Document em6YxG4MYLD77rRgjVv4Dg0dG
f Threshold Limit Values For 1965
f c
Adopted at the 27th Annual Meeting of the American Conference of Governmental Indus trial Hygienists, Houston, Texas, May 2-4
i 1965
EC- 2009
Copyright 1965, by American Conference of Governmental Industrial Hygienists,
The American Conference of Governmental Industrial Hygienists will welcome requests for permission to republish or reprint these Thres hold Limit Values.Requests for such permission should be directed to the Secretary-Treasurer, 1014 Broadway, Cincinnati, Ohio 45202.
The 2nd edition of the Documentation of Threshold Limit Values, rewritten and greatly^ enlarged to include the approximately 400 sub- stances in the list will be available shortly and may be purchased from the Secretary-Treasurer. The Documentation should be consulted when using the Threshold Limit Values herein.
Single Copies -- 30 cents
THRESHOLD LIMIT VALUES FOR 1965
Adopted at the 27th Annual Meeting of the American Conference of Governmental Industrial Hygienists, Houston, Texas May 2-4, 1965.
The Threshold Limit Values refer to air-bome concentrations of substances and represent con ditions under which it is believed that nearly all workers may be repeatedly exposed, day after 'ay, without adverse effect. Because of wide
r ariation in individual susceptibility, exposure of an occasional individual at or even below the threshold limit may not prevent discomfort, ag gravation of a pre-existing condition, or occupa tional illness.
Threshold limits should be used as guides in the control of health hazards and should not be regarded as fine lines between safe and dan gerous concentrations. Exceptions are the sub stances given in Appendix A and certain of the substances given a "C" listing. The values not given a "C" listing refer to time-weighted aver age concentrations for a normal workday. The amount by which these concentrations may be exceeded for short periods without injury to health depends upon a number of factors 3Uch as the nature of the contaminant, whether very high concentrations even for short periods produce acute poisoning, whether the effects are cumula tive, the frequency with which high concentra tions occur, and the duration of such periods. All must be taken into consideration in arriving at a decision as to whether a hazardous situa tion exists. Enlightened industrial hygiene prac tice inclines toward controlling exposures below the limit rather than maintenance at the limit.
Threshold limits are based on the best avail able information from industrial experience, from experimental human and animal studies, and when possible, from a combination of the three. The basis on which the values are established may differ from substance to substance; protec
dom from irritation, narcosis, nuisance or other forms of stress may dominate the basis fOT others. The Committee holds to the opinion that
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EC- 2010
limits based on physical irritation should be considered no less binding than those based on physical impairment; growing bodies of evidence indicate that physical irritation may promote and accelerate physical impairment.
Documentation of Threshold Limit Values. A separate companion piece to the TLVs will be issued by ACGIH under this title. This publicagives the pertinent scientific information and dag ta with reference to literature sources, that werf used to base each limit. Each documentation al so contains a statement defining the type of response against which the limit is safeguarding the worker. For a better understanding of the TLVs it is essential that the Documentation be consulted when the TLVs are being used.
Ceiling vs Time-Weighted Average Limits. Although the time-weighted average concentra- f
tion provides the most satisfactory, practical V
way of monitoring air-bome agents for compli ance with the limits, there are certain substan ces for which it is inappropriate. In the latter group are substances which are predominantly fast acting and whose threshold limit is more appropiately based on this particular response. Substances with this type of response are best controlled by a ceiling "C" limit that should not be exceeded. It is implicit in these defini tions 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 "C" limit, is not appropriate to the timeweighted limit; here, a sufficient number of sam ples 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 peg^ ged to the magnitude of the threshold limit by an ~ appropriate factor shown in Appendix C. It should be noted that the same factors are used
by the Committee in making a judgement whether to include or exclude a substance for a "C" listing.
"Skin Notation, Listed substances followed ^ by the designation "Skin" refer to the potential
contribution to the over-all exposure by the cu taneous route including mucous membranes and eye, either by air-bome. or more particularly, by direct contact with the substance. Vehicles can alter skin absorption. This attention-calling de^ignation is intended to suggest appropriate
r tasures for the prevention of cutaneous absorpon so that the threshold limit is not invalidat ed.
Mixtures. Special consideration should be given also to the application of these values in assessing the health hazards which may be as sociated with exposure to mixtures of two or more substances. A brief discussion of basic considerations involved in developing threshold " limit values for mixtures, and methods for their development, amplified by specific examples are given in Appendix B.
"Inert** or Nuisance Particulates. A number of dusts or particulates that occur in the working environment ordinarily produce no specific ef fects upon prolonged inhalation. Some insoluble substances are classed as inert (e.g. iron and steel dusts, cement, bentonite, silicon carbide, titanium dioxide,cellulose); others may be solu ble (starch, soluble oils, calcium carbonate) but are of such a low order of activity that in con centrations ordinarily encountered do not cause physiologic impairment; still others may be ra pidly eliminated or destroyed by the body (veg etable oils, glycerine, sucrose). In the case of the insoluble substances, there may be some ac cumulation in the respiratory passages. In the case of the soluble substances, this accumula tion will ordinarily be temporary but may inter fere to some extent with respiratory processes. Hence, it is desirable to control the concentra tions of such particulates in the air breathed by / y individual, in keeping with good industrial \ giene practic.
