Document rxMVEMZ03gmkNBg3mpoOR6X67

Adopted by ACG/H for 1974 Threshold Limit Values Chemical Substances in Workroom Air It is incumbent upon the safety professional to have available and use the most current advice and guidelines for controlling and mini mizing the risk to employees of ex posures to chemical and physical agents. Threshold limit value refers to air-borne concentrations of sub stances, and it represents conditions under which it is believed nearly all workers may be repeatedly exposed day-after-day without adverse effect. Because of a wide variation in indi vidual susceptibility, however, a small percentage of workers may experience discomfort 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 limit values refer to time-weighted concentrations for a seven or eight-hour work-day and 40-hour work-week. They should be used as guides in the control of health hazards and should not be used as fine lines between safe and dangerous concentrations. Threshold limits are based on the best available information from: in dustrial experience; experimental human and animal studies; a com bination of these when possible. The basis on which the values are estab lished may differ from substance to substance; protection against im pairment of health may be a guid ing factor for some, whereas reason able freedom from irritation, narco sis, nuisance, or other forms of stress may form the basis for others. As the amount and nature of the information available for establish- Editor's Note: NSNews will publish be Threshold Limit Values for Phy- '1 Agents in the Workroom Envint in the November 1974 issue. 1974, NATIONAL SAFETY NEWS ing a TLV varies from substance to substance, consequently the preci sion of the estimated TLV also var ies. Consult the latest Documenta tion to assess the extent of the data available for a given substance. The Air-Borne Contaminants Committee of ACGIH holds to the opinion that limits based on physical irritation should be considered no less binding than those based on physical impairment. There is in creasing evidence that physical irri tation may initiate, promote, or ac celerate physical impairment through interaction with other chemical or biologic agents. In spite of the fact that serious injury is not believed likely as a result of exposure to concentration of a substance at the threshold limit, the best practice is to maintain con centrations of all atmospheric con taminants as low as is practical. TLV's are intended for use in the practice of industrial hygiene and should be interpreted and applied only by a person trained in this dis cipline. They are not intended for use, or for modification for use, as a relative index of hazard, in the evaluation of air pollution nuisances, in estimating the toxic potential of continuous, uninterrupted exposures, as proof or disproof of an existing disease or physical condition, or for the adoption by countries whose working conditions difEer from those in the U.S. and where substances and processes differ. Specific statements on the toxicity and hazard, culled from the litera ture, or from the collective experi ence of the TLV Committee mem bers, have been referenced for fur ther examination and a clear, sum marizing statement on precisely what basis the TLV has been se lected is included in most documen tations. This latter has been felt by the committee to be a highly im portant adjunct for industrial hy gienists administering the TLV's. it.3. TLVvAir-Bomej,Contaminants 'paoi'-EMcapion;; P^mSIh: ^Herbe/^EIkin^pSU)^: `f.W. G. Fredrick, SeJ>.-\y '" Bernard Grabois, P.E. a .Paul Gross, M.D. - John W. Knauber, M.P.H. Jesse Lieberman, P.E, Keith R./Long, M.D.V.. T Fredericic^T.'-McDennolt, P.E. ,5- E. Mastromotteo, Waiter^W. Melvin, Jr.; J&lt. CoK<Marshall -Steinberg, __ ftWma^Wagn^Recording' Secretary,^ .^UaisonT'Members,, Davidr;^`AXI$TPv:a*d d e'n;7tabor?Un ionss&Ste Copyright 1974 by American Confer ence of Governmental Industrial Hy gienists. The American Conference of Govern mental Industrial Hygienists will wel come requests for permission to repub lish or reprint these Threshold Limit Values. Requests for such permission should be directed to the Secretary-Trea surer, Box 1937, Cincinnati 45201. Price Each 1-49 ........................................................ 154 50-200 .......................................... 654 Quantities over 200, prices upon request. Documentation of the Threshold Limit Values for Substances in Workroom Air. A separate companion piece to the Chemical TLVs is issued under this title. This publication gives the pertinent scientific information and data with reference to literature sources that were used to base each limit. Each documen tation also contains a statement defining the type of response against which the limit is safe-guarding the worker. For a better understanding of the TLV's it is essential that the Documentation be con sulted with the TLVs being used. Information concerning the availabil ity of copies of the Documentation of the Threshold Limit Values for Substances in Workroom Air' should be directed to the Secretary-Treasurer, ACGIH. Editor's Note: TLVs for chemical substances are listed (as they appear in the ACGIH publication) on the following pages -- six ACGIH pages to one NSNews page, and ACGIH publication page numbers are shown. 409972 0419 95 PREFACE CHEMICAL CONTAMINANTS Threshold limit values refer to airborne concentrations of substances and represent conditions under which it is believed that nearly all workers may be repeatedly exposed day after day without adverse effect. Be cause of wide variation in individual suscep tibility, however, a small percentage of workers may experience discomfort from some substances at concentrations at or below the threshold limit, a smaller per centage may be affected more seriously by aggravation of a pre-existing condition or by development of an occupational illness. Simple tests are now available (J. Occup. Med. 9: 537, 1967; Ann. N.Y. Acad. Sci., 151, Art. : 968, 1968) that may be used to detect those individuals hypersusceptible to a variety of industrial chemicals (respira tory irritants, hemolytic chemicals, organic isocyanates, carbon disulfide). These tests may be used to screen out by appropriate job placement the hyperreactive worker and thus in effect improve the "coverage" of the TLVs. Threshold limit values refer to timeweighted concentrations for a 7 or 8-hour workday and 40-hour workweek. They should be used as guides in the control of health hazards and should not be used as fine lines between safe and dangerous con centrations. (Exceptions are the substances listed in Appendices E and F and those substances designated with a "C" or Ceiling value. Appendix D) Time-weighted averages permit excur sions above the limit provided they are 1 compensated by equivalent excursions below the limit during the workday. In some in stances'it may be permissible to calculate the average concentration for a workweek rather than for a workday. The degree of permissible excursion is related to the magnitude of the threshold limit value of a particular substance as given in Appendix D. The relationship between threshold limit and permissible excursion 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. AH factors must be taken into consideration in arriving at decision as to whether a hazardous condition exists. Threshold limits are based on the best available information from industrial ex perience, 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 substance 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; consequently, the 2 96 precision of the estimated TLV is also sub ject to variation and the latest Documenta tion should be consulted in order to assess the extent of the. data available for a given substance. 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 physical irritation may initiate, promote or accelerate physical impairment through interaction with other chemical or biologic agents. 