Document zQZzROB5JRqbvzZBk43YpL1Za

TLVs" Threshoid Limit Values for Chemical Substances in workroom Air Adopted by ACGIH for 1975 1 1975 TLV AIRBORNE CONTAMINANTS CDMMI TTE FIecror P. Blt.jw. N.D., l.l.I.11. Paul E. C`apian, P.E., J1.P.H. Her\.rsv 3. Elkins, Ph.I). T . G . Frdrick, Sc.D. Paul Gross, 1f.D. John K. Iinauher, J1.P.H. ,JPBSP Lieherinan, P.E. T r w t R. Lewis, Ph.D. I<&h 1:. Long. Ph.D Frtvkricir T. JIcDrwnott, P.E. E. Masrromatteo. 31.D.(Can.) Col. Kalrer \IX*,-i,vin, -Jr., 1I.D. lleier Scheider. P.E.. C.I.H. Col. 3larshall Steinberg, Ph.D. Gordon J . Stopps. 1I.B. John F. Summersctt Ralph L`. Wands, M.S. CONSULTANTS James F. Morgan Theodore R. Torkelson, Sc.D. JIitchel! El. Zavon, 3f.D. Herbert E. dtokinger, Ph.D., Chairman FVilliam D. Wab-er, Recording Secretary P.O. Box 1937 Cincinnati OH 45201 PREFACE CHEMICAL CONTAMINANTS Threshold limit ralues refer to airborne concentrations of substances and wprc8sPnt conditions undw which i t i: tjciit.vc.d that nearly all ivorkfmmay be repeatedly espowd day aftrr day without sdwrse cffcct. Brcause of a-idr variation in individiial susceptibility, howevrr, a small percentage of workers may csppriencr discomfort from some substances at concmtrations at or b&nv thc thrwiiold limit: a smnllcar percentage may iJt' aifwtcd morr seriously by aggr:ivation of a prrwsisting condition or by development of an occupational illntass. Simple tests arc' now available (J. Occup. >led. 13: 564. 1973; .inn. X.Y.Acad. Sci., 151, --1rt. 2: S(j8, 19SSi that. ma?- be used to detwt those individuals hypcrsusceptible to a variety of industrial chemicals (respiratory irritants, hemolytic chemicals, organic isocyanatte, carbon disulfide t. These tests may he uacd i o screen out by appropriate job placemen: t.hc hyperrmctive worker and thus in efft'ct improve the "coverage" of the TLYs. Threshold limit ralues rrfer to timeweighted concentrations for a i-or 8-hour w-orkday and -IO-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 concentrations. (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 excursions above the limit provided they are 1 compensated by equivalent excursions below the limit. during t.he workday. In some in- starices it may k 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 arid perrnissitk 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 frquency with which high concentrations OCCUT, and the duration of such periods. -411 factors must be taken into consideration in arriving a t a decision as to whether a hazardous condition exists. Threshold limits are based on the best availab'ie information from industrial experience, from experimental human and animai 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 ~ precision of the estirnatd TLV is also subject to variation and the latest Docum.entation should be consulted in order to ftssws the extent of the data available for a givm substance. The committee holds to thp opinion that limits based on phvsical irritation should be considered no less binding rhnn those based on physical impairment. T h t w is increasing evidence that phydical irritatiun may initiate, promote or acceltratr phvsical impairment through interaction witti o r her chemical or biologic agents. In spite of the fact that serious injur:; is not believed likely as a result of osposurc. to the threshold limit conccritrations. t h e best practice is to maintain concentrations of all at.mospheric contaniinants BY low as is practical. These limits are intended for use in the practice of industrial hygiene and should he interpreted and applied only by a person trained in this discipline. They m! not intended for use, or for modification for use, (1) as a relative indes of hazard or toxicity, (2) in the evaluation or control of community air pollution nuisances, (3) in estimating 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'difftr. Ceding v8 Tim-Weighted Auerage L i m b . Although the time-weighted average concentration provides the most satisfactory, practical way of monitoring airborne agents 3 -. . .. for compliance with the limits, there are certain substances for which it is inapprrr priate. In the latter grouD are substances which are predormnantly fast acting and whose threshold limit is more appropnately based on this particular response. Substances with this type of response are best controlled by a ceiling "C" limit that should not be esceeded. It is implicit in these definitions that the 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 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 excursions may be pegged to the magnitude of the threshold limit by an appropriate factor shown in Appendx D. It should be noted that the same factors are used by the Committee in making a judgment whether to include or exclude a substance for a "C" listing. "Skin" ,Votatwn. Listed substances followed by the designation "Skin" refer to the potential contribution to the overall exposure 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. This attentionGslling 4 designation is intended to suggest appropriate measurps for the prevention of cutaneous absorption so that the threshold limit is not invalidated. Jf ittures. Special consideration should be given also to the application oi the TLVs in assessing the h d t h hazards which ma?; be associated with esposure 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 deve!opment, amplified by specific examples are given in Appendix C. Xuisance Partieulntes. In contra.st to fibrogenic dusts which cause scar tissue to be formed in lungs when inhaled ill 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 ressonable 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 lung-tissue reaction caused by inhalation of nuisance dusts has the following characteristics: 1) The architecture 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, may cause unpleasant depoaits in , the eyes, ears and n d passages (Portland ! Cement dust), or cause injury to the skin or 5 1 mucous membranes by chemical or mechan- minutes for 142 substances have been put ical action per se or by the rigorous skin into the regulations of the Pennsylvania cleansing procedures necessary for their Department of Health (Chapter 4, Art. 432, removal. Revised Jan. 25, 1968). These STLs repre- A threshold limit of 10 mg/ma, 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 a t higher concentrations. 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 particulates are given in Appendix E. Simple Aaphy&nts -"Inert" G a m br Vapors. A number of gasea and vapors, when present in high concentrations in air, sent the maximal average atmospheric concentration 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 STLsfor a more restricted number of substances have been recommended by the American Xational Standards Institute. This standard-setting body refers to these short-term limits as "peaks." act primarily as simple asphyxiants without other significant physiologic effects. A TLV Physical Factora. It is recognized that such physical facton as heat, ultraviolet may not be recommended for each simple and ionizing radiation, humiditv, abnormal asph-yxiant because the limiting factor is the pressure (altitude) and the like may place available oxygen. The minimal oxygen con- added stress on the body so that the effects tent should be 18 percent by volume under from exposure a t a threshold limit may be normal atmospheric pressure (equivalent to altered. Most of these stresses act adversely a partial pressure, pop of 135 mm Hg). to increase the toxic response of a substance. Atmospheres deficient in 02 do not provide Although most threshold limits have built-in adequate warning and most simple asphyx- safety factors to guard against adverse iants are odorless. Several simple asphyxiants present an explosion hazard. Account effects to moderate deviations from normal environments, the safety factors of most should be taken of this factor in limiting the substances are not of mch a magnitude as concentration of the asphyxiant. Specific to take care of gross deviations. For ex- - I examples are listed in Appendix F. ample, continuous work at temperatures t Shop1-Temr L i m b (STL8). Because many above W'T, or overgime extending the work- industrial exposures are not continuous, week more than 25%, might be conaidered %hour daily exposures, but are short-term, gross deviations. In such instances judgment or intermittent, to which the TLVs do not must be exercised in the proper adjustmenta neceassrily apply, STLs for 5, 15, or 30 ofthe "hreshold Limit Values. Brief & Scala 67 I (AZHAJ. 26, 467, 1975) have proposed as an effective means of providing health formulae for calculating the TL'C'Reduction surveillance of the worker. Factor for novel work schedules, i.e. 10-hr Udbted substances. There are a number workday. of reasons whv a substance does not appear BioEogk Limit Values (BLVa). Other means exist and may be necessary for monitoring worker exposure other than reliance 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 Kis exhaled in the Threshold Limt 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 pertaining to Kuisance Particulates and Simple Asphyxiants. Substances appearing in these appendices serve as examples only; the appendices are not intended to be inclusive. breath. The biologic measurements on "Notice of Intent." At the beginning of which the BLVs are based can furnish two each year, proposed actions of the Corn- kinds of information useful in the control of mittee for the forthcoming p a r are issued in worker exposure: (1) measure of the indi- the form of a "Xotice of Intended Changes." vidual worker's over-aU exposure; (2) This Xotice provides not only an oppor- measure of the worker's individual and tunity for comment, but solicits suggestions characteristic response. Measurements of I response furnish a superior eatimaw of the of substances to be added to the list. The euggestions should be accompanied by sub- physiologic status of the worker, and may be made of (a) changes in amount of some I stantiating evidence. The list of Intended Changes follows the Adopted Values in the critical biochemical constituent, (b) changes TLV booklet. in activity of a critical enzyme, (c) changes Legal Status. By publication in the in some physiologic function. Measurement I Federal Register (Vol. 36. X o . 