A threshold limit of 15mg/m , or 50 mppcf, whichever is less, is recommended for substan-
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EC- 2011
ces in these categories and for which no speci fic threshold limits have been assigned. This limit, for a normal work day, does not apply to brief exposures at higher concentrations. Neither does it apply to those substances which may
'fcause physiologic impairment at lower concen
trations but for which a threshold limit has no yet been adopted. Some ``inert" particulates are given in Appendix D.
Simple Asphyxiants-"Inert" Gases or Vapo>rrss^^ A number of gases and vapors, when present/ high concentrations in air, act primarily as sian pie asphyxiants without other significant phy siologic effects. A TLV may not be recommend ed for each simple asphyxiant because the limit ing factor is the available oxygen. The minimal oxygen content should be 18 percent by volume under normal atmospheric pressure (equivalent to a partial pressure, pOz, of 135 mm Hg). Atmos pheres deficient in 0a do not provide adequate warning and most simple asphyxiants are odor- ^ less. Several simple asphyxiants are listed inf Appendix E. Some asphyxiants present an ex-\ plosion hazard. Account should be taken of this factor in limiting the concentration of the asphyiant.
These limits are intended for use in the field of industrial hygiene and should be interpreted and applied only by persons trained in this field. They are not intended for use, or for modifica tion for use, (1) as a relative index of toxicity, by making a ratio of two limits, (2) in the evalu ation or control of community air pollution or air pollution nuisances, (3) in estimating the toxic potential of continous uninterrupted exposures, (4) as proof or disproof of an existing disease of physical condition, or (5) for adoption by coun tries whose working conditions differ from those in the U.S.
adversely to increase the toxic response of a substance. Although most threshold limits have built-in safety factors to guard against adverse effects of moderate deviations from normal en vironments, the safety factors of most substances ate not of such a magnitude aa to take care )' of gross deviations. For example, continous work at temperatures above 90"F of over-time, extending the work-week more than 50%, might be considered gross deviations. In such instan
rces judgement must be exercised in the proper idjustments of the threshold limit values.
These values are reviewed annually by the Committee on Threshold Limits for revision or additions, as further information becomes avail able.
"Notice of Intent** At the beginning of each year, proposed actions of the Committee for the forthcoming year are issued in the form of a
r "Notice of Intent. '' This Notice provides not only an opportunity for comment, but solicits suggestions of substances to be added to the list. The suggestions should be accompanied by substantiating evidence.
Legislative Action. The Conference does not consider the Threshold Limit Values appropriate matter for adoption in legislative codes and re gulations, and recommends against such use. If however, the list is so used, it should be based on the current TLV list and pertinent documenta tion.
Reprint Permission. This publication may be reprinted provided that written permission is ob tained from the Secretary-Treasurer of the Con ference and that it be published in its entirety.
Physical Factors. It is recognized that such physical factors as heat, ultraviolet and ionize ing radiation, humidity, abnormal pressure aa the like may place added stress on the body SV that the effects from exposure at a threshold limit may be altered. Most of these stresses act
(
45
eC~ *012
RECOMMENDED VALUES (In Alphabetical Order)
Subitanc*
ppm*
M9/M1**
Acetaldehyde.......
200
Acetic acid...........
10
Acetic anhydride. Acetone..................
5
.1, 000
Acetonitrile......... Acetylene tetrabromide.................
40 1
Acrolein...........................................
0.1
Acrylonitrile - Skin....................... 20
Aldrin (1, 2, 3, 4, 10, 10-
hexachloro-l, 4, 4a, 5, 8, 8a
hexahydro-1, 4, 5, 8-di-
methano-napthalene) - Skin....
-
Allyl alcohol - Skin....................... Allyl chloride..................................
2 1
Allyl glycidyl ether (AGE).......... 10
Allyl propyl disulfide...................
2
Ammonia........................................... 50
Ammonium sulfamate (Ammate).. -
n-Amyl acetate................................ 100 Amyl alcohol (isoamyl alcohol).. 100
Aniline - Skin.................................. Antimony 8. compounds (as Sb)..
5 -
ANTU (alpha naphthyl
thiourea)....................................... -
Arsenic 8> Compounds (as As)..
Arsine................................................ Barium (soluble compounds)......
0.05 -
Benzene (benzol) * Skin.............. 25
Benzidine-Skin..............................
-
Benzyl chloride..............................
1
Beryllium......................................... -
Boron oxide.................................... Boron trifluonde............................
1
Bromine.............................................
0.1
Butadiene (1, 3-butadiene)........1,000
f360 25 20 2,400
70 14 x.
