ber of pulses (n) in an expected exposure situation; this is the pulse repetitition frequency (PRF in Hz) multiplied by the dura tion of exposure. Normally, realistic exposures may range from 0.25s for a bright visible source to 10s for an infrared source. The corrected TLV on a per-pulse basis is: TLV = (n-u) (TLV for single-pulse) (1) This approach applies only to thermal-injury conditions, i.e., all exposures at wavelengths greater than 700 nm, and for many exposures at shorter wavelengths. For wavelengths less than or equal to 700 nm, the corrected TLV from equation 1 above applies if the average irradiance does not exceed the TLV for continu ous exposure. The average irradiance (i.e., the total accumulated exposure for nt seconds) shall not exceed the radiant exposure given in Table 10 for exposure durations of 10 seconds to T,. Figure 6a--TLV for intrabeam (direct) viewing of laser beam (400-700 nm). 1986-1987 Addition. 90 EXPOSURE OURATION Is) Figure 6b--TLV for intrabeam (direct) viewing of CW laser beam (400-1400 nm). 91 ABDOO136297 Figure 7a--TLV tor laser exposure of skin and eyes for far-infrared radi ation (wave-lengths greater than 1.4 ^m). Figure 8a--TLV for extended sources or diffuse reflections of laser radi ation (400-700 nm). Figure 7b--TLV for CW laser exposure of skin and eyes for far-infrared radiation (wave-lengths greater than 1.4 ^m). 92 Figure 8b--TLV for extended sources or diffuse reflections of laser radi ations (400-1400 nm). 93 StJ-.SS s e! fL re e _h- 0-3 0 * E Xo " O X 40 i-- in 03 CO x o *>? 7- o 0o x r0 'x"" OO- :rs 1 oo 1 o I o n o cE CE Ee Ee cE OO-^-T-Tj- o a^ o - *- o rE cE sc ee "E e coo c o o to m o. oo o oo (-- N. i- *- h- ftl* --5 I * CO 1-0 0 X 0 on ** t- o 1 i *-' ooo E 4: E 4 s t-. 3 0 II c 2g ? M*g 'k~ I ON O --8% x - i is . 0=5 >" f9t3 ^E T033 CS C % o/ >*1 ^.^2 5^ So 7B * II 1 o ,g III ^*? I g .S 5 -!* .9 ii 93 >8 W5 -J gH ES * 5^x ft ^ 09 V> ree CCa?t<=-> ^W _E 3c __ 05 .8 m^ MS 5 Si 81 g figef CO C9 S gc#" re o S'o S * S ft S .g " -o "S ^ o 09 w 9 J= g aO ;JS < CD cr QC i'-f. 95 ADDOOlttaOO ii 'l T A B L E 11 Threshold L im it Values fo r Viewing a Diffuse Reflection o f a Laser Beam o r an Extended Source Laser Light IR-A E5 - l E - k-- EL - flIri[S_ l 1- CO ^ wcvj l"94>* O i-o i--S 8 o E <53 1-8 He ii x W x CO 2 o oh" I r ss of o o o o -o ox *2 o o CO r-ots o oo CO p >es 13 s i It c E EEEEE = c c S o o> o o o 0^0 S <0 N of or*- o poo p P EE ooV oo oo'T E 4 & Ec Ec Ec EC Ec Ec ooCM oOwOomIOomIoOvOo Ec Ec Ec oor-- oor*. oof-- E o- o eO CD > 3 CC 96 ei '--o. 5Eo 2 5 L |oC -9 h- g hc3 x t <8 o .O O o> JO~CM ECQ Mi-- OW V If llC/5 iXs a I- O eXoo5l =o^ - x o o on ?? V 2 OOOo E o. . 4 -& 22 EE cc oo SCM<=>- : 1 it o eO oO *z < < m 3 3 S- 97 ABDOW 36300 NOISE These Threshold Limit Values (TLVs) refer to sound pres sure levels and durations of exposure that represent conditions under which it is believed that nearly all workers may be repeat edly exposed without adverse effect on their ability to hear and understand normal speech. Prior to 1979, the medical profession had defined hearing impairment as an average hearing threshold level in excess of 25 decibels (ANSI-S3.6-1969) at 500,1000, and 2000 Hz, and the limits which are given have been established to prevent a hearing loss in excess of this level.w The values should be used as guides in the control of noise exposure and, due to individual susceptibility, should not be regarded as fine lines between safe and dangerous levels. It should be recognized that the application of the TLV for noise will not protect all workers from the adverse effects of noise exposure. A hearing conservation program with audiometric test ing is necessary when workers are exposed to noise at or above the TLV levels. Continuous or Intermittent The sound level shall be determined by a sound level meter, conforming as a minimum to the requirements of the American National Standard Specification for Sound Level Meters, SI .4 (1971) Type S2A, and set to use the A-weighted network with slow meter response. Duration of exposure shall not exceed that