105, May 29. of exposure may be made by (1)determining 1971) the Threshold Limit Values for 1968 in blood, urine, hair, nails, in body tissues are now official federal standards for indus- and fluids, the amount of substance to which trial air. the worker waa exposed; (2) determination Reprint Penniambn. This publication of the amount of the metabolite(s) of the may be reprinted provided that written substance in tissues and fluids; (3) determi- permission is obtained from the Secretary- nation of the amount of the substance in the Treasurer of the Conference and that it be exhaled breath. The biologic limits may be published in its entirety. used aa an adjunct to the TLVs for air. or in I place of them. The BTLS, and their 9880- "?3? r, ciated procedurm for determining compliana3 with them, should thus be regarded *E 89 ... . ADOPTED VALUES See Documentation for basis of TLVs (1974) Substonce PPm"' Abate. . . . . . . . . . . . . . . . . - Acetaldehyde . . . . . . . . . . 100 Acetic acid. . . . . . . . . . . . 10 C ,icetic anhydride. . . . . . . 5 Acetone . . . . . . . . . . . . . . . 1,ooo Acetonitrile. . . . . . . . . . . . 40 .lcetylene .............. F Acetylene dichloride, see 1, 2-Dichloroethylene . - Acetylene tetrabromide. 1 Acrolein. . . . . . . . . . . . . . . Acrylamide -Skin. . . . . -4crylonitrile-Skin. . . . Aldrin -Skin. . . . . . . . . . 0.1 - 20 - Allyl alcohol -Skin. . . . 2 Allyl chloride. . . . . . . . . . 1 Allyl glycidvl ether (AGE)-Skin.. . . . . . Allyi propyl disulfide.. . . Alundum (Al2Oai. . . . . . . 4-Xminodi phenyl-Skin . 5 -2 - 2-hminoethanol, see E thanolamine. . . . . . . . - 2-Aminopyridine . . . . . . . 0.5 -Ammonia.. . . . . . . . . . . . . 25 Ammonium chloride, fume.. . . . . . . . . . . . . . . - Ammonium sulfamate (Ammate). .......... - n-Amyl acetate.. . . . . . . . 100 sec-Amyl acetate. ...... 125 Aniline -Skin. . . . . . . . . 5 Anisidine (o-, p-isomers) -Skin. . . . . . . . . . . . . . 0.1 Capital letters refer to Appendices. Footnotes (a thru h) see Page 33. 10 3b) mg/m 10 180 25 20 2,400 -70 - 14 0.25 0.3 45 0.25 5 3 22 12 E .lib 2 18 10 10 525 650 19 0.5 .-* Substance ** Antimony & compounds (as Sb).. . . . . . . . . . . . . AXTLT (alpha napht,hyl -1rgon. . . . . . . . . . . . . . . . . ** -4rsenic Q compounds (as -As).. . . . . . . . . . . . . -1sphalt. (petroleum) -1zinphos rnethyl- Skin. Baygon (Propoxur). . . . . Barium (soluble compounds) . . . . . . . . . **C Benzene-Skin. . . . . . . . . Benzidine production - Skin . . . . . . . . . . . . . . . . p-Benzoquinone, see Quinone. . , ... Benzoyl peroxide. . . . . . . Benzyl chloride. . . . . . . . . Beryllium . . . . . . . . . . . . . Biphenyl. . . . . . . . . . . . . . Bismuth telluride. . . . . . . Bismuth telluride (Se-doped) Boron oxide.. . . . . . . . . . . Boron tribromide.. C Boron trifluoride . . . . . . . Bromine. . . . . . . . . . . . . . . Bromine pentafllioride . . Bromoform -Skin. . . . . 3 *) mg/m (0.5) 0.3 - (0.5) 0.2 X la 5 0.2 0.5 0.5 (80) -1lb - 5 5 0.002 1 10 5 10 10 3 0.; 0.7 5 Capital letters refer to A pendices. Footnotes (a thru h) see s a g e 33. **See Sotice of Intended Changes. 11 *- Substance Butachene (1, 3butadiene). . . . . . . . . . . ** Butane. . . . . . . . . . . . . . . . Butanethiol, see Butyl mercaptan. . . . . . . . . . . 2-Bu tanone. . . . . . . . . . . . 2-Butoxy ethanol (Butyl Cellosolve)-Skin.. . . Butyl acetate (n-butyl acetate) ............. sec-Butyl acetate. . . . . . . ten-Butyl acetate. . . . . . ** n-Butyl alcohol-Shn.. . sec-Butyl alcohol. . . . . . . ten-Butyl alcohol. . . . . . C Butylamine-Skin. . . . . C tert-Butyl chromate (as C r a ) - Skin.. ..... n-Butyl glycidyl ether (BGE). . . . . . . . . . . . . . ** Butyl lactate. . . . . . . . . . Butyl mercaptan. . . . . . . ptert-Butyltoluene . . . . . ** Cadmium (Metal dust and soluble salts. asCd) C Cadmium oxide fume (as Cd). . . . . . . . . . . . . . . . . Calcium carbonate.. . . . . Calcium arsenate, as As. Calcium oxide.. . . . . . . . . Camphor (Synthetic). . . Caprolactam Dust. ............... Vapor. . . . . . . . . . . . . . . 3b) mg/m 2,200 (1200) - 590 240 710 950 950 (300) 450 300 15 0.1 270 (5) 1.5 60 (0.2) 0.05 E -- 1 5 2 12 -1 5 20 Capital lettera refer to Appendices. **SeeNot.ice of Intended Changes. 12 1 i I Substance 3)) PPm") mg/m Carbaryl (Sevin") . . . . . . Carbon black. . . . . . . . . . - 5 3.5 Carbon dioxide. . . . . . . . . 5 , W t 9,OOO Carbon disulfide-Skin. 20 60 Carbon monoxide.. . . . . . * Carbon tetrabromide. ... Carbon tetrachloride - Skin.. .............. Cellulose (paper fiber). .. * Cesium hydroxide. . . . . . Chlordane -Skin. . . . . . Chlorinated camphene - Skin. . . . . . . . . . . . . . . . 50 0.1 10 - - - 55 1.4 . 65 E 2 0.5 0.5 Chloriiiated diphenyl oxide. . . . . . . . . . . . . . . . - 0.5 Chlorine. . . . . . . . . . . . . . . 1 3 Chlorine dioxide. . . . . . . . 0.1 C Chlorine trifluoride. . . . 0.1 0.3 0.4 C Chloroacetaldehyde. . . . . 1 3 a-Chloroacetophenone (phenacyichloridel . . . . 0.05 0.3 Chlorobenzene (monochlorobenzene). . 75 350 o-Chlorobenzylidene malononitrile (OCRM) - Skin... . . . . . . . . . . . 0.05 0.4 Chlorobromomethane ... 200 1,050 2-Chioro-1, 3-butadiene see Chloroprene. . . . . . - - Chlorodifluoromethane .. 1,OOO 3,500 ChClohrloodriinpeh)e-nylSk(i4n2.y.0... - 1 Chiorodiphenyl (54% Chlorine) -Skin. . . . . - 0.5 Capital letters refer to Appendices. tSee 1974 +vised Documentation. *I975 Addition 13 Subrtancs 1-Chloro, 2, 3- epoxypropane, see Epichlorhydrin . . . . . . . - 2-Chloroethanol, see Ethylene chlorohydrin. - Chloroethylene, see Vinyl chloride. . . . . . . . - Chloroform (Trichloromethane). . . 25 bis-Chloromethyl ether.. 0.001 1-Chloro-1-nitropropane. Chloropicrin . . . . . . . . . . . Chloroprme (2-chloro-1, 3-butadiene) -Skin. . -* Chlorpyrifos (Dursbans) Skin . . . . . . . . . . . . . * o-chlorostyrene . . . . . . . . 0-Chlorot oluene . . . . . . . . * 2-Chloro-6-(trichloromethyl) pyridine (X- Serves) . . . . . . . . . . . . . Chromates, certain insoluble forms. . . . . . . . . . . Chromic acid and chromates (as CrO3). . Chromium, sol. chromic, * chromous salts as Cr Clopidol (Coyden@). . . . . . Coal tar pitch volatiles (see Particulate Polycyclic Organic Matter (PPOM) . . . . . . . . . . . . - 120 Ala 100 0.7 90 0.2 285 250 10 Ala 0.1 0.5 10 - $Capital letters refer to A pendicm. Footnotes (a thru h) mea age 33. *1975 Additton. 14 Subrtance **Cobalt, metal fume & dust . . . . . . . . . . . . . . *Copper fume.. . . . . . . Dusts and )lists.. . . Corundum (A1203~... . . . Cotton Dust (raw).. . . . Crags herbicide . . . . . . . . Cresol (all isomers! - Skin . . . . . . . . . . . . . . . . Crotonaldehyde . . . . . . . . * CCurumfeonmea-te St kRiund. e.n. es). .... . . Cyanide (asC S )-Skin. Cyanogen . . . . . . . . . . . . . Cyclohexane. . . . . . . . . . . Cyclohexanol . . . . . . . . . . Cyclohexanone. . . . . . . . . Cyclohexene . . . . . . . . . . . Cyclohexyl a m i n e s k i n . Cyclopentadiene . . . . . . . . 2,433.. ............... DDT ................. DDVP, see Dichlorvos. . DDeemcsebtoornaBne--SkSiknin. .. . . . . . . . . Diacetone alcohol (4hydrosy-4-met hyl%pentanoneJ . . . . . . . . . 1, 2-Diaminoethane, see Ethylenediamine. . . . . Diazinon -Skin. . . . . . . Diazomethane . . . . . . . . . . Diborane. . . . . . . . . . . . . . - - - - 5 -2 50 10 300 50 50 300 .1.-0 -1 3 - 0.05 0.01 50 - - 0.2 0.1 ~ Capital letters refer to Appendices. *1975 Addition. *%e Sotlce of Intended Changes. m)see p. 36. i5 (0.1i 0.2 1 E 0.2"' 10 23 G 50 245 5 20 1,030 200 200 1,015 40 200 10 -1 0.3 0.1 240 - 0.1 0.4 0.1 ! Substance 36 ) PPm" mg/m Substance 1, 2-Dibromoethane (ethylene dibromide) -Skin . . . . . . . . . . . . . . Dibrom" . . . . . . . . . . . . . . 2-N Dibutylaminoethanol -Skin. . . . . . . . . . . . . . 2-0 2 145 3 14 Dieldrin -Skin. . . . . . . . -Diethylamine. . . . . . . . . . Diethylamino ethanol -Skin . . . . . . . . . . . . . . . . Diethylene triamine Skin. ............... 25 10 1 -- /a 50 4 Dibutyl phosphate.. . . . . Dibutylphthalate ....... C Dichloracetylene . . . . . . . -1 0.1 5 5 0.4 Diethylether, see Ethyl ether. ............... - Diethplphthalate. . . . . . . * - - 5 C o-Dichlorobenzene.. . . . . 50 pDichlorobenzene.. . . . . Dichlorobenzidine- Skin . . . . . . . . . . . . . . . . 75 - Dichlorodifluoromethane. 1,000 1,3-Dichloro-5, 5- dimethyl hydantoin. .. - 300 450 Alb 4,950 0.2 Difluorodibromo- methane. . . . . . . . . . . . . C Diglycidyl ether (DGE). Dihydroxybenzene, see Hydroquinone . . . . . . . Diisobutyl ketone. . . . . . Diisopropylsmine - 100 0.5 - 25 860 2.8 150 1, 1-Dichloroethane.. ... 200 820 Skin . . . . . . . . . . . . . . . . 5 20 1, ZDichloroethane.. . . . -1, 2-Dichloroethplene . . . Dichloroethyl ether Skin. ............... 50 200 5 200 790 30 Dimethoxynethane, see -Methylal. . . . . . . . . . . . Dimethyl acetamide skin . . . . . . . . . . . . . . . . 10 - 35 Dichloromethane, see Methylene chloride. . . Dichloromonofluoro- - - Dimethplamine . . . . . . . . Dimethylaminobenzene, see Xylidene.. . . . . . . . 10 - 18 I methane. . . . . . . . . . . . . 1,OOO C 1, 1-Dichloro-lnitmethane . . . . . . . . . . 10 4,200 60 Dimethylaniline (S- dimethylaniline) - Skin . . . . . . . . . . . . . . . . 