45 '
0,25 5 3 45 12
35 L
15 V
525 360
19 0.5
0.3 0.5 0.2 0.5 80 A1 5 0.002 15 3 0.7 2,200
* Parts of vapor or gas per million parts of air by volunr* at 25"C and 760 mm. Hg pressure
"Approximate milligrams of particulate per cubic meter of air,
A Numbers. See Appendix A
Substanc*
ppm*
Me/M1**
2-Butanone (methyl ethyl
ketone)......................................... 200
590
2-Butoxy ethanol (Butyl Cellosolve) - Skin.....................
Cj- Butyl acetate (n-butyl acetate)..
50 -
240 -
Butyl alcohol................................... 100 tert. Butyl alcohol........................ 100
300 300
C Butylamine-Skin............................
5
15
s--C tert. Butyl chromate (as CrOs)
f - Skin............................................ n-Butyl glycidyl ether (BGE)-Butyl mercaptan.............................. p - tert. Butyltoluene..................... Cadmium oxide fume..................... Calcium arsenate............................ Calcium oxide................................. Camphor............................................
50 10 10 -
-
0.1 270
35 60
0.1 1 5
2
Carbon dioxide................................ 5,000
9,000
f Carbon disulfide - Skin................ 20 60
v
|| Carbon monoxide...........................
-
-
Carbon tetrachloride - Skin........ 10
65
Chlordane (1, 2, 4, 5, 6, 7, 8,
8-octachloro-3a, 4, 7, 7a
tetrahydro-4, 7-methanoindane) - Skin................................
-
0.5
Chlorinated camphene, (toxaphene)-Skin.....................
Chlorinated diphenyl oxide........ + Chlorine...........................................
Chlorine dioxide............................ C Chlorine trifluoride....................... C Chloroacetaldehyde.......................
-
0.1 0.1 1
0.5 0.5 0.3 0.4 3
Chlorobenzene (monochlorobenzene)............... 75
Chlorobromomethane...................... 200 Chlorodiphenyl (42% chlorine) - Skin-
350
1,050 1
Chlorodiphenyl (54% chlorine) - Skin-
0.5
,
C Chloroform (trichlotomethane).... 50
240
1-Chloro-l-nitropropane............. 20
100
( Chloropicrin.
0.1 0.7
+ 1965 Addition or dolotion of 'C'-ooo Tontotfv* Value*
t!964 Rovioion -soe Tentative Valu**
TT1965 Revision ** Tentative Value*
EC- 2013
Substance
ppm*
Mg/M1**
Substoneo
ppm*
Mg/M1**
Chloroprene (2-chloro-l,
3-butadiene) - Skin.................
25
Chromic acid and chromates
(as CrOa).................................. Cobalt............................................. Copper Fume................................
--
Dusts and Mists.......................
Crag (R) herbicide []sodium 2-(2,4-
dichlorophenoxy) ethanol
hydrogen sulfate^ ................. Cresol (all isomers) Skin........ Cyanide (as CN) - Skin...............
5
ft Cyclohexane..................................
Cyclohexanol................................ Cyclohexanone.............................. ft Cyclohexene..................................
50 50
2,4-D (2,4-dlchlorophenoxy
-acetic acid).............................. DDTQ2,2-bis (p-chlorophenyl) -
--
1,1, l-trichloroethanej- Skin
-
DDVP (0, O-Dimethyl-2, 2-dichloro-
vinyl phosphate) - Skin...........
-
Decaborane - Skin........................ Demeton (systox) (R) - Skin....... Diacetone alcohol (4-hydroxy-
0.05 1.0
4 - methyl-2-pentanone)............ Diborane.......................................... + 1,2-Dibromoethane (ethylene
50 0.1
dibromide) - Skin...................... C o-Dichlorobenzene........................
p-Dichlorobenzene........................
50 75
Dichlorodifluorome thane.............. .1,000 1,1-Dichloroethane...................... . 100 1,2-Dichloroethane
(ethylene dichloride)................ 50
1, 2-Dichloroethylene.................. 200 C Dichloroethyl ether-Skin.............. 15
Dichloromonofluoromethane........ 1,000 C 1,1-Dichloro-l-nitroethane.......... 10
Dichlorotetrafluoroethane............ 1,000
90
0.1 f
0.5 \ 0.1 1.0
/* 15 { 22 '
5 200 200
-
10
i
1 0.3 -
r-
r
Xu
240 0.1
-
300 450 4,950 400
200 790
90 4,200
60 7,000
/
Dieldrin (1,2,3,4,10,10-hexachloro
-6,7-epoxy-1,4,4a, 5,6,7,8,8a-
^ octahydro-1,4, 5,8-dimethano-
^
naphthalene)- Skin...................
-
' Diethylamine................................... 25
Difluorodibromomethane............... 100
C Diglycidyl ether (DGE).................
0.5
f
f
Diisobutyl ketone..........................
Dimethyl acetamide - Skin.......... Dimethylaniline (N-dimethyl-
50 10
aniline) - Skin............................ f Dirnethylformamide - Skin.............
5 --
1,1-Dimethylhydrazine Skin .... Dimethylsulfate - Skin.................
0.5 1
Dinitrobenzene (all isomers) - Skin...................
--
s'*"
Dinitro-o-cresol * Skin................. Dinitrotoluene - Skin......................