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 contaminants as low as is practical. These limits are intended for use in the practice of industrial hygiene and should be interpreted and applied only by a person trained in this discipline. They are not in tended for use, or for modification for use, (1) as a relative index of hazard or toxicity, (2) in the evaluation or control of com munity air pollution nuisances, (3) in esti mating the toxic potential of continuous, uninterrupted exposures, (4) as proof or disproof of an existing disease or physical condition, or (5) for adoption by countries whose working conditions differ from those in the United States of America and where substances and processes differ. Ceiling vs Time-Weighted Average Limits. Although the time-weighted average con centration provides the most satisfactory, 3 alter akin absorption. This attention-calling, designation is intended to suggest appro priate measures for the prevention of cu taneous absorption so that the threshold limit is not invalidated. Mixtures. 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 develop ing threshold limit values for mixtures, and methods for their development, amplified by specific examples arc given in Appendix C. Nuisance Particulate$. In contrast to fibrogenic dusts which cause scar tissue to be formed in lungs when inhaled in excessive 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 inappro priate to the extent that there is no dust which does not evoke some celhil&r response in the lung when inhaled in sufficient amount. However, the lung-tissue reaction caused by inhalation of nuisance dusts has the following characteristics: 1) The archi tecture of the air spaces remains intact. 2) Collagen (scar tissue) is not formed to a significant extent. 3) The tissue reaction is potentially reversible. Excessive concentrations of nuisance dusts in the workroom air may seriously reduce visibility (iron oxide, carbon black), may cause unpleasant deposits in the eyes, ears 5 practical way of monitoring airborne agents for compliance with the limits, there are certain substances for which it is inappro priate. In the latter group are substances which are predominantly fast acting and whose threshold limit is more appropriately based on this particular response. Sub stances with this type of response are best controlled by a ceiling "C" limit that should not be exceeded. It is implicit in these definitions that the manner of sampling to determine compliance with the limits for each group must differ; a single brief sample, that is applicable to a "0" limit, is not appropriate to the time-weighted limit; here, a sufficient number of samples are needed to permit a time-weighted average concentration throughout a complete cycle of operations or throughout the work shift. Whereas the ceiling limit places a definite boundary which concentrations 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. The magnitude of these excur sions may be pegged to the magnitude of the threshold limit by an appropriate factor shown in Appendix D. It should be noted that the same factors are used by the Com mittee in making a judgment whether to in clude or exclude a substance for a "C" listing. "Skin" Notation. Listed substances fol lowed by the designation "Skin" refer to the potential contribution to the overall expo sure by the cutaneous route including mucuous membranes and eye, either by airborne, or more particularly, by direct contact with the substance. Vehicles can 4 and nasal passages (Portland Cement dust), or cause injury to the skin or mucous mem branes by chemical or mechanical action per se or by the rigorous skin cleansing procedures necessary for their removal. A threshold limit of 10 mg/m\ or 30 mppcf, of total dust <1% quartz is recom mended 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 concentrations. Neither does it apply to those substances which may cause physiologic impairment at lower concentra tions but for which a threshold limit has not yet been adopted. Some nuisance particu lates are given in Appendix E. 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 physiologic effects. A TLV may not be recommended for each simple asphyxiant because the limiting factor is the available oxygen. The minimal oxygen con tent should be 18 percent by volume under normal atmospheric pressure (equivalent to a partial pressure, p(>2 of 135 mm Hg). Atmospheres deficient in O2 do not provide adequate warning and most simple asphyx iants are odorless. Several simple asphyx iants present an explosion hazard. Account should be taken of this factor in limiting the concentration of the asphyxiant. Specific examples arc listed in Appendix F. Short-Term Limits {STLs). Because many industrial exposures are not continuous, 8-hour daily exposures, but are short-term, 6 October 1974, NATIONAL SAFETY NEWS 409972 0420 or intermittent, to which the TLVs do not necessarily apply, STLs for 5, 15, or 30 minutes for 142 substances have been put into the regulations of the Pennsylvania Department of Health (Chapter 4, Art. 432, Revised Jan, 25, 1968). These STLs repre sent the maximal average atmospheric con centration of a contaminant to which a worker may be exposed for the stipulated time. The concentration represents an upper limit of exposure and assumes that there is sufficient recovery between expo sures before another is initiated. The daily average exposure including that provided by the STL shall be such that the TLV shall not be exceeded. Similar STLs for a more restricted number of substances have been recommended by the American National Standards Institute. This standard-setting body refers to these short-term limits as "pcaks.,, Physical Factors. It is recognized that 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. 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 ex ample, continuous work at temperatures above 90F or overtime extending the work week more than 25%, might be considered gross deviations. In such instances judgment 7 must be exercised in the proper adjustments of the threshold limit values. Biologic Limit Values (BLVs). Other means exist and may be necessary for monitoring worker exposure other than re liance on the Threshold Limit Values for industrial air, namely, the Biologic limit Values. These values represent limiting amounts of substances (or their effects) to which the worker may be exposed without hazard to health or well-being as determined in his tissues and fluids or in his exhaled breath. The biologic measurements on which the BLVs are based can furnish two kinds of information useful in the control of worker exposure; (1) measure of the indi vidual worker's over-all exposure; (2) measure of the worker's individual and characteristic response. Measurements of response furnish a superior estimate of the physiologic status of the worker, and may be made of (a) changes in amount of some critical biochemical constituent, (b) changes in activity of a critical enzyme, (c) changes in some physiologic function. Measurement of exposure may be made by (1) determining in blood, urine, hair, nails, in body tissues and fluids, the amount of substance to which the worker was exposed; (2) determination of the amount of the mctabolitc(s) of the substance in tissues and fluids; (3) determi nation of the amount of the substance in the exhaled breath. The biologic limits may be used as an adjunct to the TLVs for air, or in place of them. The U.S. National Institute for Occupational Safety and Health is pro posing a series of these BLVs which will be issued from time to time as part of the 8' ' _____________________ October 1974, NATIONAL SAFETY NEWS Criteria Documents for recommended in dustrial air standards. Unlisted, substances. .There are a number of reasons why a substance does not appear in the Threshold Limit list; either insufficient information is available or it has not been brought to the attention of the Threshold Limits Committee from which a limit can be developed, or it is a substance that could be included in the Appendices E and F per taining to Nuisance Particulates and Simple Asphyxiants. Substances appearing in these appendices serve as examples only; the appendices are not intended to be inclusive. **Notice of Intent." At the beginning of each year, proposed actions of the Com mittee for the forthcoming year are issued in the form of a "Notice of Intended Changes." This Notice provides not only an oppor tunity for comment, but solicits suggestions of substances to be added to the list. The suggestions should be accompanied by sub stantiating evidence. The list of Intended Changes follows the Adopted Values in the TLV booklet. Legal Status. By publication in the Federal Register (Vol. 36, No. 105, May 29, 1971)'the Threshold Limit Values are now official federal standards for industrial air. Reprint Permission. This publication may be reprinted provided that written permission is obtained from the SecretaryTreasurer of the Conference and that it be published in its entirety. 