5 5.2 1,2-Dichloropropane, see Propylenedichloride.. . - - Dimethylbenzene, see Xylene. . . . . . . . . . . . . . - - Dichlorotetrafluoro- Dimethyl 1, 2-dibromo- -ethane. . . . . . . . . . . . . . 1,OOO 7,000 Dichlorvos (DDVP) I Skin.. .............. 0.1 1 i *Dicyclopentadienyl- iron. ................ - 10 i Capital letters refer to A pendicea. Footnotea (a thru h) ~ e beage 33. *1975 Addition i 16 ' 2 - d i c h l o ~ t h y l phos- -phate, see DiBrom.. .. Dimethylformamide skin ................ 2, GDirnethylheptanone, see Diisobutyl ketone. 17 - 10 - - 30 - Substance 36) mg/m Substance PPma) 1, 1-Dimethylhydrazine -Skin. . . . . . . . . . . . . . Dimethylphthalate. . . . . -2, 3-Epoxy-1-propanol, 1 see Glycidol.. ....... 5 Ethane. ............... F ** Dimethyl sulfate-Skin. Dinitrobenzene (all isomers) -Skin. . . . . . (W 1 -Ethanethiol, see Ethvlmercaptan.. .... Ethanolamine.. . . . . . . . . . 3 DinitrM>-cresoi - Skin. 0.2 2-Ethoxyethanol-Skin. 100 * 3,5-Dinitro-o-toluam- 2-Ethoxyethylacetate ide (Zoalenea) . . . . . . . Dinitrotoluene -Skin. . Dioxane, technical grade --Skin. . . . . . . . . . . . . . Diphenyl, see Biphenyl. . Diphenyl amine. . . . . . . . 5.0 (Cellosolve acetate) 1.5 -Skin .............. 100 -Ethyl acetate.. ........ 400 1-80 Ethyl acrylate Skin. .. 25 Ethyl alcohol (ethanol). . 1,OOO 10 Ethylamine . . . . . . . . . . . . 10 Diphenylmethane diisocyanate , see Methylene bisphenyl isocyanate (MDI) . . . . Ethyl sec-amyl ketone (5 methyl3-heptanone) . . 25 - Ethyl benzene.. ........ 100 Ethyl bromide.. ....... 200 Dipropylene glycol methyl ether - Skin. Ethyl butyl ketone (3- 600 Heptanone) .......... 50 Diquat. . . . . . . . . . . . . . . . 0.5 Ethyl chloride.. ........ 1,OOo I Di-sec, octyl phthalate ! (Di-2-ethylhexyl- Ethyl ether.. .......... 400 Ethyl fomte......... 100 ! phthalate) . . . . . . . . . . . 5 Ethyl mercaptan. ...... 0.5 1 ; Disys t o n 4 k i n. . . . . . . . . 0.1 Ethyl silicate. ......... 100 * 2,6-Ditert-butyl-p-cresol Emery. ............... 10 E * * Ethylene Ethylene .............. chlorohydrin - F f Endosulfan (Thiodan@) -Skin. . . . . . . . . . . . . . -0.1 Skin. ................ Ethylenediamine ....... (5) 10 -! Endrin Skin. ........ 0.1 Ethylene dibromide, tee ! -? Epichlorhydrin -Skin. . EPN -Skin. .......... " *,19 0.5 -1,2-Dibromoethane. - . Ethylene dichloride; %ee J< -I 1, 2-Epoxypropane, see ,. 1, BDichloroethane.. Propylene oxide.. .... Capital letters refer to Appendices. *1975 Addition. **See Notice of Intended Changa. c - Ethylene glycol, particu- late......I ; . ........ -, - **see Notice of ~nte;lded.-. Capitd lettan referto Appmdioaa ... '10 18 19 ' - Ethylene glycol, vapor.. C Ethylene glycol dinitrate -and/or Nitroglycerin- Skin. ............... 100 0.W 260 2- Ethylene glycol mono- methyl ether acetate (Methyl cellosolve ace- tate)-Skin. ........ 25 120 Ethylene oxide. ........ 50 Ethylenimine -Skin. . . 0.5 90 1 Ethylidine chloride. Bee 1, 1-Dichloroethane.. . - - C Efhylidene norbornene.. 5 25 N-Ethylmorpholine - skin ................ Ferbam ............... Ferrovanacfium dust. ... Fluoride (BS F). ........ Fluorine. .............. -20 - - 1 94 10 1 .2.5 2 Fluorotrichloromethane. 1 C Formaldehyde. ......... 2 * Formamide. . . . . . . . . . . . 20 Formic acid.. .......... 5 Furfural-Skin. . . . . . . . 5 5,600 3 30 9 20 Furfuryl alcohol.. . . . . . . Gasoline. .............. -5 20 B' Germanium tetrahydride GGllayscse.rfiinbrmoui ssta.).o.r .d.u.s.t...... 0-.2 . 0.6 E -..E Glycidol (2, 3-E~ox~-1- -.-.-prop~n~l.)...... . Glycol monoethyl .ether, . . 50 -8 --seeZEthoxyethad.. 11 . - I -. . 150 t' + I . I ' l Capital letters refer to A pendim. Footnota (athru h) BBB sage 33. *la76Addition, ..a 20 +' !i Substance Graphite, (Synthetic). .. Guthion,@ see Azinphos- methyl. ............. Gypsum. .............. Hafnium. ............. Helium. ............... Heptachlor-Skin. .... ** Heptane (n-heptane).... Hexachlorocyclopenta- -diene . . . . . . . . . . . . . . . Hexachloroethane skin . . . . . . . . . . . . . . . . He-wLSckhilno.r.o.n.a.p.h.th.a.l.e.n.e. . Hexafluoroacetone...... ** Hexane (n-hexane)...... ** 2-Hexanone (Methylbu- tyl ketone) -Skin... Hexone (Methyl isobutyl ketone) -Skin. ...... -sec-Hexyl acetate.. . . . . . **Hydrazine Skin. ..... Hydrogen ............. Hydrogen bromide.. .... C Hydrogen chloride.. . . . . Hydrogen cyanide- skin ................ Hydrogen fluoride. ..... Hydrogen Hydrogen speelreonxididee. .......... HHyyddrroogqeuninsounlefi.d.e.............. Indene ................ Indium and compounds, **&Ca itall+temrefertoAp ndices.' Nofice of Intended &mges. 21 .'-Is c Substance C Iodine. ............... * Iron Iron oxide fume. . . . . pentacarbonyl.. ...... Iron salts, soluble, Isoamyl acetate.. .a.s.F.e... Isoamyl alcohol. . . . . . . . Isobutyl acetate.. ...... ** Isobutyl alcohol. . . . . . . . ** Isophorone . . . . . . . . . . . . Isopropyl acetate. . . . . . . Isopropyl a l c o Isopropylamine h. o. .l .4.k.k... Isopropyl ether. . . . . . . . 0.1 B' 0.01 - 100 100 150 (100) (10) 250 400 5 250 1 5 0.08 1 525 360 700 (300) (50) 950 980 12 1,050 IKKsoae(otpIerlCnionEep..y)...l.....g...l.y...c...i...d...y...l.....e...t..h...e...r.. . -50 0.5 Lead, inorg., -dusts, as P bf.u.m.e.s..a.n..d -LLLeiimnaddeasantroesn-een.Ss.ktie.n,.a..s..P.. b. ........ ..... . . - Lithium hydride. . . . . . . . - 240 E 8 0.9 0.15 0.15 E 0.5 0.0% -L.P.G. leum g(Lasiq).u.if.i.e.d. .p.e.tr.o.-. 1,OOO MMaaggnneessiiutem. ........... oxide fume. .. - -Malathion -Skin. ..... Maleic anhydride.. . . . . . 0.25 1,800 E 10 , 10 1 -CManganese and com- pounds, as M n . . . . . . . 5 Manganese cyclopenta- d(aiesnMylnt)ri-cSakrbi non. .yl...... - '1 0.1 Capital letters d e r to Appendices. *1975 Addition. -See Notice of hwded Chan&:'.: . --.-- " ,. ... _-,_.'c_- -- 22 _ . Marble. ............... - Mercuv (Alkyl com- pounds) -Skin. as Hg 0.001 iMercury (All cept alkyl) afsorHmgs. .ex. -. - Mesityl oxide. . . . . . . . . . 25 Methane. ............. F Methanethiol, seeMethyl mercaptan. .......... Methoxychlor. . . . . . . . . . - 2-Methoxyethanol-Skin M.e(Mthyelthayclectaeltleo.s. o.l.v.e.) ...... 25 200 Methyl acetylene (pro- pyne). .............. 1,OOO Methyl acetylene- p(Mro,p4aPdPie)n.e. .m. i.x.t.u.r.e. . . 1,000 -Methyl acrylate -Skin . Methyl acrylonitrile 10 1 skin ................ Methylal (dimethoxy- methane). ........... 1,ooO Methyl alcohol (methanol)-Skm. . . . . . . . . . . 200 Methylamine . . . . . . . . . . 10 Methyl amyl alcohol, see Methyl isobutyl carbi- - no1 . . . . . . . . . . . . . . . . . Methyl 2-cyanoacrylate. 2 Methyl isoamyl ketone. . 100 Methyl n-amyl (2-Heptanone) . .k.e.to. n. .e Methyl bromide -Skin. Methyl butyl ketone, see 2-Hexanone. ......... 100 15 - Copital letters refer h Appendices. 23 E 0.01 0.05 100 - - 10 80 610 1,650 1,800 35 3 3,100 260 12 8 415 465 60 - i-l ., . *,. . ..... i,; . . . . . . . I. . ........... ". __ .. _ _ Ii Substance )'3 a*) ms/m -Methyl cellosolve Skin see ZMethoxyethanol. -m s l m Subrtcmc. a Ca-Methyl styrene. ...... PPmd 100 i C Methylene bisphenyl iao- 480 Methyl celIosolve acetate -Skin, see Ethylene cyanate.(MDI). ....... **Methylene chloride (di- 0..02 0.2 glycol monomethyl -ether acetate.. ....... Methyl chloride. ....... 1 - .Methyl chloroform. .... ** Methylcyclohexane..... Methylcyclohexanol. . . . 235 1o-Methylcyclohexamm ---skin... ........... Methyicyclopentadienyl -manganese tricarbodyl (aa Mn)-Skin.. .... iMethyl demeton -Skin. Methyl ethyl ketone .. 1(MEK), isee ZBU- .;.-tanone ........... f -C Methyl ethyl ketone peroxide.. . . . . . . . . . . . 0.2 _-Methyl formate.. . . . . . . . 100 -Methyl iodide Skin. . . 5 210 1*900 (zooo) 0-2 1.5v:. . 250 . ' ' 28 chloromethane). ..... (100) (360) 4,4'-Methylene bk (2- ehloraniline)+kin. 0.02 CMethylene bis ( k y & . A2 hexylisocy~te).... 0.01 Mdybdenum,a~Mo Soluble compaunds. .. -1neoluble compounds. 0.11 5 10 Monomethyl skin...... ....anilin~e . ... i.. 2 9 CMonomethyl h y u e -8kin.:.*~. ......... 0 2 0.35 Mwholine- Skin .......... #) 70 Naphthalene........... 10 BNNeospnh..th..-e:................... . -. F . 50 Alb ** Nickel carbonyl.. ..... (0.001 Ala)(0.007) Nickel, metal and insol- M-e-tshk-yin_l..i.sobu.t.y.l.c.a.r.b.i.n.o.l 25 -. *<.lo0 -- -MesetheyHl eixeoonbeu.ty.l..k.e.t.o.n.e.. Meth.yl isocyanste Slun ................ - --_ .I/ .. .Methyl Methyl mercaptan.. .. methacrylate.. i.. Methyl parathion+3kin. -Methyl propyl ketone, see %Pentanone. . ... CMethyl ailicate. ._..J... 24 Substance 30 PPm3 mg/m Substance 36) PPm" mg/m C Nitrogen dioxide. . . . . . . Nitrogen trifluoride. . . . . Nitroglycerind) -Skin. . Nitromethane .......... l-Xitropropane ......... 2-Nitropropane. . . . . . . . . 5 10 0.2 100 25 25 9 29 2 250 90 90 N-Nitrosodimethylamine -(-dimSkeitnh.y.ln. .it.r.o.m. .a.m.i.n.e.) Nitrotoluene -Skin. ... 5 - A2 30 Nitrotrichloromethane, see Chloropicrin.. .... - Nitrous oxide.. ........ - F - Octachloronaphthalene -Skin. . . . . . . . . . . . . . * * Octane. . Oil mist, ........... particulate. ...... Oil mist, vapor.. . . . . . . . - (4-00) dB2 0.1 (1,900) -Y' Osmium tetroxide, as Oxalic acid. . . . . . . . . .O.s.O.OOO-2 Oxygen difluoride. . . . . . . 0.05 Ozone.. ............... -* PPaarraaqfiunatwaxSfkuimn.e.. ..... ..... Parathion -Skin. . . . . . . 0.1 --- 0.002 1 0.1 0.2 2 0.5 0.1 Particulate polycyclic or- agsanbiecnzmenaettesrolu(PbPleOs.M. .) Pentaborane . . . . . . . . . . . 0.005 0.2 0.01 -Pentachloronaphthalene Skin. ............. -Pentachlorophenol skin.. . . . . . . . . . . . . Pentaerythritol......... -- Capital lettera refer to A pendioee, Footnotes (athru h) seeBa e33. **See Notice of Intended-CLea .-0.5 0.5 E - ., 26 **Pentane. . . . . . . . . . . . . . . 