Dioxane
_ _
' (diethylene dioxide) Skin...... 100
Dipropylene glycol methyl
ether - Skin................................... 100 Endrin (1,2,3.4.10.10-hexa-
ch loro-6,7-epoxy*l, 4.4a, 5,6.7.8
8a-octahydro 1,4-endo-S, 8-dimethanonaphthalene) - Skin --
Epichlorhyrin-Skin..........................
5
EPN (O-ethyl O-p-nitropheny! thionobenzenephosphonate)-Skin
--
Ethanolamine..................................
3
Ethyl acetate................................... 400
Ethyl acrylate - Skin.................... 25
Ethyl alcohol (ethanol)................. 1, 000
ft Ethylamine.......................................
--
|f C Ethylbenzene..................................
--
Ethyl bromide................................... 200
Ethyl chloride................................ 1, 000
Ethyl ether........................................ Ethyl formate.................................. L+C Ethyl mercaptan..............................
400 100
-
0.25 75 860
2.8 290 35
25 -- 1 5
1 0.2 1.5
360
600
0.1 19
0.5 6 1,400 100 1,900
-- --
890 2,600 1,200
300
--
+1965 Addition or delation of *C#-**o Tontativa Volvo* f 1964 Revision - Ton to five Values ft 1965 Revision -see Tentative Values
EC- 2014
5ubstqne
ppm*
Mp/M***
Ethyl silicate.................................. Ethylene chlorohydrin * Skin...... Ethvienediamine........................... C Ethylene glycol dinitrate - Skin
100 5 10 0.2
850 16 25 i.2
r
f
I
Ethylene oxide................................ 50
2-Ethoxyethanol -Skin.................. 2-Ethoxyethylacetate
(Cellosolve acetate) - Skin ....
200 100
Ferbam (ferric dimethyl
dithiocarbamate)....................... -
Ferrovanadium dust..................... -
Fluoride (as F) ............................ -
Fluorine...........................................
0.1
Fluorotrichloromethane................. 1,000
C Formaldehyde........................... _..
5
Furfural - Skin................................
5
Futfuryl alcohol.............................. 50
Gasoline............................................ 500
Glycidol (2, 3-Epoxy*1-
propanol)..... ................................. hafnium.............................................
50 -
Heptachlor (1, 4, 5, 6, 7, 8,
8a-heptachloro-3a, 4, 7,
7a-tetrahydro-4, 7methanoindane)-$kin..............
-
Heptane (n-heptane)..................... 500
Hexane (n - hexane)........................ 500
Hexanone (methyl butyl ketone) 100
sec - Hexyl acetate........................ Hexone (methyl isobutyl ketone) Hydrazine - Skin............................
50 100
1
Hydrogen bromide.........................
3
C Hydrogen chloride..........................
5
Hydrogen cyanide-Skin............... 10
Hydrogen fluoride.......................... Hydrogen peroxide, 90%...............
3 1
Hydrogen selenide..........................
0.05
t Hydrogen sulfide............................
-
Hydroquinone................................... "
C Iodine ................................................
0.1
90 740
f540 15 1
2.5 0.2
5,600
6
20
200 2,000
150
(f
v
0.5
0.5 2,000 1,800
410
295
410
1.3 10 7 11
2 1.4 0.2 -
(2
1
$ub*tonce
ppm*
Mp/M1**
t f Iron oxide fume..............................
-
-
Isophorone ....................................... Isopropylamine.................................
25 5
140 12
'
Isopropyl glycidyl ether (IGE).... 50
240
Ketene................................................ Lead.................................................. Lead arsenate.................................
0.5 --
0.9 0.2 0.15
Lindane (hexachlorcyclohexane,
gamma isomer) - Skin..............
-
0.5
Lithium hydride...............................
0.02
Magnesium oxide fume................. --
15
Malathion (0,0-dimethyl
dithiophosphate of diethyl
mercaptosuccinate) - Skin...... -
15
C Manganese....................................... Mercury - Skin.................................
-
5 0.1
Mercury (organic compounds)
Skin................................................ Mesityl oxide...................................
25
0.01 100
t Methoxychlor (2, 2-di-p-
methoxy-phenyl-1, 1, 1-
trichloroethane).......................... -
15
Methyl acetate................................ 200
610
Methyl acetylene (propine)........ 1,000
1,650
Methyl acrylate - Skin................. 10 Methylal (dimethoxymethane).......1,000
35 3,100
Methyl alcohol (methanol).......... 200
260
C Methyl bromide - Skin................... 20
80
Methyl cellosolve (2-methoxy-
ethanol) - Skin............................. 25
80
Methyl cellosolve acetate
(ethylene glycol monomethyl
ether acetate) - Skin................. 25 C Methyl chloride.............................. . 100
120 210
Methyl chloroform (1, 1, 1 - tri-
ch lor oethane).............................. . 350
1,900
Methylcyclohexane....................... . 500
2,000
Methylcyctahexanol....................... . 100
470
o-Methylcyclohexanone * Skin... . 100
460
( Methyl formate................................ . 100
250
+1965 Addition or deletion of `C'-i Tntotiv* Valuai
10 11
EC- 2015
Substance
ppm*
Mg/M1**
Methyl isobutyl carblnol (methyl amyl alcohol) - Skin .