9 Swbstanco ppm**1 * mg/m Anisidine (o, p-isomers) -- Skin.......................... Antimony & compounds (as Sb).......................... ANTU (alpha naphthyl thiourea)...................... Argon................................ Arsenic & compounds (as As)......................... Arsine............................... Asphalt (petroleum) fumes............................ Azinphos methyl--Skin. Bagon (Propaxur).......... Barium (soluble compounds)................. * Benzene--Skin................. Benzidine--Skin............ p-Bcnzoquinone, see Quinonc........................ Benzoyl peroxide............ Benzyl chloride............... Beryllium......................... Biphenyl, see Diphenyl. Bismuth tclluridc............ Bismuth telluride (Se-doped)................... Boron oxide..................... Boron tribromide............ C Boron trifluoride............. Bromine........................... Bromine pentafluoride.. Bromoform -- Skin........ 0.1 -- -- F -- 0.05 -- -- -- -- -- -- -- -- 1 -- -- -- -- -- 1 1 0.1 0.1 0.5 0.5 0.5 0.3 -- 0.5 0.2 5 0.2 0.5 0.5 -- Au -- 5 5 0.002 -- 10 5 10 10 3 0.7 0.7 5 Capital letters refer to Appendices. Footnotes (a thru h) see Pages 32 and 33. *1974 Addition. **Sce Notice of Intended Changes. 11 ADOPTED VALUES Sm Documentation for basis of TLVs Substance ppm-' mg/m* Abate................................ Acetaldehyde................... Acetic add....................... Acetic anhydride............ Acetone............................ Acetonitrile...................... Acetylene..................... ... Acetylene dichloride, see 1, 2-DichloroethyIene. Acetylene tetrabromide. Acrolein............................ Acrylamide -- Skin......... Acrylonitrile -- Skin. ... Aldrin -- Skin.................. Allyl alcohol -- Skin.... Allyl chloride................... Allyl glycidyl ether (AGE)--Skin............. Allyl propyl disulfide----Alundum (AI2O3)............ 4-Aminodipheny!--Skin. 2-Aminoethanol, see Ethanol&mine.............. 2-Aminopyridine............. Ammonia.......................... Ammonium chloride. fume.............................. Ammonium sulfamate (Ammatc).................... n-Amyl acetate................ sec-Amyl acetate........... Aniline -- Skin................ -- 100 10 s 1.000 40 F -- 1 0.1 -- 20 -- 2 1 5 2 -- -- 0.5 25 -- -- 100 125 5 10 180 25 20 2,400 70 -- 14 0.25 0.3 45 0.25 5 3 22 12 E A1* -- 2 18 10 10 525 650 19 Capital letters refer to Appendices. Footnotes (a thru h) see Pages 32 and 33. 10___________________________ ________________________ Substance ppn-.*> mg//m ^ Butadiene (1, 3- butadienc).................... 1,000 * Butane.............................. -- Butanethiol, see Butyl mercaptan.................... _ 2-Butanone...................... 200 2-Butoxy ethanol (Butyl Cellosolvc) -- Skin.... 50 Butyl acetate (n-butyl acetate)........................ 150 sec-Butyl acetate............ 200 tert-Butyl acetate.......... 200 ** n-Butyl alcohol--Skin... -- sec-Butyl alcohol............ 150 tert-Butyl alcohol.......... 100 C Butylamine -- Skin........ 5 C tert-Butyl chromate (as CrOj) -- Skin............ _ n-Butyl glycidyl ether (BGE).......................... 50 Butyl lactate.................. -- Butvl mercaptan............ 0.5 p-tcrt-Butyltolucnc........ 10 Cadmium (Metal dust and soluble salts)........ ___ *C Cadmium oxide fume (as Cd)............................... ___ Calcium carbonate.......... -- Calcium arsenate............ -- Calcium oxide................. -- Camphor (Synthetic). . . 2 Caprolactam Dust............................. ___ Vapor........................... 5 2,200 -- _ 590 240 710 950 950 -- 450 300 15 0.1 270 -- 1.5 60 ___ 0.05 E 1 5 12 1 20 Capital letters refer to Appendices. *1974 Addition. See Notice of Intended Changes. __________________12_________ 409972 0421 97 Subftance ppm*1 Carbaryl (Sevin).......... _ Carbon black................... -- Carbon dioxide................ 5,000t Carbon disulfide -- Skin. 20 Carbon monoxide............ 50 Carbon tetrachloride -- Skin.............................. Cellulose (paper fiber)... 10 -- Chlordanc--Skin........... -- Chlorinated c&mphene -- Skin.............................. -- Chlorinated diphenyl oxide.............................. Chlorine............................ 1 Chlorine dioxide.............. 0.1 C Chlorine trifluoride........ 0.1 C Chloroacetaldehyde........ 1 a-Chloroacetophenone (phen&cylchloride)___ 0.05 Chlorobenzene (monochlorobenzene).. 75 o-Chlorobemylidene malononitrile (OCBM) -- Skin.......................... 0.05 Chlorobromomethane... 200 2-Chloro-l, 3-butadiene see Chloroprene.......... Chlorodiphenyl (42% Chlorine) -- Skin........ -- Chlorodiphenyl (54% Chlorine) -- Skin........ 1-Chloro, 2, 3- epoxy- propane, see Epichlorhydrin............ mg/m3 5 3.5 9.000 60 55 65 E 0.5 0.5 0.5 3 03 0.4 3 0.3 350 0.4 1.050 1 0.5 Capital letters refer to Appendices. tSee 1974 Revised Documentation. 13 Substance ppm*> ing/m** Cumene--Skin.............. Cyanide (as CN) --Skin. Cyanogen......................... Cyclohexane.................... Cyclohexane!................... Cyclohexanone................ Cyclohexene.................... * Cyclohexylamine--Skin. Cyclopentadiene.............. 2. 4-D............................... DDT................................ DDVP, see Dichlorvos.. Decaborane--Skin........ Demeton--Skin.......... Diacetone alcohol (4- hydroxy-4-methyl2-pentanone)................ 1, 2-Diaminoethane, see Ethylenediamine........ Diazinon -- Skin............. Diazomethane................. Diborane.......................... 1,2-Dibromoethane (ethylene dibromide) -- Skin.......................... Dibrom........................ .. 2-N Dibutylaminoethanol --Skin.......................... Dibutyl phosphate.......... Dibutylphthalate............ C Dichloracetylene............. C o-Dichlorobensene.......... p-Dichlorobenzene.......... 50 -- 10 300 SO 50 300 10 75 -- -- -- 0.05 0.01 50 -- -- 0.2 0.1 20 -- 2 1 -- 0.1 50 75 245 5 -- 1,050 200 200 1,015 40 200 10 1 -- 0.3 0.1 240 -- 0.1 0.4 0.1 145 3 14 5 5 0.4 300 450 Capital letters refer to Appendioea. 1974 Addition. 15 Substance ppm*> mg//m ** i Diisobutyl ketone.......... Diisopropylamine -- Skin.............................. ; Dimethoxymcthane, see Methylal...................... ; Dimethyl acetamide -- ' Skin.............................. i Dimethylaminc............... ; Dimethylaminobenzene, sec Xylidcne................ Dimethylaniline (N- dimethylaniline) -- Skin.............................. Dimethylbenrene, see Xylene.......................... Dimethyl 1, 2-dibromo* 2-dichtoroethyl pbos- 1 phate, see DtBrora.... Dimethylformamide -- Skin.............................. 2, 6-Dimethylheptanone, see Diisobutyl ketone. 1, 1-Dimethylhydraxine ; --Skin.......................... Dimethylphthalate........ Dimethylsulfate -- Skin. Dinitrobenzene (all isomers)--Sirin.......... Dinitro-o-cresol -- Skin. Dinitrotoluene -- Skin.. Dioxane, technical grade 1 --Skin.......................... Diphenyl.......................... 25 5 __ 10 10 . 5 10 _ 0.5 -- -- 0.15 -- -- 50 0.2 150 20 _ 35 IS ___ 25 30 1 5 -- 1 0.2 1.5 180 1 Capital letters refer to Append CCS. Footnotes (a thru h) see Pages 32 and 33. ?*See Notice of Intended Changes. 17 Substance ppm-> mg//m 2-Chloroethanol. see Ethylene chlorohydrin. -- Chloroethylene, see Vinyl chloride.............. _ Chloroform (Trichloromethane)... 25 bis-Chloromethyl ether.. 0.001 1-Chloro-1-nitropropane. 20 Chloropicrin..................... 0.1 Chloroprene (2-chloro-I, 3-butadiene) -- Skin. . 25 * 0-Chlorotoluene............... 50 Chromates, certain insol uble forms..................... Chromic add and chromates (as CrOs).. Chromium, sol. chromic. chromous salts as Cr.. -- Coal tar pitch volatiles (benzene soluble frac tion: anthracene, BaP, phenanthrene, acri- dine, chrvsene, pyrene) A1* Cobalt, metal fume <fc dust................................ ** Copper fume..................... -- Dusts and Mists___ -- 'Corundum (AliOj).......... -- * 'Cotton Dust (raw)......... -- Crag herbicide............... -- Cresoi (all isomers) -- Skin............................... 5 Crotonaldehvde............... 