2-Pentanone . . . . . . . . . . . PerchloroethvleneSkin . Perchloromethy1 mercaptan. . . . . . . . . . . Perchloryl fluoride.. . . . . Petroleum Distillates (naphtha). . . . . . . . . . . Phenol -Skin. . . . . . . . . -Phenothiazine -Skin. .. pPhenylene diamine skin . . . . . . . . . . . . . . . . Phenyl ether (vapor).... Phenyl ether-Diphenyl mixture (vapor)...... Phenylethylene, see Styrene . . . . . . . . . . . . . Phenyl giycidyl ether -(PGE) . . . . . . . . . . . . . . Phenylhydrazine Skin. C Phenylphosphine . . . . . . . Phorate (Thimet@)--Skin Phosdrin (Me vinp hosa) -Skin.. . . . . . . . . . . . . ** Phosgene (carbonyl chloride) . . . . . . . . . . . . . . . . Phosphine. . . . . . . . . . . . . Phosphoric acid. . . . . . . . Phosphorus (yellow). . . . Phosphorus pentachlo- ride. . . . . . . . . . . . . . . . . Phosphorus pentasuifide. . Phosphorus trichloride. . ** Phthalic anhydride. .... Capital letters refer to Ap dim. **See Notioe of Intended %angm. n (1,500) 700 670 0.8 14 - 19 5 0.1 c I 7 - 60 22 0.25 0.05 0.1 (0.4) 0.4 1 0.1 1 1 3 (12) ._,.- . ....... t t , _.* Substance *Picloram (Tordon@).. . . 3*) apofm 10 36) Substance PPme' ms/m Ronnel. ............... - 10 Picnc acid-Skin. . . . . . 0.1 Rosin Core Solder PiVal@ (ZPivalyl-l,3- indandione).......... Plaster of Paris.. ....... Platinum (Soluble Salts) . .pyrolysis products (as -0.1 formaldehyde)....... --E Rotenone (commercial). Rouge. ............... 0.1 5 E 88 Pt.. .............. Polychlorobiphenyh, see Chlorodiphenyls.. .... 0.002 - Selenium compounds (88 Se) ................. - Selenium hexafluoride, as 0.2 Polytetrafluoroethylene decomposition prod- se................... Sevin@(see Carbaryl). .. 0.0-5 0-.4 ucts.. .............. 8 C1,PP3roPotraposapsniiueo.ml.ac.ht;oy.nd.er.o..x..i..d..e............ B' -2 A2 S i n e (see Silicon tetra- hydride). ............ Silicon. ............... Silicon carbide. ........ - - - E E Propargyl alc0hoHki.n. n-Propyl acetate. ...... Propyl alcohol-Skin ... n-Propyl nitrate.. ...... 2 Silicon tetrahydride 840 (Silane) ............. 0.5 0.7 500 110 Silver, metal and soluble compounds, as Ag. ... - 0.01 Propylene dichloride (1, ZDichloropropane) . . . 350 Propylene glycol mono- -methyl ether.. ....... Propylene imine Skin. Propylene oxide.. ...... 360 5 240 - _ -P.raocpeytynlee,nes.e.e..M..e..th..y.l.- Pyrethrum. ........... -.I 5 - .QFR'yDumiXndoinnee.S...k..i..n.........................-...... :5 0-.1 . 15 .a4 1.5 Rhodium,---Metal:L fume , b; d SFnt&r deu&atadl(mtaR.h.)...;...i . 1 -. - a s 0.1 0.001 * Sodium fluoroacetate (1080) -Skin. ....... C Sodium hydroxide. . . . . . Starch. ............... Stibine. ............... ** Stoddard solvent. ...... Strychnine. ............ --- 0.05 2.0 E 0.1 0.5 (2-00) (11%) 0.15 Styrene, monomer (Phenylethylene) . . . . 100 420 'C Subtilisins (Proteolytic emymee as loocY, pure .... -succrroysseta..ll.in.e..e.n.z*y..:m. e). .. - O.ooOo6'' E SSutiliffuwrhdeixoaxfidlueo..ri.d.e........... 5 1,OOO 13 6,000 latftprrefer to A dices. %E?LsBom-J&. L'3,'. ' 5 1 r n W ~ X i,, I , .- . e: .a. *h . Captd lettae refer to A p p d i c e a *I975Addition. *+See Notice uf btendd Changes. - 0 ) k p. 38. ' -% 29 Sulfuricacid.. ......... - Sulfur monochloride. Sulfur pentafluoride.. ...... 1 0.025 Sulfur tetrafluoride. . . . . 0.1 1 6 0.25 0.4 Sulfuryl fluoride.. . . . . . . 5 20 - -Systox, see &meton@. .. -2,4,5-T.. ............. 10 -TTaEnDtaPlu-mS. k.i.n.,....... . . . . . . . . . . - 5 0.2 1 Teflon@ decomposition -products.. ........... B' -Tellurium . . . . . . . . . . . . . 0.1 31 t i Tellurium hexafluoride, as Te. . . . . . . . . . . . . . . 0.02 TEPP -Skin.. ........ 0.004 0.2 0.05 I C Terphenyls. ........... 1 9 1, 1, 1, 2-Tetrachloro-2, ! 2difluoroethane. ..... 500 4,170 1, 1, 2, 2-Tetrachloro-i, i' t 2difluoroethane.. .... 500 4,170 1, 1. 2, 2-Tetrachloro- i' -ethane Skin. ....... 5 35 I Tetrachloroethylene, see i - -Perchloroethylene. . . . 1 Tetrachloromethane, see - -Carbon tetrachloride. . Tetrachloronaphthalene 1 - -skin.............. i Tetraethyl lead (as Pb) 2 --skin... ........... I Tetrahydrofuran ....... 200 Tetramethyl lead (asPb) i - -f skin. ............. Tetramethyl succinoni- i i ! tde-Skin.. ........ 0.5 - . .i Capital lettern refer to A pendices. i i Footnotes (a thru h) see gage 33. I 30 I Substance P P ms~/m 3~b) Tetranitromethane.. .... r 1 8 Tetryl (2.4, 6- trinitrophenyl- .-. -methylnitramine) . Skin.. .............. - 1.5 Thallium (soluble, corn- -pounds+Skin(ssT1). :. -Thiram@......... ...... * 0.1 5 Tin (inorganic -corn- - ... -pounds, except SnH, and SnO2) as Sn.. 2 Ti-nSk(oinrgan(iacscSonm).p.ou.+n.. ds..) ......*. . --TTiintanoxiuidme.d. i.o.x.i.d.e.. ..,. -' ~ 0.1 E E Toluene (toluol) -Skin. 100 375 C Toluene-2, 4- diisocyanate (TDI). .- - .+Toluidine. .- .- ..-% . Tonxaatpehdencaem, paheeeneC..h.lo.r.i-. -Tributyl phosphate. . - . r 0.02 5 -- 0.14 . 22 - 5 -1, 1, l-Trichlon>ethsn~ seeMethyl chloroform. - 1, 1, ZTrichloroethane >-skin.............. 110 . 45 Trichloroethylene.. ..... 100 535 -Trichloromethane, see . Chlorofom.. ........ -'-- . I' -31 35 i1 I i 1. tr- I `i Substan- PPm" * Tricyclohexyltin hy- droxide (Plictran@)... Trifluoromonobromo- methane. ............ Trimethyl bensene.. .... 2,4, &Trinitrophenol, see -Picric acid.. ......... 2, 4, 6 Trinitrophenyl- TrmTineeitttrrhoyytllon.l.iut.ne.rnm.e.-i.n.e.S, .k.i.ns.e. .e. Triorthocresyl phosphate ........... Triphenyl phosphate.. . . Tungsten & compounds, aSW Soluble. ........... TurpZennstoinlueb.le..................... Uranium (natural) soluble & insoluble com- pounds, a. U......... vvanadium (VZOS),as Dust. ............... C Fume. ................ V i y l acetate.. ........ Viiyl benzene, see Sty- rene. ............... Viiyl bromide. ........ +*Vinylchloride. ......... ViAnyclryclyoanniitdriel,e..w.e....... Vinylidene chloride. ..... Vinyl toluene.. ........ Warfarin .............. 3') m!dm 5 6,100 120 - - 1.5 0.1 3 1 5 560 0.2 0.5 0.05 30 - 1,100 (510) *- 40 480 - 0.1 . Wood dust (nonallergenic). . . . . . . Xylene (o-,m-,p-isomers) -Skin.. . . . . . . . . . . . . Xylidine -Skin. ....... Yttrium.. ............. Zinc chloride fume.. ... Zinc oxide fume. . . . . . . . Zinc stearate.. . . . . . . . . . Zirconium compounds (as Zr). . . . . . . . . . . . . . - 5 5 a) Parts of vapor or gas per million parts of contaminated air by volume a t 25C 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 p m in diameter. f ) As sampled by method that does not collect vapor. g) According to analytically determined composition. h) For control of general room air, biologic monitoring is essential for personnel control. Rrrdiocrdisrily: For permissible concentra- tions of radioisotopes in air, see US. De- partment of Commerce, National Bureau of Standards Handbook 69, ``MaximumPer- missible Body Burdens and MercimumPer- missible Concentrations of Radionuchdw in Air and in Water for Occupational Kpo- `-..sure," June 5, 1969. Also, see U.S.Depart ment of Commerce Nationsl -BtiSa;u::of _. .,-5- &> t Standards, Handbook 59, "PermissibleDose from External Sources of Ionizing Radiation,'' September 21. 1954, and addendum of April 15, 1958. A report, Basic Radiation Protection Criteria, published by the National 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. 2O008. MINERAL DUSTS Substance , I I I SILICATES ( < 1% quartz) Asbestos, a11 formst Graphite (natural) Mica Mineral wool fiber Perlite Portland Cement ' Soapstone Talc (nonasbestifom) Talc (fibrous) use hbestos limit. 5 fibersjcc> 5rm in Ikngth"); A l a 15 mppcf 20 mppcf 10 mgjm3 30 mppcf 30 mppcf 20 mppcf 20 mppcf SILICA, Si02 Tremolite, see Asbestos. Crystalline COAL DUST . Quartz TLV in mmcf J : -3w' +% quartz 10 i (bituminous). 2 mg/m* (respirable dust fraction < 5% quartz). .t If> 5% quartz, use respirable I, TLV for respirabIe dust rnrtss formula. iin mg/m': NUISANCE PARTICULATES I +10 mg/mak' i % Respirable quartz 2 -1 (see Appendix E) 30 m p p c f or 10mg/mal) TLV for "total dust,'' res- ; of total dust < 1% quartz pirable and nonrespirable: ' Conversion factors: + !i 30 mg/m' % quartz 3 I Cristobalite. ....Use one-half the value cal- mppcf X 3.5..3 = million particles per cubic meter = partides per C.C. culated from the count or i) Millions of particbs per cubic foot of air, _. mam formulae for quartz. based on impinger samples counted by -TIidpite - Use onehalf the vaiue calculated from formulae light-field technics. 'j) The pedentage of quartz in the formula use quartz formulae. ' .- -- -" * I ' :qUusaertzref8orpmirualbaleP) mas8 .vhOE(d:.. . ..,:. ... .......~..20 mppcf'? ...i Notice of Intended Changee. ia the amount-determined from airborne samples, except in those instances in which other-methods have been shown to be applicable. I tA-more stringent~.TLVfor crocidolite may be * required. 1) n) Sea p. 36, 34 35' k) Both concentration and percent quarts for the application of thia limit are to &*NOTICEOF INTENDED CHANGES (for 1975) be determined from the fraction passing a size-eelector with the following characteristics: These substances, with their corresponding values, comprise those for which either a limit has been proposed for the first time, Aerodynamic Diameter (pm) (unit density sphere) ?2 2.5 3.5 5.0 10 % Pa=@ selector -90 75 ./ --~ 50 25 ~ 0 or for which a change in the "Adopted" listing haa been propod. In both c&8e8, the proposed limits should be considered trial limits that will remainin the listing for a period of at least two years. If, after two yeam no evidence mmes to light that qua- tions the appropriateness of the d u e s herein, the values will be reconsidered for the "Adopted" list. Documentation ia 1) containing <1% quartz; if quartz con- available for each of these eubstances. I i tent > l%,use formulae for quartz. Substance PPm=' mg/m 3 4 i i1 -5 ! m) Lint-freedustasmeasuredby the vertical- elutriator, cottondust ssmpler described in the Transactions of the National Con- ferenceon -Cotton Dust, 3. R. Lynch, pg. 33,M a y 2,1970. n) As determined by the membrane filter method at 4oo-45oX magnification +Antimony trioxide, ban- <dling&use,asSb....... - +`Antimony trioxide pro- duction. ....... .... " A 2 +Arsenic troxide, handling &use ................ `Arsenic trioxide produc- 0.5 0.05 0.25 (4 mm objective) phase contrast iIlumi- tion ................... Ala 0.05 nation. +Benzene-Skb .......... 1OA2 30 0 ) B a d on "high volume" sampling. +Borates, tetra, sodium p) "Respirable" dust aa defined by the -British Medical Research Council Cri- salts..:.: ............ . Anhydrous........... 1 teria (I) and aa sampled by a device Dewhydrate .*. I 5 producing equivalent resuIta [2). ' (1) Hatch, T. E. and-G&%P., :&Imonary 'Deposition tgd ae`teption of -. Inhaled Aerosols; p."f49. `JAcademic Press, New York, flew Yo&,"1964. (2) Interim Guide`far Respirable Mase Sampling, AIHA A e r o d Teohaoiogy Committee, AHIA J. 31: p. 133. _c 36 37 Substance PPm" Calcium hydroxide. . . . . . Captan. . . . . . . . . . . . . . . . - + Captafol (Difolatan") - ........ L Carbofuran . . . . . . . . . . . . . - + Catechol (Pyrocatechol).. 5 + Chromite ore processing (as CrO3). . . . . . . . . . . . . A-la Skin... . . . . . . . . . . . . . . Dicyclopentadiene. . . . . . . +C Dimethyl sulfate. . . .'. . . . + Dioxathion (DelnavB). . . . - 5 -1 + Diuron.. . . . . . . . . . . . . . . . D-donate. . . . . . . . . . . . . . . Ethion (Xialates)-Skin. C Ethylene chlorohydrin - Skin. . . . . . . . . . . . - Fensulfothion (Dasa Formamide . . . . . . . . . . . . . 20 C Glutaraldehyde.. . . . . . . . . 2 C Glutaraldehyde (Alkaline - Heptane. . . . . . . . . . . . . . . . 400 Hexane . . . . . . . . . . . . loo 2-Heuanone (Methyl butyl .. ketone). . . . . . . . . . . . . . . 25 C Hexylene glycol. . . . . . . . . 25 + Hydrazine. . . . . . . . . . . . . . 0.1 Hydrogenated terphenyls 0.5 Iodoform. . . . . . . . . . . . . . . 0.2 Isobutyl alcohol. . . . . . . . . 50 C Isophorone . . . . . . . . . . . . . 5 Capital letters refer to Appendices. +1975 Addition or Revision. 38 0.1 0.1 20 0.1 2 0.25 30 A2 0.2 2 10 0.1 0.4 3 0.1 30 8 0.23 1,600 360 100 125 0.1 5.O 3.0 150 25 Substance 3*) P P ~ " ) ms/m Isophorone diisocyanate- Skin. . . . . . . . . . . . . . . . . 0.01 + Methomvl (Lannates) - 0.06 Skin.. . . . . . . . . . . . . . . . - 2.5 3Iethylcyclohexane. . . . . . 400 1,600 Methyiene chloride (Di- chloromethane) . . . . . . . 200 720 +Monocrotophos (Xzo- drina)................. Sickel, soluble salts(asSij - 0.25 0.1 + Sickel carbonyl. . . . . . . . . 0.05 Sonane . . . . . . . . . . . . . . . . 200 Octane. . . . . . . . . . . . . . . . . 3 0 0.35 1,050 1,450 Pentane. . . . . . . . . . . . . . . . 600 1,800 C Phosgene. . . . . . . . . . . . . . . 0.05 0.2 + Phthalic anhydride.. . . . . 1 + m-Phthalodinitrile. . . . . . . - +C 1, 2-Propylene glycol dini- trate -Skin.. . . . . . . . . 0.05 Resorcinol. . . . . . . . . . . . . . 10 + Rubber Solvent. . . . . . . . . 400 6 3 0.33 45 - C Sodium azide. . . . . . . . . . . 0.1 0.3 Stoddard Solvent.. . . . . . . 100 175 Succindialdehyde (see Glutaraldehyde). . . . . . . - 4. -l'-Thiobis (6-tert butylm-cresol). . . . . . . . . . . . . - 10 C 1, 2, 4-Trichlorobenzene.. j Triphenylamine . . . . . . . . . - 40 5 Vinyl chloride. . . . . . . . . . .Pending Alc + Vinyl cyclohexene dioxide. 10 + V1.X & P Saphtha.. . . . . . . 200 60 - Welding fumes (Total Particulate). ........... C m-Xylene a,a' diamine.. . + Zinc chromate. s Cr03.. - 5 & B4 0.1 0.1 Capital letters refer to Appendices. +1975 Addition. 39 NOTICE OF INTENDED CHANGES (Cont'd) MINERAL DUSTS Substance TLV + Silica, amorphous (in- 3 mg/m* Total cluding natural Diato- dust (all sam- maceous Earth) pled sizes) 1 mg/m* Res- pirable dust (<5w) APPENDIX A Occupational 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 three forms, those for which a TLV has been assigned (la), those for which environmental conditions have not been sufficiently defined to assign a TLV (lb), and IC,those whose reassignment of a TLV is awaiting more definitive data, and hence should be treated as a 1b carcinogen. la. Human Carcinogens. Substances, or substances associated with occupational processes, recognized to have carcino- -genic or cocarcinogenic potential, with an assigned TLV. Arsenic trioxide production TLV As&, 0.05 mg/mg as As S&, C 5.0 ppm S b h , 0.05 mg/ma as Sb 40 Asbestos, all forms* 5 fiberslcc, > 5~ in length Cadmium oxide production 0.05 mg/ma as Cd bis (Chloromethyl) ether 1.0 ppb Chromite ore processing 0.1 mg/m*as Cr03 Particulate Poly- , cyclic Organic 0.2 mg/ma, as ben- Matter zene solubles Ib. Human Carcinogens. Substances, or substances associated with industrial processes, recognized to have carcinogenic potential without an assigned TLV: 4-Aminodiphenyl (p-Xenylamine) Benzidine production -Skin beta-Xaphthylamine 4-Sitrodiphenyl IC. Human Curcinogens. Substances with recognized carcinogenic potentid awaiting reassignment of TLV pending further data acquisition : Vinvl chloride 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 process or operation by the best practicable engineering methods. The worker should be properly equipped to insure virtually no contact with the carcinogen. *Cigarette smoking m y substantislly enhance the incidence of bronchogenic carcinoma from this and others of these listed substances or processes. 41 A2. Occupational Substances Suspect qf Oncogenic Potential for Workers. Chemical substances, or substances associated with occupational processes, which are suspected of inducing malignant neoplasms, based on either a) limited epidemiologic evidence, exclusive of clinical reports of siigle cases, or b) demonstration of benign or malignant growths in one or more animal speciesby appropriate methods. ~ /' Present evidence indicates that the assigned TLVs are below the threshold of response for inducing cancer in workers under ordinary conditions of employment. For those substances without an assigned TLV, exposure by all routes should be carefully controlled to levels consistent with the animal and human experience data (see Documentation). Substance or .Operotion TLV Antimonp trioxide productiona) 0.05 mg/ma Benzenea) 10 PPm Benzo(a)pyrenea)-Skin 2.0 p g / m a 3,3' Dichlorobenzidineb) --Skin Dimethyl sulfateb) Hydrazineb)-Skin c 1.0 ppm 0.1 ppm -4, 4'-3fethylene bis (2-chloroaniline)' Skin 0.02 ppm 42 Nickel production (Ni3Sz)"'b' Nitrosamines (Dimethyl nitrosamine)' Propane sultoneb) beta-Propiolactoneb) Zinc Chromate) 0.1 mg/m3as CrOa Letters in wnthesea refer to kinds of informational bases qua&in~ the substance or operauon to be included in -42. (See Documentation) APPENDIX B B1 Polytetrafluoroeth ylene* decmnpodwn produd?. Thermal decomposition of the fluorocarbon chain in air leads to the formation of oxldized products containing carbon, fluorine and oxygen. Because these products decompose in part by hydrolysis in alkaline solution, they can be quantitatively determined in air as fluoride to provide an index of exposure. pu'o TLV is recommended pending de- termination of the toxicity of the products, but air concentrations should be minimal. B* Gasoline. The composition of gasoline variea greatly and thus a single TLV for all types of these materials is no longer applicable. In general, the aromatic hydrocarbon content will determine what TLV applies. Consequently the content of benzene, other aromatics and additives should be determined to amve a t the appropriate TLV (Elkins, et sl. A.I.H.A.J. 2$:99, 1963); Runion, ibid. 96, 338, 1975) *Trade Names: AlgoAon, Fiuon, Halon, Teflon, Tetran. 43 B' Petroleum DLd.h&8. For petroleum distillates for which no specific TLVs are listed, approximate values can be obtained by use of the following equation: TLV = 100 + +. 3.6(200 - B.P."C.) 20 +?& Ar 1.3(200 - B.P."C.) 10PPm where .U = aliphatic component Ar = aromatic component B.P. = mean boiling point in de- grees centigrade (normally the joT0distillation tem- perature). The equation cannot be used if the benzene content of the fraction exceeds 1%, nor if the mean boiling point is above 200C. 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 approximated by the following equation : + +M.W. = %AI 0.88%h -OS(B.P."C. 100) B' Welding Fumes - Total Partiadate ( N O C )* TLV, 5 rnglm' Welding fumes cannot be classifiedsimply. The composition and quantity of both are dependent on the alloy being welded and the *Not otherwise classified. 44 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. Similar processes are used to arc-weld steels, also creating a relatively low level of fumes. Ferrous alloys also are arc-welded in oxidizing environmenta 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 constituents 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 formulated with fluoridesand the fumes associated with them can contain significantly more fluorides than oxides. Because of the above factors, arc-welding fumes frequently must be tested for individual constituenfs which are likely to be preaent to determine whether specific TLV'a are exceeded. Conclusions based on total fume concentration are generally adequate if DO toxic elements are present in welding rod, metal, or metal coating and conditionsare not conducive to the formation of toxic gases. Most welding, even with primitive ventilation, does not produce exposum inside the welding helmet above 5 mg/ma. That which does, should be controlled. 45 APPENDIX C C.l THRESHOLD LIMIT VALUES FOR iMIXTURES 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, -9 +-e2 +...-C, Ti T2 T, exceeds unity, then the threshold limit of the mixture should be considered as being exceeded. CI indicates the observed atmospheric concentration, and TI the corresponding threshold limit (See Example 1A.a. and ? 