Methyl mercaptan........................... Methyl methacrylate.................... .
C or Methyl styrene........................... . C Methylene bis phenyl
isocyanate (MDI)...................... Methylene chloride
(dichloromethane).................... . Molybdenum ( soluble
compounds) ............................... (insoluble compounds)........... Monomethyl aniline - Skin......... Naphtha (coal tar)......................... . Naphtha (petroleum).................... . Naphthalene.................................... p - Naphthylamine......................... Nickel carbonyl............................. Nicotine Skin............................... . Nitric acid...................................... p-Nitroaniline - Skin.................. Nitrobenzene - Skin....................... Nitroe thane....................................... . C Nitrogen dioxide........................... C Nitroglycerin + EGDN - Skin.., Nitromethane.................................. . 1-Nitropropane.............................. 2-Nitropropane.............................. N - Nitrosodimethylamine (Dimethylnitrosamine) Skin .... Nitrotoluene * Skin....................... Octane................................................ Oil mist (mineral)......................... Osmium tetroxide............................ Ozone ............................................... Parathion (0, O-diethyl 0-pnitrophenyl thiophosphate) - Skin............................................. Pentaborane..................................... Pentachloronaphthalene - Skin ..
25 100 -
100 410 f 100 480 |
0.02
0.2
500 1,750 * 5C
- 15 29
200 800
500 2,000
10 50 - A2
0.001
0.007
- 0.5 - -f
1 6V
15 100 310
59 0.2 2
100 250
25 90
25 90
A3 5
500 0.1
_
30 2,350
5 0.002 0.2
0.005 -
0.1 0.01 0.5 r"`
1
Substance
ppm*
Me/M1**
Pentachlorophenol - Skin...........
--
Pentane......................................... ..1,000
(r
Pentanone (methyl propyl ketone) ....................................... ..
Perchloroethylene (tetrachloroethylene)........................ ..
200 100
Perchloromethyl mercaptan......
0.1
Perchloryl fluoride......................
3
c
Phenol - Skin................................ Phenyl glycidyl ether (PGE)....... Phenylhydrazine - Skin................
5 50
5
Phosdrin (Mevinphos) (R)
(2 - carbomethoxy *1 -
methyl vinyl dimethyl
phosphate) - Skin.....................
-
t Phosgene (carbonyl chloride).. Phosphine........................................
0.3
r
Phosphoric acid............................. Phosphorus (yellow).................... Phosphorus pentachloride........... Phosphorus pentasulfide...........
-
Phosphorus bichloride................
0.5
Picric acid - Skin.........................
-
Platinum (Soluble Salts).............
*--
Polytetrafluoro - ethylene
decomposition products........
-
|3 Propiolactone................................
-
n-Propyl acetate.......................... 200
Propyl alcohol (isopropyl
alcohol)........................................ . 400
Propyl ether (isopropyl ether)..... 500
n-Propyl nitrate........................... 25
Propylene dichloride (1, 2-
dichloropropane)...................... . 75
tt Propylene imine - Skin................
-
Propylene oxide............................. . 100
Pyrethrum........................................
-
Pyridine..........................................
5
Quinone............................................
0.1
Rotenone (commercial)................
-
0.5 2,950
700
670 0.8
13.5 19 310 22
0.1 " 0.4 1 0.1 1 1 3 0.1 0.002
A4 A5 840
980 2,100
110
350 -
240 5
15 0.4 5
+ 1965 Addition or deletion of 'C'-eee Tentotive Value* tl964 Roviion-e# Tentative Value* ffl965 R*vi*ion-*ee Tentative Value*
12 13
EC- 2016
Substgnce
ppm*
M9/M1*
-f- Selenium compounds (as Se)..... -
Sodium fluoroacetate (1080)
Skin.............................................. Sodium hydroxide............................
-
0.05
Stibme...............................................
0.1
Stoddard solvent............................ 500
Strychnine......................................... C Styrene monomer
-
0.15
(phenylethylene)........................ Sulfur dioxide................................... Sulfur hexafluoride........................ Sulfuric acid.....................................
100 5
1,000 -
13 c000 X
1
Sulfur monochloride........................
1
6
Sulfur pentafluoride........................ Sulfuryl fluoride.............................. 2, 4, ST (2, 4, 5
0.025 5
0.25 20
trichlorophenoxyacetic acid).. Tantalum........................................... TEDP (tetraethyl
dithionopyrophosphate)-Skin.. Teflon (R) decomposition
products....................................... TEPP (tetraethyl pyro
-
-
-
10
5
(0.2
A4
phosphate) Skim..................... Tellurium............... .........................
--
0.05
0.1
1, l, 2, 2-Tetrachloroethane - Skin.............................................
5
35
1, 1, 2, 2-Tetrachloro-
1, 2-difluoroethane..................... 500 Tetraethyl lead
4,170
(as Pb) - Skin..............................