shown in Table 13. These values apply to total duration of exposure per work ing day regardless of whether this is one continuous exposure or a number of short-term exposures and does include the im pact and impulsive type of noise that contributes to the sound level meter reading at slow response. When the daily noise exposure is composed of two or more periods of noise exposure of different levels, their combined effect should be considered, rather than the individual effect of each. If the sum of the following fractions: exceeds unity, then, the mixed exposure should be considered to exceed the threshold limit value, C, indicates the total dura tion of exposure at a specific noise level, and T, indicates the total duration of exposure permitted at that level. All on-the-job noise exposures of 80 dBA or greater shall be used in the above calculations. * In 1979 the American Academy of Ophthalmology and Otolaryngology (AAOO) included 3000 Hz in their hearing impairment formula. 98 TABLE 13 Threshold Limit Values for Noise Duration per Day Hours Sound Level dBA| 16 80 8 85 4 90 2 95 1 100 1/2 105 1/4 no 1/8 115* f Sound level in decibels are measured on a sound level meter, con forming as a minimum to the requirements of the American National Standard Specification for Sound Level Meters, SI .4 (1971) Type S2A, and set to use the A-weighted network with slow meter response. * No exposure to continuous or intermittent in excess of 115 dBA. Impulsive or Impact It is recommended that exposure to impulsive or impact noise shall not exceed the limits listed in Table 14 or taken from Figure 9. No exposures in excess of 140 decibels peak sound pres sure level are permitted. Impulsive or impact noise is considered to be those variations in noise levels that involve maxima at in tervals of greater than one per second. Where the intervals are less than one second, it should be considered continuous. TABLE 14 Threshold Limit Values Impulsive or Impact Noise Sound Level dB* 140 130 120 Permitted Number of Impulses or Impacts per day 100 1000 10,000 * Decibels peak sound pressure level; re 20 jzPa. 99 ? ABDOO 36301 i! t * (i: Rgure 9--Threshold Limit Values for Impulse/Impact Noise. i i RADIOFREQUENCY/MICROWAVE RADIATION These Threshold Limit Values (TLVs) refer to radiofrequency (RF) and microwave radiation in the frequency range from 10 kHz to 300 GHz, and represent conditions under which it is believed workers may be repeatedly exposed without adverse health effects. The TLVs shown in Table 15 are selected to limit the aver* age whole body specific absorption rate (SAR) to 0.4 W/kg in any six-minute (0.1 hr) period for 3 MHz to 300 GHz, see Figure 10. Between 10 kHz and 3 MHz the average whole body SAR is still limited to 0.4 W/kg, but the plateau at 100 mW/cm2 was set to protect against shock and burn hazards. Since it is usually impractical to measure the SAR, the TLVs are expressed in units that are measurable, viz, squares of the electric and magnetic field strength, averaged over any 0.1 hour period. This can be expressed in units of equivalent plane wave power density for convenience. The electric field strength (E) squared, magnetic field strength (H) squared, and power density (PD) values are shown in Table 15. For near field exposures PD cannot be measured directly, but equivalent plane wave power density can be calculated from the field strength measurement data as follows: 100 101 Rgure 1 0-- Threshold Lim it Values (TLV) for Radiofrequency/Microwave Radiation in the workplace (whole body SAR less than 0.4 W/kg). i ADDOD130302 .1 j| PD in mW/cirf - 1 whore: E2 is in volts squared (V2) per meter squared (m2). PD in mW/cm2 = 37.7 H2 '4 where: ! H2 is in amperes squared (A2) per meter squared (m2). . 1 These values should be used as guides in the evaluation and 11 control of exposure to radiofrequency/microwave radiation, and 1 should not be regarded as a fine line between safe and dangerous levels. " Notes: ! I 1. Needless exposure to all Radiofrequency Radiation (RFR) ex- posures should be avoided given the current state of ] knowledge on human effects, particularly non-thermal effects. 