1A.c.). Exceptions to the above rule may be made i when there is 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 on 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 member of + +(3the series or TI a value exc&ng unity (See Example 1A. c.). Antagonistic action or potentiation may occur with some combinations of atmospheric contaminants. Such cases a t present must be determined individually. 46 Potentiating or antagonistic agents are not necessarily 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 characteristically exhibited a t high concentrations, less probably a t 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 measurement 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, automobile repair, blasting, painting, lacquering, certain foundry operations, diesel e.xhausts, etc. C .I d Ezamples of THRESHOLD LIJfIT FdLUES FOR MIXTURES The following formulae apply only when the components in a mixture have similar toxicologic effects; they should not be used for mixtures with widely differing reactivities, e.g. hydrogen cyanide & sulfur dioxide. In such case the formula for Independent Effects ( l a c . ) should be used. 47 .... . . _ . ~ ... . . .- .. lA.a. General case, where air is analyzed for each component: a. Additive effeds. (Note: It 6 esacn- cial that the atmosphere be analyzed both qualitdively and quantitatively f o r each component present, in order to d z l a t e compliance OT noncompli- ance with this calculated TLT'.) c1 cz- + - + - + . e . = Ti TZ C3 "3 1 Example So. 1X.a: Air contains 5 ppm of car bontetrachloride (TLV = 10 ppm) 20 ppm of 1, 2-dichloroethane (TLV =50 ppm) and 10 ppm of 1, 2dibromoethane (TLV = 20 PPm) .4tmospheric concentra- +tion of mixture = 5 +20 10 = 35 ppm of mixture 5 20 10 25 f 2 0 4 - 2 5 = 10+50+20= 50 Threshold Limit is exceeded. Furthermore, the TLV of this mixture may be calculated by redwing the total fraction to 1.0; i.e. -TLV of mixture = 35 1.4 = 25 PPm lA.b. Special case when the source of contaminant is a liquid mixture and the 48 I ! 0 a 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 eJecta (approximate solution) 1. The percent Eomposition (by weight) of the liquid mixture is known, the TLVs of the constituents must be listed in mgjmJ. (Note: I n order to evaluate compliance .with this T L V , field sampling instrumenk, should be calibrated, in the labotaiol.y, for resporwe to this specific quantitative and qualitdire airlvapor mutuTe, and abo to fractional concentrations of this mizlwe; e.g., 1/2 the TLV; 1/10 the TLI'; 9 X the TLJ'; 10 X the TLI'; etc.) TLV of mixture = 1 fa TLV, fa +TLVb +-f, +...-fn TLV, TLV, Example No. 1: Liquid solvent contains (by weight) 50% heptane (TLV = 1600 mrg/m3) 30% methylene chloride (TLV = 720 mgjma) 20Yo perch 1oroet h y1ene (TLV = 6iO mg/m3) TLV of mixture = 1 -0.+5 A0+3 - 02 1600 720 670 49 +- 1 - 1 0.00031 -!-0.00042 0.0003 0.00103 = lo00 mg!m3 (approximately) To convert to ppm, consult TLV list: 50Vo heptanp = 200 ppm 30C0methylene chloride 5: 33 ppm 20% perchloroethylene = 20 ppm + +TLV of mixture: 200 60 20 = 280 ppm 1A.c. Independent effeckl. Air contains 0.15 mg/m3 of lead (TLV, 0.15) and 0.7 mg/m3of sulfuric acid (TLV, 1). -00..-1155 - 1; -O1e7 = 0.7 Threshold limit is not exceeded. 1B. 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% nonasbestiform talc and 2070 quartz, the TLJ- for 100% of the mixture is given by: +-TLV = 1 -0.8 0.2 = 16 mppcf 20 10 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: 50 I- + w + -1 TLV = -0.25 0.25 10 0.5 = 16 mppcf 20 The limit for 25% quartz approximates 9 mppcf. 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" designation; 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 tetrachloride, 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 a t or below the TLV ceiling. These limiting escursions are to be considered to provide a "rule-of-thumb" guidance 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 substances consult Pa. Rules & Regs., Chap. 4, Art. 432,and "Acceptable Concentrations," ANSI. 51 Excursion -Substance TLV Factor Nitro- PPm benzene 1 Carbon tetra- chloride 10 o-Dichloro- benzene 50 Acetone loo0 Boron trifluoride C 1 Butylamine C 5 2 1.5 1.25 - Max. Conc. Permitted for short time PPm - 20 75 1250 1 5 EXCURSION FACTORS For all substances not bearing C notation Excursion TLV >O-1 (ppm or mg/ma), Factor =3 TLV>1-10 U -2 TLV>10-100 TLV>100-1000 ` U = 1.5 u . = 1.25 The number of times the excursion above the TLV is permitted is governed by conformity with the Time-Weighted Average TLV. INTERPRETATION OF MEASURED PEAK CONCENTRATIONS With increasing use of rapid, directreading analytical instruments for airborne contaminants in the work area, the question of interpretation of essentially "instantaneous" peaks arises. Although no general statement can be made covering all occupational substances, the following guidelines should prove helpful, assuming peak excursions conform to time-weighted average TLV as stated above. The toxicologic importance of momentary peak concentrations depends on whether the substance is fast or slow acting. If slow acting, as for quartz, lead, or carbon monoxide, momentary peaks are of no toxicologic concern provided. of course, they are not astronomic. On the other hand, fast acting substances that rapidly produce disabling narcosis, e.g., HzS, or intolerable irritation or asphyxiation, ?;%,S02, COz, or initiate sensitization -the organic isocyanates, even "instantaneous" peaks, appreciably above the permissible excursion, should not be permitted, unless information exists to the contrary. Other more specific excursions will be developed in the future. 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 proposed limit for petiods up to 15 minulea may result in a) intolerable irritation, b) chronic, or irreversible tissue change, or c) narcosis of sufficient degree to increase accident 52 53 I proneness, impair self-rescue or materially reduce work efficiency. TLV? APPENDIX E Some Nuisoneo Particulatss~) TLV, 30 mppcf or 10mgjma Threshold Limit Values Aiundum ( 2 ~ 1 2 0 3 ) Kaolin Calcium carbonate Limestone Calcium siIicate Magnesite Cellulose (paper fiber) 3larble Portland Cement Mineral Wool Corundum (A&&) Fiber Emery Pen taerythri to1 Glass, fibrous" or dust Plaster of Paris Glycerin Mist Rouge Graphite (synthetic) Silicon Gypsum Silicon Carbide Vegetable oil mists Starch (except cast.or, Sucrose cashew nut, or Tin Oxide similar irritant Titanium Dioxide oils) Zinc Stearate *Zinc oxide dust q) When toxic impurities are not present, e.g. quartz < 1% r) <7rm in diameter APPENDIX F Some Simple Asphyxiants.) Acetylene Argon Butane Ethane Ethylene Helium Hydrogen Methane Neon Nitrous oxide Propane s) As defined on pg. 6. '1975 Addition. I For Physical Agents Adopted by ACGIH for 1975 1975 TLV PHYSICAL AGENTS COMMITTEE Herbert H. Jones, Central Missouri State University, Chairman Peter A. Breysse, University of Washington Irving H. Davis, Michigan Dept. of Health LCDR Joseph J. Drozd, USS Dr. David A. Fraser, Univ. of North Carolina Maj. George S. Kush. USAF Tom Cummins, Ontario Dept. of Health Dr. Wordie H. Parr, N O S H David H. Sliney, C`SAEHA Dr. Robert N. Thompson, FAA Thomas K. Wilkinson, USPHS Eugene G. Wood, US.Dept. of Labor Ronald D. Dobbin, X'IOSH Lt. Col. Robert T. Wangemann, U.S. Army Any comments or questions regarding these limits should be addressed to: Secretary - Treasurer P.O. Box 1937 Cincinnati, Ohio 45201 t PREFACE PHYSICAL AGENTS These threshold limit values refer to levels of physical agents 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 variations in individual susceptibility, exposure of an occasional individual at, or even below, the threshold limit may not prevent annoyance, aggravation of a preexisting condition, or physiological damage. These 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. 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 intended for use, or for modification for um, (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 adoption 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 revisions or additions, as further information becomes available. Notice of lrotent - 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 57 notice provides not only an opportunity for comment, but solicits suggestions of phys- ical agents t,o be added to the list. The suggestions should be accompanied by substantiating evidence. -As Legiddive Code The Conference recognizes that the Threshold Limit Yalues may be adopted in legislative codes and regulations. If so used, the intent of the concepts contained in t.he Preface should be maintained and proilisions should be made to keep the list current. Reprint Permission - This publication may be reprinted pravided that written permission is obtained from the Secretary- Henschel : "Development of Pe.rrnis&bEe Heat Ezposure Limits for Occupational Work." MHRAE ,Journal, Vol. 15: So. 9, September 1973, pp. 57-62.) Since measurement of deep body temperature is impractical for monitoring the workers' heat load, the measurement of environmental 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 (RrBGT) is the simplest and most suitable technique to memure the environmental factors. WBGT values are calculated by the folloming equations: Treasurer of the Conference and that this Preface be published in its entirety along with the Threshold Limit Values. +1. Outdoors with solar load: WBGT = O . S B 0.2GT -k O.1DB +2. Indoors or Outdoors with no solar load: WBGT = 0.7WB 0.3GT where : THRESHOLD LIMIT VALUES HEAT STRESS These Threshold Limit Values refer to heat stress conditions 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 acclimatized, fully clothed workers with adequate water and sait intake should be able to function effectively under the given working conditions without exceeding a deep body temperature of 38C (WHO technical report series #12, 1969 ReaZth Faders Involved in Working Under Conddiotw of Heat StresJ; F. N. Dukes-Dobos and A. 58 I I i I ! I I ! i 1 I i i I WBGT = Wet Bulb-Globe Temperature Index WB = Satural Wet-Bulb Temperature DB = Dry-Bulb Temperature GT = Globe Thermometer Tempera- ture . The determination of WBGT requires the use of a black globe thermometer, a natural (static) wet-bulb thermometer, and a drybulb thermometer. 