-
Tetrahydrofuran.............................. 200
0.075 590
Tetranitromethane.......................... Tetryl (2, 4, 6-trinitrophenyl-
1
8
methylnitramine) - Skin........... Thallium (soluble compounds)
1.5
- Skim............................................ Thiram (tetramethy! thiuram
0.1
disulfide).................................
5
i \
Suboance
ppm*
Mp/M1**
Tin (inorganic empds)..................
-
(organic empds).........................
-
S' f
Titanium dioxide........................... Toluene (toluol) ........................... . o-Toluidine - Skin....................... C Toluene-2 4-diisocyanate.........
-
200 5 0.02
Trichloroethylene......................... . 100
Trichloronaphthalene-Skin.......
-
1, 2, 3-Trichloropropane......... 50 1 f 1, 1, 2-Trichloro 1, 2, 2-
J*
trifluoroethane........................... .1,000
| Triethylamine........... ...................... . 25
Trifluoromonobromornethane....... .1,000
Trinitrotoluene-Skin.....................
-
Triorthocresyl phosphate............
-
Triphenyl phosphate.....................
-
Turpentine...................................... . 100
Uranium (soluble compounds)...
-
(insoluble compounds)............
-
f
C Vanadtum (V z0 s dust).................
-
(VaO s fume)................................
-
C Vinyl chloride (chloroethylene)... 500
Vinyl toluene ................................ 100
Warfarin (3 -Qx acetonylbenzyfj-4*
hydroxycoumarin)........................ -
If Xylene (xylol)................................
-
Xylidme - Skin.................................
5
j Yttrium.............................................. -
Zinc oxide fume.............................
-
Zirconium compounds (as Zr).... -
2 0.1 15 750 22 0.14 520 5 300
7,600 100
6,100 1.5 0.1 3
560 0.05 0. 25 0.5 0.1
1,300 480
0.1 25
-
5 5
Radioactivity for permissible concentrations of radio-isotopes m air. see U. S Department of Commerce, National Bureau of Standards, Handbook 69. "Maximum Permissible Body Burdens and Maximum Permissible Concentrations of Radi* onuciides m Air and in Water for Occupational exposure," June S. 1959. Also, see U, S Department of Commerce National Bureau of Standards. Handbook 59. "Permissible Dose from External Sources of lomttng Radiation." September 24. 1954, and addendum of April 15. 1958.
Parts of vapor or gas per million parts of air by volume at 25'C and 7BO mm. Hg pressure.
" Approximate milligrams of particulate per cubic meter of air.
A Numbers. See Appendix A
14 15
EC- 2017
RESPIRABLE DUSTS EVALUATED BY COUNT
SuOttinci
SILICA Crystalline Quartz, Threshold Limit calculated
m. p.p.c.f.
r250
from the formula .................................. toSiOaf 5
Cristobalite > "
"
Amorphous, including natural
diatomaceous earth ..................................... 20 SILICATES (less than 1% crystalline silica)
r
Asbestos .........................................................
5
Mica .................................. ............... --..... 20
Soapstone ........................... ...............--....... 20
Talc .................................................................. 20
Portland Cement ...... ------------------------- 50
Graphite ..........................-............................. 15
"Inert" or Nuisance Particulates
50 (or 15 mg/m 3
whichever is the
smaller)
Conversion factors mppcf * 35.3 = million particles per cubic meter
= particles per c.c.
(
* Millions of particles per cubic foot of air, based on imptnger .
samples counted by light-field technics.
*
*The percentage of crystalline silica in the formula is thti
amount determined from air-borne samples, except in those ' ,
instances m which other methods have been shown to be
applicable.
16
TENTATIVE VALUES
The values below will remain in the Tentative List
for at least two years to permit presentation of further
scientific evidence to indicate their appropriateness
r for transfer to the Recommended List.
Substonee
ppm*
Mg/M3**
-H-2-Aminopyridine.............................. ++sec*Amyl acetate............................
Amsidine (o, p-isomers) - Skin .. Azinphos-methyl (Guthion)-Skin Benzoyl peroxide............................ -H-Bromoform - Skin............................ Hi-Butyl acetate.............................. ++sec-Butyl acetate......................... -H-tert-Butyl acetate......................... -H-Cadmium (metal dust and
soluble salts).............................. Carbaryl (Sevin) (R)..................... -H-Carbon black.................................. +Carbon monoxide.......................... -H-o-Ch | or benzy 1 i dene
0.5 125
*
-
-
5 150 ZOO 200
50
2 650
0.5 0.2 5 50 710 950 950
0.2 5 3.5 55
malononitrile (OCBM).............. +C Chlorine....................................... -H-Coal tar pitch volatiles (ben
.05 1
0.4 3
zene soluble fraction) (anth
racene, BaP, phenanthrene,
acridine chrysene, pyrene) ... Cotton dust (raw)...........................
-
-
0.2 1
++Crotonaldehyde.............................. 2
6
++Cumene - Skin.......... ...................... 50
245
+Cyclohexane.................................... 300 +Cyclohexene,.................................... 300
1050 1015
Cyclopentadiene............................ 75
200
++Oiazomethana..................................