1 2. For fields consisting of a number of frequencies, the fraction | of the protection guide incurred within each frequency level I should be determined and the sum of all fractions should not 1 exceed unity. I 3. For pulsed and continuous wave fields, the power density is | averaged over the six-minute period. HI 4. For partial body exposures at frequencies between 10 kHz I and 1.0 GHz, the protection guides in Table 15 may be exm ceeded if the output power of a radiating device is 7 watts 1 or less. For example, if a hand held transmitter operating at I 27 MHz has a maximum output of 5 watts, it would be excluded I from any further field measurements. |l 5. The TLVs in Table 15 may be exceeded if the exposure conI ditions can be demonstrated to produce a SAR of less than I 0.4 W/kg as averaged over the whole body and spatial peak I SAR values less than 8.0 W/kg as averaged over any 1.0 gram I of tissue. For example, for frequencies from 3 to 30 MHz, the it equivalent power density can be increased by a factor of 10 1 up to a limit of 100 mW/cm2, if it can be assured that ex1 posed individuals are not in contact with the ground plate. 1 | 6. At frequencies below 30 MHz, ungrounded objects such as 1 vehicles, fences, etc., can strongly couple to RF fields. For I field strengths near the TLV, shock and burn hazards can I exist. Care should be taken to eliminate ungrounded objects, | to ground such objects, or use insulated gloves when un grounded objects must be handled. | 7. No measurement should be made within 5 cm of any object. | 8. All exposures should be limited to a maximum (peak) electric | ; field intensity of 100 kV/m. ! 102 s H C- 8 X X In s 8 03 P; rIVTC) s 8 fO (N 1 a JS 8 mpn PSJ ee $1 U O u *S 03 > swrnr-- onrr-- notr- orrn--. rr-t* a = o N XX s 2 cn z 3222 o oo 103 * f = frequency in MHz. i ADDQ0466303 ULTRAVIOLET RADIATION* These Threshold Limit VaJues (TLVs) refer to ultraviolet radi ation in the spectral region between 200 and 400 nm and represent conditions under which it is believed that nearly ali workers may be repeatedly exposed without adverse effect. These values for exposure of the eye or the skin apply to ultraviolet radiation from arcs, gas and vapor discharges, fluorescent and incandescent sources, and solar radiation, but do not apply to ultraviolet lasers.* These values do not apply to ultraviolet radi ation exposure of photosenitive individuals or of individuals con comitantly exposed to photosensitizing agents.'1' These values should be used as guides in the control of exposure to contin uous sources where the exposure duration shall not be less than 0. 1.sec. These values should be used as guides in the control of exposure to ultraviolet sources and should not be regarded as a fine line between safe and dangerous levels. \ Recommended Values The threshold limit value for occupational exposure to ultraviolet radiation incident upon skin or eye where irradiance values are known and exposure time is controlled are as follows: 1. For the near ultraviolet spectral region (320 to 400 nm) total irradiance incident upon the unprotected skin or eye should not exceed 1 mW/cm2 for periods greater than 103 *s*e*c*o*n*d1s0 (approximately 16 minutes) and for exposure times less than tO3 seconds should not exceed one J/cm2. 2. For the actinic ultraviolet spectral region (200-315 nm), radiant exposure incident upon the unprotected skin or eye should not exceed the values given in Table 16 within an 8-hour period. 