59 1 I TABLE 1 Permissible Heat Exposure ThreshoId Limit Vdues (Values are given in "C. WBGT) -Work Rest Regimen Work Load Light Moderate Heavy Continuous work -75% Work 25% Rest, Each hour 50% Work - 50% Rest, Each hour -25% Work 75% Rest,Each hour 30.0 30.6 31.4 32.2 26.7 28.0 29.4 31.1 25.0 25.9 27.9 30.0 Higher heat exposures than shown in TabIe 1 are permissible 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 continue their work when their deep body temperature exceeds 38.0"C. APPENDIX G HEAT STRESS I. M e a s u r m a t of the Enuironmat The instruments required are a dry-bulb, a natural wet-bulb, a globe thermometer, and a stand. The measurement of the environmental factors &all be performed as follows: -A. The range of the dry and the natural wet bulb thermometer shall be 50C to 5OoCwith an accuracy of f0.5"C. The dry bulb thermometer mu- 0 shielded from the I sun and the other ra . <,litsurfaces of the I 60 L-- 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 temperature 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 1/2 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. B. One globe thermometer, consisting of a 15 cm. (6-inch) diameter hollow copper sphere, painted on the outside wlth a matte black finish or equivalent shall be used. The bulb or sensor of a thermometer (range -5C to 100C with an accuracy of f0.5"C) must be fixed in the center of the sphere. The globe thermometer shall be exposed a t least 25 minutes before it is read. C. One stand shall be used to suspend the three thermometers so that they do not restrict free air flow around the bulbs, and the wet-bulb and globe thermometer are not shaded. D. It is permissible to use any other type of temperature sensor that gives identical reading to 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, respectively. 61 The methodology outlined above is more fully explained in the following publications: 1. "Prevention of Heat Casualties in Marine Corps Recruits, 1955-1960,Nlth Comparative Incidence Rates and Climatic Heat Stresses in other Training Categories," by Captain David Minard, MC,USN, Research Report No. 4, Contract So. MR005.01OOO1.01,Naval Medical Research Institute, Bethesda, Maryland, 21 February 1961. 2. "Heat Casualties in the Savy and Marine Corps, 19S9-1962, uith -1ppendices on the Field Use of the Wet Bulb-Globe Temperature Index," by Captain David Minard, MC, USN, and R. L. O'Brien. HMC, USS. Research Report S o . 7, Contract 90. MR 005.01-0001.01, Saval Medical Research Institute, Bethesda, Maryland, 12 March 1964. 3. Minard, D.: Prevention of Heat Casual- ties in Marine Corps Recruits. Military Medicine l26(4): 261-272,1961. 11. Work Load Categories The heat produced by the body and the environmental heat together determine the total heat load. 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 work load evaluated against the applicable standard in order to protect the worker from exposure beyond the permissible limit. A. The work load category may be established by ranking each job into light, medium, and heavy categones on the basis of type ofoperation, where the work load is ranked into one of said three categories, i.e. 62 (1) light work (up to 200 Kcalihr or 800 Btu/hr): e.g., sitting or standing to control machines, performing light hand or arm work, (2) moderate work (200-330 Kcal/hr or 800-14M Btulhr) : e.g., walking about uith moderate lifting and pushing, (3) heavy work (350-500 Kcal/hr or 1400-2000 Btu/hr): e.g., pick and shovel work, the permissible heat exposure limit for that work load shall be determined from 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 by the use of the scheme shown in Table 2. Tables available in the literature listed below and in other publications as well may also be utilized. When this method is used the permissible heat exposure limit can be determined by Figure 1. 1. Per-Olaf Astrand and Kaare Rodahl: "Textbook of Work Physiology" McGrawHill Book Company, New York, San Francisco. 1970. 2. "Ergonomics Guide to Assessment of Metabolic and Cardiac Costs of Physical Work." h e r . Ind. Hyg. Assoc. J. 32: 560, 1971. 3. Energy Requirements for Physical Work. Purdue Farm Cardiac Project. Agricultural Experiment Station. Research Progress Report No.30,1961. 4. J. V. G. A. Durnin and R. Passmore: "Energy, Work and Leisure." Heinemann Educational Books, Ltd., London, 1967. 63 TABLE 2 Assessment of Work Load Average values of metabolic rate during different activities. A. Body position and movement Kcal./min. Sitting 0.3 standing 0.6 Walking 2.0-3.0 Walking up hill add 0.8 per meter (yard) rise B. Type of Work Average Range Kcal./min. Kcal./min. Hand work light heavy 0.4 0.9 0.2-1.2 Work with one arm light heavy 1.O 1.8 0.7-2.5 Work with both arms light heavy 1.5 2.5 1.0-3.5 Work with body light moderate heavy veryheavy 3.5 5.0 7.0 9.0 2.5-15.0 Light hand work: writing, hand knitting Heavy hand work: typewriting Heavy work with one arm : hammering in nails (shoemaker, upholsterer) Light work with two a m : filing metal, planing wood, raking of a garden 64 ! i i Moderate work with the body: cleaning a floor, beating a carpet Heavy work with the body: railroad track i laying, digging, barking trees I i Sample Calculation: Using a heavy hand tool ! on an assembly line i A. Walking along 2.0 Kcal./min. i B. Intermediate value between t heavy work with two arms and light work with the body 3.0 Kcal./min. 5.0 Kcal./min. C. Add for basal metabolism 1.0 Kcal./min. Total 6.0 Kcal./min. Adapted from Lehmann, G.E., A. Muller and H. Spitzer : Der Kalorienbedarf bei gewerblicher Arbeit. Arbeitsphysiol. 14: 166, 1950. 111. Wmk-Rest Regimen The permissible exposure limits specified in Table I and Figure 1 are based on t,he assumption that the WBGT value of the resting place is the Same or very close to that of the work place. If the resting place is air conditioned and its climate is kept a t or below 24C (75F.) WBGT, the allowable resting time may be reduced by 25%. The permissible exposure limits for continuous work are applicable where there is a workrest regimen of a N a y work week and an %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 resting time is ailowed. All breaks, including unscheduled 65 I pauses and administrative or operational waiting periods during work may be counted as rest time when additional rest allorvance must be given because of high environmental temperatures. It is a common experience that when the work on a job is self-paced, the workers will spontaneously limit their hourly work load to 30210%of their maximum physical performance capacity. They do this either by setting an appropriate work speed or by interspersing unscheduled breaks. Thus the daily average of the workers' metabolic rate seldom exceeds 330 kcal/hr. However, within an 8-hour work shift there may be periods where the workers' hourly average metabolic rate will be higher. IV. Water and Salt Supplementation During the hot season or when the worker is exposed to artificially 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 mi or 1/'4pint). The water shall be kept reasonably cool (10-150C or 50.0-60.00F)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 abundantly during the hot Season and particularly during hot spells. If the workers are unacclimatized, salted drinking water shall be made available in a concentration of 0.1% (le. NaCl to 1.0 liter or 1 level tablespoon of ' t to 15 quarts of water). 66 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 impedes sweat evaporation or has higher insulation value, the worker's heat tolerance is reduced, and the permissible heat exposure limits indicated in Table 1 and Figure 1 are not appiicable. For each- job category where special clothing is required, the permissible heat exposure limit shall be established by an expert. B. Acclimatization and Fitness: The recommended heat stress TLVs are valid for acclimated workers who are physically fit. i i i I L P` iI i ! ! /1 u; i i I.a0 t3 ! ! I I i KcoI / hr 400 800 I200 1600 2000 BTU/hr Rote of Work Figure 1 - Permissible Heat Exposure Threshold Limit Value 68 t I! i i IONlZlNO RADIATION See U.S.Department of Commerce National Buread of Standards, Handbook 59, "Permissible Dose from External Sources of Ionizing Radiation," September 24, 1954, and addendum of April 15, 1958. A report, Basic Radiation Protection Criteria, pub- lished by the Sational Committee on Rsdia- tion 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. 2o008. LASERS The threshold limit values 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 h e 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 TLVs for the eye in the spectral range of 4001400 nm, which should be averaged over a 7 mm limiting aperture (pupil); and except for all TLVs for wavelengths between 0.11 mm where the limiting aperture is 10 mm. No modification of the TLVs is permitted for pupil sizes less than 7 mm. The TLVs for "extended sources" apply to sources which subtend an angle greater than a (Table 5) which varies with exposure *See Sotice of Intended Change, Page 93. 