0.2
0.4
+C 1, 2-Dibromo-ethane
(ethylene dibromide) - Skin..,. 25
190
++Dibutylphosphate............................ -H-Dibutylphthalate............................
2
-
10 10
1, 3 -Dichloro -5, 5-dimethyl
hydantoin..................................... -
0.2
C Diethylamino ethanol - Skin .....
10
50
* Parts of vapor or gas per million parts of ar by volume
at 25BC and 760 mm. Hg pressure
` Approximate milligrams of particulate per cubic meter of air.
1965 Revision 1965 Additions
17
EC- 2018
Substance
ppm*
Mg/M3**
Substanee
ppm*
Mg/M3**
Dimethyl 1, 2-dibromo*2, 2-
dichloroethy! phosphate.
(Dibrom) (R)................................
-
Dimethylamine................................ 10
Dimethylformamide - Skin............ 10
Di sec. octyl phlhalate (Di 2-
ethylhexyl-phthalate)............... -
+Ethyl amine.................................... 10
++Ethyl sec amyl ketone
(5-Methyl-3-heptanone)............. 25
+Ethyl benzene ............................... 100
H-Ethyl butyl ketone
(3-Heptanone).............................. 50
+Ethylene imine Skin................... +C Ethylmercaptan ..........................
0.5 10
++N-Ethylmorpholine - Skin............. 20
Fibrous glass...................................
-
H-Formic acid.....................................
5
Hexachloroethane * Skin...............
1
++sec-Hexyl acetate.......................... 50
Hydrogen sulfide............................ 10
Iron oxide fume..............................
-
++lsoamyl acetate.............................. 100
++lsobutyl acetate.............................. 150
++ Isopropyl acetate.......................... 250
L. P. G, (Liquid petroleum gas) 1000
Maleic anhydride............................
-
Methyl acetylene-propadiene
mixture, (MAPF)........................ 1000
Methylamine..................................... 10
~Methyl n-amyl ketone
(2-Heptanone)........................... . 100
-H-Methyl iodide - Skin......................
5
++Methyl isocyanate - Skin............
0. 02
Methyl mercaptan............................ 10
Methyl methacrylate
100
C Methylene bis phenyl isocyanate C Monomethyl hydrazine - Skin...
0.02 0.2
Morpholine - Skin............................ 20
Naphthalene..................................... 10
3
18 f
30 '
5 18
f
130 f 435
230 1
25 94
5
9 10 300
15 10 525 700
950 1800
8
f
1800 12
465
28
0.05 20
410 0.2 0.35
70
50 j it V
Nickel, metal and soluble
f ,
compounds .................................. Nitric acid...................................... p-Nitrochlorobenzene * Skin.......
-
2 -
1 5 1
Nitrogen trifluoride....................... 10
29
++Oxalic acid......................................
--
1
Oxygen difluoride.........................
p-Phenylene diamine Skin....... ^^t+Phenyl ether (vapor)....................
f FPhenyl ether-Biphenyl
0.05 -
1
0.1 0.1 7
mixture (vapor)............................
1
7
+Phosgene .........................................
0.1
0.4
Phthalic anhydride.......................
2
12
-H-Pival (2-Pivalyl-l,3-
indandione)..................................
-
0.1
Propane........................................... 1,000
1,800
Propylene imine - Skin................. ^ -H-Rhodium, Metal fume and dusts
2 --
5 0.1
/* ' soluble salts..............................
'V
Selenium compounds......................
^ ++$elenium hexafluoride...................
-- 0.05
0.001 0.2 0.4
Silver, metal and soluble
compounds................................... -H-Tellurium hexafluoride.................
--
0.02
0.01 0.2
1, 1, 1, 2 * Tetrachloro-2,
2 difluoroethane................... . 500
4170
-H-Tetramethyl lead (TML)
(as lead) - Skin.......................... -H-Tetramethyl
--
0.075
succinomtrile - Skin................. -HTremolite ++1, 1, 2-Tnchloroethane - Skin.
0.5
Smppcf 10
3 -
45
Xylene................................................. 100
Yttrium.............................................
-
435 1
(
18 19
EC- 2019
Appendix A
A' Benzidine. Because of high incidence of bladder tumors in man, any exposure, including skin, is extremely hazardous.
A1 /j-Naphthylamine. Because of the extremely high f*'
incidence of bladder tumors in workers handling this compound, and the inability to control ex- '
posures, /J-naphthylamine has been prohibited
from manufacture, use and other activities that in volve human contact by the State of Pennsylvania
A3 N-Nitrosodimethylamine. Because of extremely hig/"'toxicity and presumed carcinogenic potential cj this compound, contact by any route should nor be permitted,
A* polytetrqfluoroethylen** decomposition products.
At least one identified component of the de composition pioducts is extremely toxic, but in the absence of more complete toxicity in formation and suitable analytic methods, a de finite Threshold Limit Value is not recom mended at this time; but air concentrations should be minimal.