3. To determine the effective irradiance of a broadband source weighted against the peak of the spectral effectiveness curve (270 nm), the following weighting formula should be used: where: Erfr = ^ Si AA = effective irradiance relative to a monochromatic source at 270 nm in W/cm2 (J/s/cm2) Ej = spectral irradiance in W/cmz/nm S, = relative spectral effectiveness (unitless) AA = band width in nanometers 4. Permissible exposure time in seconds for exposure to actinic ultraviolet radiation incident upon the unprotected skin or eye may be computed by dividing 0.003 J/cm2 by E*, in W/cm2. * See Laser TLVs. 104 TABLE 16 Relative Spectrial Effectiveness by Wavelength* Wavelength (nm) TLV (mj/cm2) Relative Spectral Effectiveness s> 200 100 210 40 220 25 230 16 240 10 250 7.0 254 6.0 260 4.6 270 3.0 280 3.4 290 4.7 300 10 305 50 310 200 315 1000 0.03 0.075 0.12 0.19 0.30 0.43 0.5 0.65 1.0 0.88 0.64 0.30 0.06 0.015 0.003 * See Laser TLVs. TABLE 17 Permissible Ultraviolet Exposures Duration of Exposure _______Per Day Effective Irradiance, E*, (yW/cmJ) 8 hrs........................ 0.1 4 hr............................... 0.2 2 hrs............................................... 0.4 1 hr .................................................... 0.8 30 min............................................... 1.7 15 min............................................... 3.3 10 min............................................... 5 5 min.................................................. 10 1 min.................................................. 50 30 sec.................................................. 100 10 sec.................................................. 300 1 sec.................................................... 3,000 0.5 sec............................................... 6,000 0.1 sec............................................... 30,000 105 ?0O 220 240 2(0 2 U 300 320 WAVE LENGTH (NANOMETERS] 340 Figure 11--Threshold Limit Values for Ultraviolet Radiation. The exposure time may also be determined using Table 17 which provides exposure times corresponding to effective irradiances in fiW/cm2. 5. All the preceding TLVs for ultraviolet energy apply to sources which subtend an angle less than 80. Sources which sub tend a greater angle need to be measured only over an angle of 80. Conditioned (tanned) individuals can tolerate skin exposure in excess of the TLV without erythemal effects. However, such conditioning may not protect persons against cancer. Reference 1. Sunlight and Man. Fitzpatrick at al, Eds. Univ. of Tokyo Press, Tokyo, Japan (1974). NOTICE OF INTENDED CHANGES (for 1986*87) These physical agents, with their corresponding values, comprise those for which either a limit has been proposed for the first time, or for which a change in the "Adopted" listing has been proposed. In both cases, the proposed limits should be considered trial limits that will remain in the listing for a period of at least one year. If after one year no evidence comes to light that questions the appropriateness of the values herein the values will be recon sidered for the the "Adopted" list. NOTICE OF INTENT TO ESTABLISH THRESHOLD LIMIT VALUES LIGHT AND NEAR-INFRARED RADIATION These Threshold Limit Values (TLVs) refer to visible and nearinfrared radiaton in the wavelength range of 400 nm to 1400 nm and represent conditions under which it is believed that nearty all workers may be exposed without adverse effect. These values should be used as guides in the control of exposure to light and should not be regarded as a fine line between safe and dangerous levels. Recommended Values The Threshold Limit Value for occupational exposure to broad-band light and near-infrared radiation for the eye apply to exposure in any eight-hour workday and require knowledge of the spectral radiance (LJ and total irradiance (E) of the source as measured at the position(s) of the eye of the worker. Such detailed spectral data of a white light source is generally only required if the luminance of the source exceeds 1 cd cm-2. At luminances less than this value the TLV would not be exceeded. The TLVs are: 1. To protect against retinal thermal injury, the spectral radiance of the lamp weighted against the function R (Table 18) should not exceed: moo >A U K2 AA < 1/at 400 (1)* * Formulae (1) and (7) are empirical and are not strictly speaking, dimensionally correct. To make the formulae dimensionally correct, one would have to insert a dimensional correction factor k in the right hand numerator in each formula. For formula (1) this would be k, 1 W rad sVfe/fcm2 sr). and for formula (7) Kj = 1 W rad/Jcm2 sr). 107