69 time. This angle is not the beam divergence of the source. Cwrectwn Factor8 A and B (CAand CS) for Eye Exposure All TLYs in Tables 3 and 4 are to be used as given for wavelengths 400 nm to 700 nm. At all wavelengths greater than 1.06 pm and less than 1.4 pm the TLVs are to be increased by a factor of 5. TLV a t wavelengths between 700 nm and 1.06 pm are to be increased by a uniformly extrapolated factor as show-n in Figure 2. For certain exposure durations at wavelengths between 700800 nm, correction factor C Bis applied. Repetitively Pulsed Laser8 Since there are few experimental data for multiple pulses, caution must be used in the evaluation of such exposures. The protection standards for irradiance or radiant exposure in multiple pulse trains have the following limitations: (1) The exposure from any single pulse in the train is limited to the protection standard for a single comparable pulse. (2) The average irradiance for a group of pulses is limited to the protection standard as given in Tables 3 , 4 , or 6 of a single pulse of the same duration as the entire pulse group. (3) When the Instantaneous Pulse Repetition Frequency (PRF) of any pulses within a train exceeds one, the protection standard applicable to each pulse is reduced as shown in Figure 6 for pulse durations less than lod second. For pulses of greater duration, the following formula should be followed: 70 c (Standard single pulse in train Standard (pulse n.r) n where : n = number of pulses in train 7 = duration of a single pulse in the train Standard (n.;) = protection standard of one pulse having a duration equal to n: seconds b 700 I 900 I., 1100 I1 1300 I Wovolongth (nm) Figure 2. TLV correction factors for laser wavelengths (eye). 71 i i 11 1 i iI I I ! I iI I i I 1 iI I 72 * 0 73 ! 74 a i 3 75 I 76 77 L UI0- i 1 c0 u LeW s t 0.01[L I 10 lW loo0 N C f E R E X t I W + 4 WOUENCy. PRf Hr I Figure 6. Multiplicative correction factor for repetitivelypulsed lasershaving pulse durationsless than 1 0 - 6 second. TLV for a single pulse of the pulse train is multiplied by the above correction factor. Correction factor for PRF greater than lo00 H, is 0.06. 5+ 53 78 79 , .I E6 ..-_- ---. .____-*Im h* - - Iz 5s -83' s H 3 9 8 h u 80 31 _...- I ! ! 1 j t i f i I i i ; cE I; 8 2 0 4 Ec 8" 'cy ! c ! f I i 82 ! I a3 i ! i I J i MICROWAVES* NOISE* These Thrpshold Limit Values refer to microwave energy in the frequency range of 100 MHs to 100 GHz and represent conditions under which it is believed that nearly all workers may be repeatedly exposed without adverse effect. These values should be used as guides in the control of exposure of microwaves and should not be regarded as a fine line between safe and dangerous levels. Recommended Value8 The Threshold Limit Value for occupational microwave energy exposure where power densities are known and exposure time controlled is as follows: 1. For average power density levels up to but not exceeding 10 milliwatts per square centimeter, total exposure time shall be These threshold limit values refer to sound pressure levels and durations of exposure that represent conditions under which it is believed that nearly all workers may be repeatedly exposed without adverse effect on their ability to hear and understand normal speech. The medical profession has defined hearing impairment as an average hearing threshold level in excess of 25 decibels (AXSI-S3.6-1969) a t 500, 1O00, and 2ooo Hs,and the limits which are given have been established to prevent a hearing loss in excess of this level. The values should be. used as guides in the control of noise exposure and, due to individual susceptibility, should,not be regarded as fine linea between safe and dangerous levels. Continuous or Zntcrmi#nt limited to the %hour workday (con- The sound level shall be determined by a tinuous exposure). 2. For average power density levels from 10 milliwatts per square centimeter up to sound level meter, conforming as a minimum to the requirements of the American Xationd Standard Specification for Sound but not exceeding 25 milliwatts per square Level Meters, S1.4 (1971) Type S2A, and centimeter, total exposure time shall be limited to no more than 10 minutes for set to use the A-weighted network with slow meter response. Duration of exposure shall any 60 minute period during an &hour not exceed that shown in Table 7. workday (intermittent exposure). These values apply to total duration of 3. For average power density levels in exces exposure per working day regardless of of 25 milliwatts per square centimeter, whether this is one continuous exposure or a I exposure is not permissible. number of short-term exposures but does NOTE: For repetitively pulsed sources the not apply to impact or impulsive type of average power density may be calculated by noise. multiplying the peak power density by the When the daily noise exposure is composed duty cycle. The duty cycle is equal to the of two or more periods of noise exposure of pulse duration in seconds times the pulse different levels, their combined effect should repetition rate in hertz. be considered, rather than the individual 'SPP Xotice of Intent to Study, Page 97. 84 *See Notice of Intended Changes, Page 95. 85 - _-. effect of each. If the sum of the follo-ing fractions : -c+, % + . . . -Cn TI T n exceeds unity, then, the mixed exposure should be considered to exceed the threshold limit value, C1 indicates the total duration of exposure at a specific noise level, and TI indicates the total duration of exposure permitted a t that level. .All on-the-job noise exposures of 80 dB-4 or greater shall be used in the above calculations. Impukive or Impact Soise It is recommended that exposure to impulsive or impact noise should not exceed 140 decibles peak sound pressure level. Impulsive or impact noise is considered to be those variations in noise levels that involve maxima at intervals of greater than one per second. Where the intervals are less .than one second, it should be considered contin uous Table 7 Threshold Limit Values Duration per day Hours Sound Level dBA" 16 80 8 85 4 90 2 95 1 100 1/2 105 1/4 110 1/8 115' +No exposure to continuous or intermittent in excess of 115 dBA 86 a) Sound level in decibels as measured on a sound level meter, conforming as a minimum to the requirements of the American National Standard Specification for Sound Level Meters, S1.4 (1971) Type SZA, and set to use the A-weighted network with slow meter response. 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 testing is necessary when workers are exposed to noise at or above the TLV levels. ULTRAVIOLET RADIATIOhJ* These threshold limit values refer to ultraviolet radiation in the spectral region between 200 and 400 nm and represent conditions under which it is believed that nearly all 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 levels should not be used for determining exposure of photosensitive individuals to ultraviolet radiation. These values should be used as guides in the control of exposure to continuous source8 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 'See Laser TLVs. 87 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 mm) total irradiance incident upon the unprotected skin or eye should not exceed 1 mw/cmz for periods greater than 10' seconds (approximately 16 minutes) and for exposure times less than IOJ seconds should not exceed one J/cmz. 2. For the actinic ultraviolet spectral region (200 -315 nm), radiant exposure inci- dent upon the unprotected skin or eye should not exceed the values given in Table 8 within an &hour period. 3. To determine the effectiveirradiance of a broadband source weighted against the peak of the spectral effectiveness curve (2iO nm), the followingweighting formula should be used: CE,lj = Ea s i ~x where : E.,/ = effective irradiance relative to a monochromatic source at 270 nm E l = spectral irradiance in W/cm*/nm SI = relative spectral effectiveness (unitlesa) A I = band width in nanometers 88 i I 1 i I ii I i f I I i i i t I 4. Permissible exposure time in seconds for exposure to actinic ultraviolet radiation incident upon the unprotected skin or eye may be computed by dividing 0.003Jicm2 by E<,, in W/cm2. The exposure time may also be determined using Table 9 which provides exposure times corresponding to effective irradances in FW/crn2. TABLE 8 Relative Spectral Effectiveness by Wavelength Wavelength bm> TLV (mJ/cm2) Relative Spectral Effectiveness SI 200 100 0.03 210 40 0.075 220 25 0.12 230 16 0.19 240 10 0.30 250 7.0 0.43 254 6.0 0.5 260 4.6 0.65 270 3.0 1.o 280 3.4 0.88 290 4.7 0.64 300 10 0.30 305 50 0.06 310 200 0.015 315 lo00 0.003 89 , ..... .*I. TABLE 9 Permissible Ultraviolet Exposures Duration of Exposure Effective Irradiance, Per Day GIIbW/cm*? 8 hrs.. . . . . . . . . . . . . . . . . . 0.1 4 hrs.. . . . . . . . . . . . . . . . . . 0.2 2 hrs.. . . . . . . . . . . . . . . . . . 0.4 l h r.................... 0.8 1/2 hr.. . . . . . . . . . . . . . . . . 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 ,. 1 I I ! All the preceding TLV's for ultraviolet energy apply to sources which subtend an angle less than 80". Sources which subtend a greater angle need to be measured only over an angle of 80'. I1I 1 I t 0 001 200 1I I II I 220 240 260 280 300 320 WAVE LENGTH (NANOMETERSI 1 J 340 Figure 7. Threshold Limit Values for Ultraviolet Radiation Conditioned (tanned) individuals can tolerate skin exposure in excess of the TLV without erythemal effects. However, such conditioning may not protect persons against skin cancer. c NOTICE OF INTENDED CHANGES (for 1975) 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 a t least one year. If, after one year no evidence comes to light that questions the appropriateness of the values herein~.- the values will be reconsidered for the "Adopted" list. i i i ! i i I I ! / .... .I I E 2II C W 3 c1 92 93