2 120 A* 100 0.7 90 250 Au Oil 0.5 0.2 0.1 -- 1 E 0.2-> 10 22 6 Capital letters refer to Appendices, (footnotes (a thru h) see Pages 32 and 33. *1974 Addition. . **See Notice of Intended Changes, m) see p. 35. -___ .____________ 14_______________ Subttancs ppm#> mg/m Dichlorobenzidine-- Skin.............................. -- Dichlorodifluoromethane. 1.000 1, 3-Dichloro-5, 5- dimethyl hydantoin... -- 1, I-Dichloroethane........ 200 1,2-Dichloroethane........ 50 1, 2-Dichloroethylene... 200 Dichloroethyl ether-- Skin......................... 5 Dichlorometh&ne, see Methylene chloride... -- Dichloromonofiuoro- methane........................ 1,000 C1, 1-Dichloro-l- nitroethane.................. 10 1, 2-Dichloropropane, see Propylenedichloride... -- Dichlorotetrafluoro- ethane.......................... 1,000 Dichlorvos (DDVP) -- Skin.............................. 0.1 Dieldrin--Skin.............. -- Diethylamine.................. 25 Diethylamino ethanol -- Skin.............................. 10 Diethylene triamine -- Skin.............................. 1 Diethylether, see Ethyl ether.............................. -- Difiuorodibromo- methane........................ 100 CDiglycidyl ether (DGE). 0.5 Dihydroxybenzene, see Hydroquinone............. -- Au 4.950 0.2 320 200 790 30 -- 4,200 60 -- 7,000 1 0.25 75 50 4 -- 860 2.8 -- Capital letters refer to Appendices. Footnotes (a thru h) see Pages 32 and 33. '<__________________ 16_______________ Substance Diphenyl amine.............. Diphenylmethane diisocyanate see Methylene bisphenyl isocyanate (MDI).... Dipropylene glycol ' methyl ether -- Skin. Diquat.............................. Di-sec, octyl phthalate - (Di-2-ethylhexylphthalate).................... * Disyston--Skin............... Emery.............................. Endosulfan (Thiodan) -- Skin........................ . Endrin -- Skin................ Epichlorhvdrin -- Skin.. EPX --Skin.................... I, 2-Epoxypropane, see Propylencoxide............ 2, 3-Epoxy-l-propanol, isee Glycidol................. Ethane.............................. Ethancthiol, see Ethylmercaptan.......... Ethanolamine.................. 2-Ethoxye(hanol--Skin. 2-Ethoxyethylacctate (Cellosolve acetate) -- Skin.......................... Ethyl acetate.................. Ethyl aciylate -- Skin... Ethyl alcohol (eth&not).. Ethylamine...................... ppm*1 100 -- -- -- -- -- 5 -- -- -- F -- 3 100 100 400 25 1,000 10 mg//m 10 -- 600 0.5 5 0.1 E 0.1 0.1 19 0.5 -- -- -- 6 370 540 1,400 100 1,900 18 Capital letters refer to Appendices. 1974 Addition. ' 18 409972 0422 October 1974, NATIONAL SAFETY NEWS Swbttonc# PPm*1 mfl//m Ethyl sec-amyl ketone (5- methyl-3-heptanone).. 25 Ethyl benzene.................. 100 Ethyl bromide................ 200 Ethyl butyl ketone (3- Heptanone).................. 50 Ethyl chloride.................. 1,000 Ethyl ether...................... 400 Ethyl formate.................. 100 Ethyl mercaptan............ 0.5 Ethyl silicate................... 100 Ethylene.......................... F Ethylene chlorohydrin -- Skin.............................. 5 Ethylenediamine............. 10 Ethylene dibromide, see ], 2-Dibromoethane... -- Ethylene dichloride, see 1, 2-Dichloroethane... _ Ethylene glycol, particu late ................................ Ethylene glycol, vapor .. 100 C Ethylene glycol dinitrate and/or Nitroglycerin-- Skin.............................. 0.2*1 Ethylene glycol mono- methyl ether acetate (Methyl cellosolve ace tate)-- Skin................ 25 Ethylene imine -- Skin. 0.5 Ethylene oxide................ 50 Ethylidine chloride, see 1, 1-Dichloroethane... CEtbylidene norbomene.. 5 130 435 890 230 2,600 1,200 300 1 850 -- 16 25 _ _ 10 260 120 1 90 _ 25 Capital letters refer to Appendices. Footnotes (a thru h) see Pages 32 and 33. "1974 Addition. 19 Subtonc ppm*' mfl/m* Hexafluoroaeetone.......... ** Hexane (it-bexane).......... 2-Hexanone...................... Hexone (Methyl isobutyl ketone)......................... sec-Hexyl acetate............ Hydrazine-- Skin.......... Hydrogen........................ Hydrogen bromide.......... C Hydrogen chloride.......... Hydrogen cyanide-- Skin.............................. Hydrogen fluoride.......... Hydrogen peroxide......... Hydrogen selenide.......... Hydrogen sulfide............ Hydroquinone................. Indene.............................. Indium and 'compounds. as In............................. C Iodine............................... ** Iron oxide fume.............. Iron pentacarbonyl........ Iron salts, soluble, as Fe. Isoamyl acetate.............. Isoamyl alcohol.............. Isobutyl acetate.............. ** Isobutyl alcohol.............. * Isophorone....................... Isopropyl acetate............ Isopropyl alcohol--Skin. Isopropylamine............... Isopropylether................ Isopropyl glyeidyl ether (IGE)........................... 0.1 -- 100 100 50 1 F 3 5 10 3 1 0.05 10 -- 10 -- 0.1 -- 0.01 -- 100 100 150 -- -- 250 400 5 250 50 0.7 -- 410 410 300 1.3 -- 10 7 11 2 1.4 0.2 15 2 45 0.1 1 -- 0.08 1 525 360 700 -- -- 950 980 12 1,050 240 Capital letters refer to Appendices. ""See Notice of Intended Changes. 21 Subttancs ppm*1 mg/m'*' K-Ethylmorpholine-- Skin............................... 20 Ferbam............................. -- Ferrovanadium dust___ -- Fluoride (as F)................ -- Fluorine........................... 1 Fluorotrichlororaethane. 1,000 ! Formaldehyde.................. 2 Formic acid...................... 5 Furfural -- Skin.............. 5 ` Furfuryl alcohol.............. 5 Gasoline............................ -- Germanium tetrahydride 0.2 Glass, fibrous** or dust... -- Glvcerin mist.................. -- Glycidol (2, 3-Epoxy-I- propanol)...................... 50 Glycol monoethyl ether, see 2-Ethoxyethanol.. _ Graphite, (Synthetic)... -- _Guthion, see Azinphosmethyl.......................... Gvpsum............................ -- Hafnium........................... -- Helium.............................. F Heptachlor--Skin......... -- ' Heptane (n-heptane).... -- ' Hexachlorocyclopenta- diene............................. 0.01 Hexachloroethane -- Skin........ ;.................... 1 Hexachloronaphthalene' -- Skin.......................... _ 94 10 I 2.5 2 5,600 3 9 20 20 B* 0.6 E E 150 _ E _ E 0.5 -- 0.5 -- 0.11 10 0.2 Capital letters refer to Appendices. Footnotes (a thru h) see rages 32 and 33. "1974 Addition. ""See Notice of Intended Changes. ___________ 20_________ Substance ppma} mg/,m* Kaolin............................... -- Ketene.............................. 0.5 Lead, inorg., fumes and dusts............................. -- Lead arsenate.................. -- Limestone......................... Lindane............................. ---- Lithium hydride.............. * L.P.G. (Liquified petro- leum gas).......... ............ 1,000 Magnesite......................... -- Magnesium oxide fume.. -- Malathion -- Skin.......... -- Maleic anhydride............ 0.25 ' Manganese and com- pounds, as Mn............ ` Manganese cyclopenta- dienvl tricarbonyl (as Mn)--Skin............ Marble.............................. Mercury (Alkyl com- pounds) -- Skin.......... 0.001 `Mercury (All forms ex- cept alkvl).................... -- Mcsitvl oxide................... 25 Methane........................... F Meth&nethiol, see Methyl mercaptan.................... -- Methoxychlor.................. ' 2-Methoxyethanol--Skin (Methyl cellosolve)... 25 Methyl acetate................ 200 Methyl acetylene (pro- pyne)............................. 1,000 E 0.9 0.15 0.15 E 0.5 0.025 1,800 E 10 10 1 5 0.1 E 0.01 0.05 100 -- -- 10 80 610 1,650 Capital letters refer to Appendices. *1974 Addition. 22 Subslanco ppm*1 mg/m Methyl aeetylenepropadiene mixture (MAPP)....................... Methyl acrylate--Skin. Methyl acrylonitrile -- Skin.............................. Methylal (dimethoxy- 1,000 10 1 methane)...................... 1,000 Methyl alcohol (metha nol)--Skin.................... 200 Methylaminc................... 10 Methyl amyl alcohol, see Methyl isobutyl carbi- nol................................. Methyl 2-cyanoacrylate. Methyl isoamyl ketone.. Methyl (n-arayl) ketone (2-Heptanone)............. Methyl bromide--Skin. Methyl butyl ketone, see 2-Hexanone.................. Methyl cellosolve--Skin see 2-Methoxyethanol. Methyl cellosolve acetate -- Skin, see Ethylene glycol monomethyl ether acetate................ Methyl chloride.............. Methyl chloroform......... * * Methylcyclohexane........ Methylcyclohexanol.... o-Methylcyclohexanone--Skin.......................... Methylcyclopentadienyl manganese tricarbonyl (as Mn) -- Skin.......... -- 2 100 100 15 -- -- -- 100 350 -- 50 50 0.1 See Notice of Intended Changes. 1,800 35 3 3,100 260 12 8 475 465 60 210 1,900 235 230 0.2 23 Substance ppm*1 mg/m Mcthvl demoton -- Skin. Methyl cthvl ketone (MEK), see 2-Butanonc....................... *0 Methyl ethyl ketone peroxide.............. Methyl formate.......... r. Methyl iodide -- Skin... Methyl isohutvl carbinol -- Skin.......................... Methyl isobutyl ketone. sec Hoxonc................... Methyl isocyanate -- Skin............................... Methyl mercaptan.......... Methyl methacrylate___ Methyl parathion--Skin. Methyl propyl ketone. see 2-Pentanone.......... C Methyl silicate................ C a Methyl stvrene............. C Methylene bisphenyl iso- cyanate (MD1)............ ** Methvlene chloride (di- chloromothane)........... * -M'-Methylene bis (2- chloraniline)--Skin. .. *C Methylene bis (-1-cvclo- hexylisocvanate)......... Molybdenum (soluble compounds).. (insoluble compounds). -- -- 0.2 100 5 25 -- 0.02 0.5 100 -- J -- 5 100 0.02 -- 0.02 0.1 -- -- 0.5 ----- - 1.0 250 28 100 -- 0.05 1 410 0.2 -- 30 480 0.2 -- A5 0.11 O 10 Capital letters refer to Appendices. Footnotes (a thru h) ace Pages 32 and 33. 1974 Addition. See Notice of Intended Changes. 24 October 1974, NATIONAL SAFETY NEWS l 409972 0423 99 Substanco ppm*' mfl/m* Monomethyl Aniline -- Skin.............................. 2 9 C Monomethyl hydrazine --Skin.......................... 0.2 0.35 Morpholine -- Skin........ 20 70 Naphtha (coal tar)......... 100 400 Naphthalene.................... 10 50 0-N&phthyl&mme............ -- A" Neon................................. F -- Nickel carbonyl.............. 0.001 A ' 0.007 Nickel, metal and insol uble compounds (as Ni) _ 1 Nickel, soluble com- pounds (as Ni)............ -- -- Nicotine -- Skin.............. 0.07S 0.5 Nitric arid........................ 2 5 Nitric oxide...................... 25 30 p-Nitroaniline--Skin... 1 6 Nitrobenzene -- Skin.... 1 5 p-Nitrochlorobenzene -- Skin.............................. 1 4-Nilrodiphenyl.............. -- A'- Nitroethane..................... 100 310 C Nitrogen dioxide............. 5 9 Nitrogen trifluoride........ 10 29 Nitroglycerin--Skin___ 0.2 2 Nitromethane.................. 100 250 l-Nitropropane................ 25 90 2-Nitropropane................ 25 90 N-Nitrosodimethyl&mine (dimetbylnitrosoamine) --Skin.......................... A* Nitrotoluene--Skin.... 5 30 Capital letters refer io Appendices. Footnotes (a thru h) see rages 32 and 33. ""See Notice of Intended Changes. 25 Substance ppm*' img//m Nitrotrichloromethane, see Chloropicrin.......... -- Nitrous oxide................... F Octachloronaphthalene --Skin.......................... -- ' Octane............................... ___ Oil mist, particulate.... -- Oil mist, vapor................ *>B* 'Osmium tetroxide........... ' 0.0002 Oxalic acid....................... ___ Oxygen difluoride............ 0.05 Osone................................ 0.1 ' Paraffin wax fume. -- Paraquat--Skin............ -- Parathion--Skin............ -- Pentaborane.................... 0.005 Pen tachloronapbthalene -- Skin.......................... -- Pentachlorophenol --Skin___ ................... -- Pentaerythritol................ -- ' Pentane............................ ___ 2-Pentanone..................... 200 Ferchloroethylene........... 100 Ferchloromethyl mercaptan.................... 0.1 Perchloryl fluoride.......... ,3 Petroleum Distillates (naphtha)..................... Phenol -- Skin................. 5 Phenothiarine -- Skin... -- p-Phenylene diamine -- Skin............................... -- -- -- 0.1 5" -- 0.002 1 0.1 0.2 0.2 0.5 0.1 0.01 0.5 0.5 E ___ 700 670 0.8 14 ___ 19 5 0.1 Capital letters refer to Appendica. Footnotes (a thru h) see Pages 32 and 33. *1974 Addition. **See Notice of intended Changes. --------------------------- 26 Subttance ppm"> Phenyl ether (vapor).... Phenyl ether-Diphenyl mixture (vapor).......... Phenylethylene, see Styrene......................... Phenyl glyridyl ether (PGE).......................... Phenylhydrazine--Skin. C Phenylphosphine............ Phorate(Thimet)--Skin Phosdrin (Mevinphos) -- Skin.......................... Phosgene (carbonyl chlo ride) ............................... Phosphine......................... Phosphoric arid.............. Phosphorus (yellow)----Phosphorus pentachlo- ride................................ Phosphorus pentasulflde. Phosphorus trichloride.. Phthalic anhydride......... Picric add -- Skin.......... Pival (2-Pivatyl-l, 3- indandione).................. Plaster of Paris................ Platinum (Soluble Salts) asPt.............................. Polychlorobiphenyls, see Chlorodiphenyls.......... Polytetrafluoroefhylene decomposition prod ucts ............................... C Potassium hydroxide----- 1 1 __ 10 5 0.05 -- 0.01 _ 0.3 -- -- _ -- 0.5 2 -- -- -- _ -- -- mg//m'*' 7 7 _ 60 22 0.25 0.05 0.1 _ 0.4 1 0.1 1 1 3 12 0.1 0.1 E 0.002 -- B1 2 Subttanc* Ppm*' * Silicon tetrahydride (Silane)......................... 0.5 Silver, metal and soluble compounds................... -- Sodium fluoroacetate 1 (1080) -- Skin.............. -- *C Sodium hydroxide.......... -- Starch............................... -- Stibine............................... 0.1 V Stoddard solvent............ -- Strychnine........................ -- Styrene (Monomer) (Phenyl ethylene).... 100 1 Sucrose.............................. -- , Sulfur dioxide.................. 5 Sulfur hexafluoride......... 1,000 : Sulfuric acid..................... -- . Sulfur monochloride.... 1 Sulfur pentafluoride..... 0.025 i Sulfur tetrafluoride........ 0.1 , Sulfuryl fluoride.............. Systox, see Demcton... ; 2, 4, 5-T............................ Tantalum............. ........ 5 -- -- -- TEDP --Skin................. ' --- Teflon decomposition products........................ -- Tellurium......................... -- Tellurium hexafluoride . 0.02 TEPP --Skin.................. 0.004 C Terphenyls....................... 1 1, 1, 1, 2-Tetrachloro-2, 2-difluoroethane.......... 500 mg. /.ma1 0.7 0.01 0.05 __ E 0.5 -__ 0.15 420 E 13 6,000 1 6 0.25 0.4 20 -- 10 5 0.2 B` 0.1 0.2 0.05 9 4,170 Capital letters refer to Appendices. 1974 Addition. See Notice o( Intended Changes. 27 Substance ppm*' mg//m^ Propane............................. fi Propiolactone............... Propargyl alcohol--Skin. n-Propyl acetate.............. Propyl alcohol--Skin... n-Propyl nitrate............... Propylene dichloride (1, 2-Dichloropropane)... Propylene glycol mono methyl ether................. Propylene imine -- Skin. Propylene oxide............... Propyne, see Methyl- acetylene....................... Pyrethrum........................ Pyridine............................ Quinone............................. RDX--Skin................... Rhodium, Metal fume and dusts (as Rh)___ Soluble salts............. Ronnel............................... Rosin Core Solder, pyrolysis products (as . formaldehyde)............. Rotenone (commercial).. Rouge................................ Selenium compounds (as Se)................................. Selenium hexafluoride. -. 1 Sevin (see Carbaryl)... 'Silane (see Silicon tetra- hydride)........................ Silicon............................... Silicon carbide................. F -- 1 200 200 25 75 100 2 100 -- -- 5 0.1 -- ---- -- -- -- . 0.05 -- _ -- -- -- A 2 840 500 110 350 360 5 240 -- 5 15 0.4 1.5 0.1 0.001 10 0.1 5 E 0.2 0.4 -s- E E Capital letters refer to Appendices. Footnotes (a thru h) see Pages 32 and 33. *1974 Addition. 'See Notice of Intended Changes. 29 Substance ppm*' mg/m 1, 1, 2, 2-Tetrachlorol, 2-difluoroethane.......... 1,1, 2, 2-Tetrachloro1 ethane -- Skin.............. Tetrachloroethylene, see Perchloroethylene___ Tetrachloromethane, see Carbon tetrachloride.. Tetrachloronaphthalene -- Skin.......................... Tetraethyl lead (as Pb) . --Skin.......................... Tetrahydrofuran............. Tetramethyl lead (as Pb) -- Skin.......................... Tetramethyl succinoni, trile--Skin.................. Tetranitromethane___ .. Tetryl (2, 4, 6- trinitrophenylmethylnitramine) -- Skin............................... Thallium (soluble com pounds)--Skin (as Tl). Thiram........................... Tin (inorganic com pounds, except SnH< and SnCb) as Sn.......... Tin (organic compounds) -- Skin (as Sn)............ Tin oxide......................... Titanium dioxide............ . Toluene (toluol) --Skin. C Toluene-2, 4- diisocyanate................ 500 5 _ -- -- _ 200 __ 0.5 l -- __ -- -- 100 0.02 4,170 35 _ -- 2 0.100" 590 0.150" 3 8 1.5 0.1 5 2 0.1 E E 375 0.12 Capital letters refer to Appendices. *1974 Addition. ___________ ________ Capital letters refer to Appendices. Footnotes (a thru h) see Pages 32 and 33. 30 ipo ' October 1974, NATIONAL SAFETY NEWS Subztanc* . J*> ppm*' mg/m o-Toluidine....................... 5 ' Toxaphene, see Chlori- nated camphene.......... -- Tributyl phosphate........ -- 1, 1, 1-Trichloroethane, see Methyl chloroform. -- 1, 1, 2-Trichloroethane -- Skin.......................... 10 Trichloroethylene............ 100 Trichloromethane, see Chloroform................... -- Trichloronaphthalene -- Skin............................... -- 1,2,3-Trichloropropane. 50 1, 1, 2-Trichloro 1, 2, 2- trifiuoroethane............. 1,000 Triethylamine.................. 25 Trifluoromonobromo- methane........................ 1,000 Trimethyl benzene.......... 25 2,4,6-Trinitrophenol, see Picric acid.................... -- 2, 4, 6 -- Trinitrophenyl- methylnitramine, see Tetryl............................ -- Trinitrotoluene -- Skin.. 0.2 Triorthocresyl phosphate................ . - --- Triphenyl phosphate.... -- Tungsten & compounds. as W Soluble...................... Insoluble................... -- -- Turpentine....................... 100 Uranium (natural) sol- uble & insoluble com- pounds, as U................ -- 22 --- ` 5 -- 45 535 -- 5 300 7,600 100 6.100 120 -- -- 1.5 0.1 3 1 5 560 0.2 31 g) According to analytically determined composition. h) For control of general room air, biologic monitoring is essential for personnel control. Radioactivity: For permissible concentra tions of radioisotopes in air, see U.S. De partment of Commerce, National Bureau of Standards Handbook 69, "Maximum Per missible Body Burdens and Maximum Per missible Concentrations of Radionuclides in Air and in Water for Occupational Expo sure," June 5, 1969. Also, see U.S. Depart ment of Commerce National Bureau of Standards, Handbook 59, "Permissible Dose from External Sources of Ionizing Radia tion," September 24, 1954, and addendum of April 15,1958. A report, Basic Radiation Protection Criteria, published by the Na tional Committee on Radiation Protection, revises and modernizes the concept of the NCRP standards of 1954, 1957 and 1958; obtainable as NCRP Rept. No. 39, P.O. Box 4867, Washington, D.C. 20008. MINERAL DUSTS Substance SILICA, Si02 Crystalline Quartz TLV in mppcf: 300* % quartz + 10 TLV for respirable dust in mg/m*: 10 mg/m'** % Respirable quartz 4* 2 33 Substance ppm*' mg//mJk> Vanadium (V2Os), as V Dust.............................. C Fume............................. Vinyl acetate................... Vinyl benzene, see Styrene................................ Vinyl bromide.................. ** Vinvl chloride.................. Vinylcyanide, see Acrylonitrile................. Vinyl toluene................... Warfarin........................... Wood dust (non&llergenic)............ Xvlene (xylol) -- Skin. . Xvlidine -- Skin.............. Yttrium............................. Zinc chloride fume........ Zinc oxide fume............... * Zinc stearate.................... Zirconium compounds (as Zr)........................... -- -- 10 -- 250 -- -- 100 -- -- 100 5 -- -- -- -- -- 0.5 0.05 30 -- 1,100 -- -- 480 0.1 5 435 25 1 1 5 E 5 a) Parts of vapor or gas per million parts of contaminated air by volume at 25 C and 760 mm. Hg. pressure. b) Approximate milligrams of substance per cubic meter of air. d' An atmospheric concentration of not more than 0.02 ppm, or personal protec tion may be necessary to avoid headache. e' <7 nm in diameter. H As sampled by method that does not collect vapor. Capital letters refer to Appendices. *1974 Addition. **$e Notice of Intended Changes. 32 TLV for "total dust," res pirable and nonrespirable: 30 mg/m* % quartz + 3 Cristobalite........ Use one-half the value cal culated from the count or mass formulae for quartz. Tridymite Use one-half the value calculated from formulae for quartz. Silica, fused Use quartz formulae. Amorphous.......................................... 20 mppcf0 SILICA TES (< i% quartz) `Asbestos, all format Graphite (natural) Mica `Mineral wool fiber Perlite Portland Cement Soapstone Talc (nonasbestiform) Talc (fibrous) use Asbestos limit. Trcmolitc, sec Asbestos. `Tripoli, use respirable*' 5 fibers/cc> 5pm in length*'; Au 15 mppcf 20 mppcf 10 mg/m1 30 mppcf 30 mppcf 20 mppcf 20 mppcf mass quartz formula COAL DUST (bituminous). 2 mg/m1 (respirable dust frac tion < 5% quartz). If > 5% quartz use respirable mass formula. *1974 Addition. fA more stringent TLV for erocidolite may be required. ________________ 34____________________ October 1974, NATIONAL SAFETY NEWS NUISANCE PARTICULATES (see Appendix E) 30 m.p.p.c.f. or 10 mg/m*'* of-total dust < 1% quartz Conversion factors mppcf X 35.3 = million particles per cubic meter = particles per c.c. i) Millions of particles per cubic foot of air, based on impinger samples counted by light-field technics. j) The percentage of quarts in the formula is the amount determined from airborne samples, except in those instances in which other methods have been shown to be applicable. k) Both concentration and percent quartz for the application of this limit are to be determined from the fraction pass ing a sire-selector with the following characteristics: Aerodynamic Diameter (Mm) % passing (unit densitv sphere) selector <2 90 2.5 75 3.5 50 5.0 25 10 0 l) containing <1% quartz; if quartz con tent > 1%, use formulae for quartz. m) Lint free dust as measured by the verticalclutriator, cotton-dust sampler described in the Transactions of the National Con ference on Cotton Dust, J. R. Lynch, pg. 33, May 2. 1970. 35 n) As determined by the membrane filter method at 400-450 X magnification (4 mm objective) phase contrast illumi nation. o) Based on "high volume" sampling. p) "Respirable" dust as defined by the British Medical Research Council Cri teria (1) and as sampled by a device producing equivalent results (2). (1) Hatch, T. E. and Gross, P-, Pul monary Deposition and Retention of Inhaled Aerosols, p. 149. Academic Press, New York, New York, 1964. (2) Interim Guide for Respirable Mass Sampling, AIHA Aerosol Technology Committee. AHIA J. 31: 2, 1970, p. 133. 409972 36 101 NOTICE OF INTENDED CHANGES (for 1974) These substances, with their correspond ing 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 ques tions the appropriateness ofs the values herein, the values will be reconsidered for the "Adopted" list. Documentation is available for each of these substances. Substance ppm*1 mg/m Arsenic, inorganic com pounds (as As).............. -- Benzene--Skin.................. 10 + Butane................................ 600 n-Butyl alcohol................. 50 + n-Butyl lactate.................. 5 Cadmium dusts & salts... -- CCadmium oxide fume.... -- Calcium cyanamide.......... -- Calcium hydroxide........... -- .Captan................................ -- Carbofuran........................ -- Carbon tetrabromide........ 0.1 Catechol (Pyrocatechol).. 1 Cesium hydroxide............. -- Chlorodifluoromethane... 1000 Chlorpyrifos (Dursban) --Skin........................ -- o-Chlorostyrene................ 50 0.25 30 1,450 150 25 0.05 0.05 0.5 2 5 0.10 1.4 4.5 2 3500 0.2 285 Capital letters refer to Appendices.' 1974 Revision or Addition. 37 Substance ppm*1 mg/m' 2-Chloro-6-(trichloro- mcthyl) pyridine (NServe).......................... -- Clopidol (Coyden).......... -- Copper fume...................... -- Crufomate (Ruelene)... -- + Dicyclopentadiene............ 5 Dicyclopent&dienyliron... -- Diethylphth&Iate.............. -- Dimethyl sulfate--Skin.. -- 3,5-Dinitro-o-toluamide (Zoalene)..................... -- Disulfuram........................ -- 2,6-Ditert. butyl-p-cresol - Dvfonatc............................ -- C Ethylene chlorohydrin -- Skin................................ 1 Fensulfothion (Dasanit).. -- Formamide........................ 20 C GluUraldehvdc................. 2 CGlutaraldehvdc (Alkaline activated)...................... -- Heptane............................. 400 Hexane............................... -100 Hexylene glvcol................ 25 Hydrogenated terphcnyls 0.4 Iodoform............................ 0.2 1 ron oxide fume................ B` Isobutvl alcohol................ 50 Isophorone........................ 5 Mothylcvclohexanc.......... 400 Methylene chloride (Di- chloromethane)............. 100 N ickcl, soluble salts (as Ni) -- 10 10 0.2 5 30 10 5 A* 5 2 10 0.1 3 0.1 30 8 0.25 1,600 300 125 4.4 3.0 5 150 25 1,600 360 0.1 Capital tetters refer to appendices. + I9?4 Addition or Revision. ____________ 38 Substance ppm*1 mg/m + Nonane................................ 200 1,050 Octane................................. 300 1,450 Pentane................................ COO 1,800 C Phosgene............................ 0.05 0.2 Picloram (Tordon)........ -- 10 + Resorcinol............................. 10 45 C Sodium azide....................... 0.1 0.3 C Sodium hydroxide............ -- 2.0 Stoddard Solvent................ 100 575 CSubtilisins (Proteolytic enzymes as 100% pure crystalline enzyme).... -- O.OOOOG#1 Succindialdehydc (see Glutaraldchyde)............ ` -- -- 4,4'-Thiobis (6-tert butyl- m-crcsol)........................... -- 10 Tricyclohexyltin hydrox ide (Plictran)................. -- 5 Triphenylaminc................... -- 5 Vinyl chloride.................... Pending A u Vinylidene chloride.......... 10 40 Welding fumes (Total Par ticulate)............................ -- 5&B4 m-Xylcnc.g.a'-Diaimne... -- 0.1 a) Parts of vapor or gas per million parts of contaiminated air by volume at 25 C and 7G0 mm. Hg. pressure. b) Approximate milligrams of particulate per cubic meter of air. NOTICE OF INTENDED CHANGES (Cool'd) MINERAL DUSTS Substance TLV Diatomaceous earth (Natural, uncalcined).. 1 rag/m* Capital letters refer to Appendices. lfl74 Addition. For explanations of o) and p), see pg. 36. 39 Silica flour.......................... Use respirable*1 mass formula for quartz. APPENDIX A Carcinogens The Committee lists below those sub stances in industrial use that have proven carcinogenic in man, or have induced cancer in animals under appropriate experimental conditions. Present listing of those sub stances carcinogenic for man takes three forms, those for which a TLV has been assigned (la), those for which environ mental conditions have not been sufficiently defined to assign a TLV (lb), and lc, those whose reassignment of a TLV is awaiting more definitive data, and hence should be treated as a lb carcinogen. la. Hitman Carcinogens --Substances recog nized as occupational carcinogens with an assigned TLV: Asbestos, all forms, 5 fibers/cc > 5/<m in length. bis (Chloromethyl) ether, lppb. Chromates, certain insoluble forms, (Ph, Zn, and chromatc-chromite ore, lOOMg/m*. as Cr) Coal tar pitch volatiles 200Mg/m* Nickel carbonyl, lppb lb. Human Carcinogens -- Substances known to be potent occupational car cinogens without an assigned TLV: 4-Aminodiphenvl (p-Xenylamine) Benzidine & its salts beta-Naphthylamine 4-Nitrodiphenyl lc. Human Carcinogens--Substances await ing reassignment of TLV because of 40 recently discovered carcinogenicity. Vinyl chloride, TLV (tending. For the substances in lb, no exposure or contact by any route, respiratory, skin or oral, as detected by the most sensitive methods, shall be permitted. "No exposure or contact" means hermitizing the processor operation by the best practicable engineering , methods. The worker should be properly equipped to insure virtually no contact with the carcinogen. 2. Experimental Carcinogens -- Industrial substances found to be capable of induc ing tumors under experimental condi tions in animals: TLV ; Beryllium 0.002 mg/m* 3, 3'-Dichlorobonzidinc Dimethyl sulfate Ethylcnimine 4, 4-Methylene bis (2-chloroaniline) N-Nitrosodimcthylaminc beta-Propiolactonc For the above, worker exposure by all routes should be carefully controlled to levels consistent with the animal and human experience data, except for those substances with a listed TLV. APPENDIX II B1 Polytetrafluoroetkylene* decomposition i products. Thermal decomposition of the fluorocarbon chain in air leads to the formation of oxidized products contain ing carbon, fluorine and oxygen. Because these products decompose in part by hydrolysis in alkaline solution, they can "Trade Names: Algoflon, Fluon, Halon, Teflon, Tetran 41 be quantitatively determined in air as 1 fluoride to provide an index of exposure. ' No TLV is recommended pending de termination of the toxicity of the prodi ucts, but air concentrations should be 1 kept below the limit of sensitivity of the . analytic method. B* Gasoline. The composition of gasoline varies greatly and thus a angle TLV for . all types of these materials is no longer applicable. In general, the aromatic hydrocarbon content will determine what 1 TLV applies. Consequently the content of benzene, other aromatics and additives should be determined to arrive at the appropriate TLV (Elkins, et al. A.I.H.AJ. U: 99,1963). B* Petroleum Distillates. For petroleum dis, tillates for which no specific TLV's are listed, approximate values can be ob' tsuned by use of the following equation: 100________ TLV %At 3.6(200 - B.P.C.) + 20 + -------------------- ppm % Ar 1.3(200 - B.P.C.) -f-10 where Al *= aliphatic component At = aromatic component B.P. = mean boiling point in de grees centigrade (normally the 50% distillation tem perature). The equation cannot be used if the benzene content of the fraction exceeds 1%. nor if the mean boiling point is above 200 C. A2. 102 4099720426 It may also lead to error if there are large amounts of hexane or cyclohexane in the distillate. If the molecular weight (average) is not known for the mixture, it can be ap proximated by the following equation: M.W. - %A1 + 0.88%Ar + 0.5(B.P.C.) - 100) B* Welding Fumes -- Total Particulate 5 mg/m* (N-O.C.)^ In electric or oxy-gas welding of iron or steel, galvanized iron or aluminum, the chief components of the fume are ordi narily oxides of iron, zinc or aluminum. Other fumes, as well as toxic gases may be present in significant amounts, how ever. Manganese, silicate and organic binders are commonly present in the coatings of welding rods for ferrous metals; fluoride in those for aluminum. And elements such as arsenic, copper, are sometimes found. Many aluminum rods contain appreciable quantities of silicon, and some have traces of beryllium. In shielded arc welding, ozone is often formed, and carbon monoxide has been reported when CO2 was utilized as shield gas. Oxides of nitrogen are more likely to be associated with oxy-gas than with electric arc welding. Because of the additional hazard created by toxic gases and traces to small amounts of fumes of more toxic de ments, the total fume concentration, when welding iron, mild steel or alumi num, should not exceed 5 mg/m* in the q) Not otherwise classified. 43 breathing zone of the welder or others in the area. The fumes from stainless steel, cadmiumor lead-coated steel, and other metals such as copper and nickel are consider ably more toxic and concentrations should generally be kept at a lower level, depending on the TLV's of the metals involved. In addition, in the shielded arc welding of aluminum, relatively large amounts of ozone may be generated, and the concentration of this gas may largely determine the health hazard. APPENDIX C C.l THRESHOLD LIMIT VALUES FOR MIXTURES When two or more hazardous substances are present, their combined effect, rather than that of either individually, should be given primary' consideration. 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 ex ceeded. Ci indicates the observed atmo spheric concentration, and T| the correspond ing threshold limit (Sec Example lA.a. and 1 A.c.). Exceptions to the above rule may be made when there is good reason to believe that the chief effects of the different harmful substances are not in fact additive, but ___ ____________ 44 _____ October 1974. NATIONAL SAFETY NEWS independent as when purely local effects on different organs of the body arc produced by the various components of the mixture. In such cases the threshold limit ordinarily is exceeded only when at least one member of the scries + or + yr-etcitself has a value exceeding unit (Sec Example 1A. c.). Antagonistic action or potentiation may occur with some combinations of atmo spheric contaminants. Such cases at present must be determined individually. Potenti ating or antagonistic agents are not neces sarily harmful by themselves. Potentiating effects of exposure to such agents by routes other than that of inhalation is also possible, e.g. imbibed alcohol and inhaled narcotic (trichloroethylene). Potentiation is charac teristically exhibited at high concentrations, less probably at low. When a given operation or process charac teristically emits a number of harmful dusts, fumes, vapors or gases, it will frequently be only feasible to attempt to evaluate the hazard by measurement of a single sub stance. 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 atmo spheric contaminants are welding, automo bile repair, blasting, painting, lacquering, certain foundry operations, diesel exhausts, etc. (Example 2 in lA.a.). 45 THRESHOLD LIMIT VALUES FOR MIXTURES EXAMPLES lA.a. General case, where air is analyzed for each component: a. Additive effects. (Note: It is essen tial that the atmosphere be analyzed both qualitatively and quantitatively for each component present, in order to evaluate compliance or noncompli ance with this calculated TLV.) Ci T, + --T, +--Tj +^ 1 Example No. lA.a: Air contains 5 ppm of carbon tetrachloride (TLV = 10 ppm) 20 ppm of ethylene di chloride (TLV = 50 ppm) and 10 ppm of ethylene dibromide (TLV -- 20 ppm) Atmospheric concentra tion of mixture = 5 + 20 + 10 = 35 ppm of mixture 5 20 10 + 50 10 20 25 + 20 + 25 50 1.4 Threshold Limit is ex ceeded. Furthermore, the TLV of this mixture may be calculated by reducing the total frac tion to 1.0; i.c. TLV of mixture 3y5j- = o25s ppm lA.b. Special case when the source of con taminant is a liquid mixture and the 46 atmospheric composition is assumed to be similar to that of the original material; e.g. on a time weighted average exposure basis, all of the liquid (solvent) mixture eventually evaporates. Additive effects (approximate solu tion) 1. The percent composition (by weight) of the liquid mixture is known, the TLVs of the con stituents must be listed in mg/m*. (Xote: In order to evaluate compli ance with this TLV, field sampling instruments should be calibrated, tn the laboratory, for response to this specific quantitative and qualitative air-vapor mixture, and also to frac tional concentrations of this mixture; e.g., 1/2 the. TLV; 1/10 the TLV; 2 X the TLV; 10 X the TLV; rtc.) TLV of mixture =* 1 f. f. f. TLV. + TLV. r TLV. + - TLV. Example No. 1: Liquid solvent contains (by weight) 50% heptane (TLV = 2000 mg/m*) 30% methylene chloride (TLV = 1740 mg/m*) 20% pcrchlorcthylene (TLV = 670 mg/m*) TLV of mixture 1 0.5 , 0.3 , 0.2 1600 360 670 47 11 " 0.00031 + 0.00083 + 0.0003 " 0.00144 = 692 mg/m3 To convert to ppm, consult TLV list: 50% heptane = 200 ppm 30% methylene chloride ** 33 ppm 20% perchloroethylene = 20 ppm TLV of mixture: 200 + 33 + 20 = 253 ppm lA.c. Independent effects. Air contains 0.15 mg/m* of lead (TLV, 0.15) and 0.7 mg/m* of sulfuric acid (TLV, 1). 0.15 0.15 = l; 0.7 1 : 0.7 Threshold limit is not exceeded. lB.a. General Exact Solution for Mixtures of N Components With Additive Ef fects and Different Vapor Pressures. c2 CD t2 t 1; ^ t. (2) C, + C2 + ... + G. = T, (2.D Cl + -^? + T -r T (3) Ci = apt, and by Raoult's Law, (4) pi = Fipi. Combine (3) and (4) to obtain (5) Cj = aFipi. Combining (1), (2,1) and (5), we obtain 48 409972 0427 103 (6) F'Pi T _l ^T _i "* , F.p." + ~T~ FiPi* _lFtp2 , , F.p." T, ^ T2+"-+-xT and solving for T, (6 1) T= F;P2 H------ + F.p," FiPi" , F;P2 F.p." T, + T2 + ` + --x;-- or = n Fjpi" (6.2) T = ` 1=n 2 FlPl T. T -- Threshold Limit Value in ppm. C -- Vapor concentration in ppm. p -- Vapor pressure of component in solution. p--Vapor pressure of pure com ponent. F -- Mol fraction of component in solution. a -- A constant of proportionality. Subscripts 1, 2,... n relate the above quantities to components 1, 2, ... n, respectively. Subscript i refers to an arbitrary component from 1 to n. Absence of subscript relates the quantity to the mixture. 49 lB.b. Solution to be applied when there is a reservoir of the solvent mixture whose composition does not change appreciably by evaporation. Solvent Exact Arithmetic Solution of Specific Mixture Mol. Density TLV wt. Mo! fraction in half-and- half solution by volume Trichloro ethylene (1) 131.4 1.46 g/mi 100 73mm Hg 0.527 Methyl- chloro form (2) 133.42 1.33 g/ml 360 125mm Hg 0.473 FiPi* -- (0.527) (73) 38.2 F2p2 - (0.473) (125) - 59.2 Try _ 38.2 + 59.2 (97.4) (350) ^ 3S.2 59.2 = 133.8 + 59.2 100 + 350 (97.4) (350) 193.0 f" TLV -- 177 ppm (Note difference in TLV when account is taken of vapor pressure and mol fraction in comparison with the above example where such account is not taken.) 2. A mixture of one part of (1) parathion (TLV, 0.1) and two parts of (2) EPN (TLV. 0.5). 50 C. O2 O.L 0.5 C. = 3Ci C, 2C, 0.1 "* 0.5 7Ct 3Ci 0.5 " T. C. C. 3Ci T. Cj = 2C, T. = - 0.21 mg/m* 1C. TLV for Mixtures of Mineral Dusts. For mixtures of biologically active mineral dusts the general formula for mixtures may be used. For a mixture containing 80% talc and 20% quarts, the TLV for 100% of the mixture is given by: TLV - -qj-Toj- " 80 mppcf 20 + 2.9 Essentially the same result will be obtained if the limit of the more (most) toxic component is used provided the effects are additive. In the above example the limit for 20% quartz is 10 mppcf. For another mixture of 25% quartz, 25% amorphous silica and 50% talc: TLV - wiok4- "70mppcf 2.9 + 20 + 20 The limit for 25% quarts approximates 8 mppcf. 51 APPENDIX D PERMISSIBLE EXCURSIONS FOR TIME- WEIGHTED AVERAGE (TWA) LIMITS The Excursion TLV Factor in the Table automatically defines the magnitude of the permissible excursion above the limit for those substances not given a "C" designa tion; i.e., the TWA limits. Examples in the Table show that nitrobenzene, the TLV for which is 1 ppm, should never be allowed to exceed 3 ppm. Similarly, carbon tetra chloride, TLV 10 ppm, should never be allowed to exceed 20 ppm. By contrast, those substances with a "C" designation are not subject to the excursion factor and must be kept at or below the TLV ceiling. These limiting excursions are to be con sidered to provide a "rule-of-thumb" guid ance for listed substances generally, and may not provide the most appropriate excursion for a particular substance e.g., the permissible excursion for CO is 400 ppm for 15 minutes. For appropriate excursions for 142 sub stances consult Pa. Rules & Regs., Chap. 4, Art. 432, and "Acceptable Concentrations," ANSI. Substance TLV Excursion Factor Max. Cone. Permitted for short time Nitro- benzene Carbon tetrachloride ppm 1 10 3 2 ppm 3 20 52 . Substance TLV Excursion Factor Max. Cone. Permitted for short time * o-Dichlorobenzene Acetone Boron trifiuoride ' Butylamine ppm so 1000 C1 C5 1.5 1.25 -- -- ppm 75 1250 1 5 EXCURSION FACTORS For all substances not bearing C notation Excursion TLV>0-1 (ppmormg/m*), Factor *3 TLV>1-10 * 2 , TLV >10-100 * * . ~1.5 TLV >100-1000 * * -1.25 The number of times the excursion above the TLV is permitted is governed by con formity with the Time-Weighted Average TLV. BASIS FOR ASSIGNING LIMITING *C" VALUES , By definition in the Preface, a listed value bearing a "C" designation refers to a "ceiling" value that should not be exceeded; all values should fluctuate below the listed value. This, in effect, makes the "C" designation a maximal allowable concentration (MAC). In general, the bases for assigning or not assigning a "C" value rest on whether excursions of concentration above a pro posed limit for periods up to IS minute* may result in a) intolerable irritation, b) chronic, or irreversible tissue change, or c) narcosis of sufficient degree to increase accident 53 proneness, impair self-rescue or materially reduce work efficiency. APPENDIX E Soma Nultonc* Particulates'* TLV, 30 mppcf or lOmg/m11 Alundum (AI3O3) Calcium carbonate "Calcium silicate Cellulose (paper fiber) Portland Cement Corundum (AI2O3) Emery Glass, fibrous** or dust Glycerin Mist Graphite (synthetic) Gypsum Vegetable oil mists (except castor, cashew nut, or similar irritant 1 oils) Kaolin limestone MagnetiteMarble Mineral Wool Fiber Pentaerythrito! Plaster of Paris Rouge Silicon Silicon Carbide Starch Sucrose Tin Oxide Titanium Dioxide Zinc Stearate q) When toxic impurities are not present, e.g. quartz < 1% r) <7j*m in diameter APPENDIX F Somo Simple Aaphyxiantc** Acetylene Argon Butane Ethane Ethylene Helium Hydrogen Methane Neon Nitrous oxide Propane a) As defined on pg. 6. *1974 Addition. 54 409972 0428 104: October 1974, NATIONAL SAFETY NEWS