A5 /J-Propiolactone. Because of high acute toxicity and demonstrated skin tumor production in animals, contact by any route should be avoided.
c
* Trade Names; Algoflon, Fluon, Halon, Teflon, Tetian
Appendix B B. 1 THRESHOLD LIMIT VALUES FOR
MIXTURES
When two or more hazardous substances are present, their combined effect, rather than that of either indi vidually, 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,
C1 -r _C-_ -r . . Cn
T' L
exceeds unity, then the threshold limit of the mixture^ should be considered as being exceeded. Ciindicates the xobserved atmospheric concentration, and T the corres ponding threshold limit, (See Example lA.a.).
20
r
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 m fact additive, but independent as when purely local effects on different organs of the body are produced by the various com ponents of the mixture. In such cases the threshold limit ordinarily is exceeded only when at least one member of the series (fr or etc.) itself has a value
T. Tj exceeding unity, (See Example lA.b ).
Antagonistic action or potentiation may occur with some combinations of atmospheric contaminants. Such cases at present must be determined individually. Poten tiating or antagonistic agents are not necessarily harm ful by themselves. Potentiating effects of exposure to such agents by routes other than that at inhalation is also possible, e g. imbibed alcohol and inhaled narcotic (trichloroethylene) Potentiation is characteristically ex hibited at high concentrations, less probably at low
When a given operation or process characteristically emits a number of harmful dusts, fumes, vapors or gases, it will frequently be only feasible to attempt to evaluate the hazard by measurement of a single sub stance In such cases, the threshold limit used tor 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 ordi narily present.
Examples ol processes which are typically associated with two or more harmful atmospheric contaminants art welding, automobile repair, blasting, painting, lacquering, certain foundry operations, diesel exhausts, etc. (Example 2)
THRESHOLD LIMIT VALUES FOR MIXTURES
EXAMPLES
1A General case, where air is analyzed for each com ponent.
a. ADDITIVE EFFECTS
Air contains 5 ppm of carbon tetrachloride (TLV, 10), 20 ppm of ethylene dichloride (TLV,50) and
C 10 ppm of ethylene dibromide, (TLV, 25). 5 20 10 65 10 50 25 - 50 Threshold limit is exceeded.
21
EC- 2020
6. INDEPENDENT EFFECTS
Air contains 0.15 mg/m' of lead (TLV, 0.2) and 0.7 mg/m' of sulfuric acid (TLV, 1).
Q I5. _ o 75- _9'.Z.. ^07 0.20 ~ ' 1
Threshold limit is not exceeded.
IB. Special case when source of contaminant is a mixture and atmospheric composition is assumed similar to that of original material, i.e. vapor pres sure of each component is the same at the observed
rtemperature.
a. ADDITIVE EFFECTS, approximate solution 1. A mixture of equal parts (1) trichloroethylene (TLV, 100). and (2) methyl chloroform (TLV 350)
JL JL _ Jk 100 350 - T,,,
C.-C.._C,,
Solution applicable to "spot'' solvent mixture usage, where all or nearly all. solvent evaporates
c. C, 2C. 100 350 TM T,,, 7C 2C, 20. 700 700 " T,,,
T,,, - 700 x = 155 ppm
t
lBb General Exact Solution for Mixtures of N Com ponents With Additive Effects and Different Vapor Pressures
rr
r
(6,
F,P, T
+ LPJ T
+ . .. +
^F.Pf",_ _
F,P, 7,
++, 1"FT.,_, p^
+ ...+ F,P.
and solving for T,
ic ii r F.p,0 + F,p, + ... + F.p,
(6.!) T- F,p, , Fjp,
F,p;
TT, T T T i f
i--n or s (6.2) T - I _ 1
i--n i-1
F,pi'
F,p, T,
T = Threshold Limit Value in ppm
C * Vapor concentration m ppm,
p = Vapor pressure of component
in solution.
P' = Vapor pressure of pure
component.
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
Solution to be applied when there is a reservoir of the solvent mixture whose composition does not change appreciably by evaporation
By the Law of Partial Pressures, (3) C, ~ ap,,
And by Raoult's Law, ) P, - F, p,.
Combine (3) and (4) to obtain (5) C, -- af,pr.
Combining (1), (2.1), and (5). we obtain
22
t s
Exact Arithmetic Solution of Specific Mixture
Mol wt. Density T
richloroethylene (1) 131.4 1 46 g ml 100
p at 25fC
Mol frac tion m half-arid
half solu tion by volume
73mm Hg 0 527
Methylchloroform (2) 133,42 1.33 g/ml 350 125mm Hg
0.473
23
EC~ 2021
F,p, - (0.527) (73) - 38.2 F-p..' = (0.473) (125) = 59.2
T = 38.2 + 59.2 = (97.4) (350)^(97.4) (350) = 177
38.2 + 59 2 133.8 + 59.2
193.0
100' 350
T -- 177 ppm
(Note difference in T.L.V. when account is taken of vapor pressure and mol fraction m comparison with above example where such account is not taken).
f
2. A mixture of one part of (II parathion (TLV, 0.1)
and two parts of (2) EPN (TLV. 0.5).
A-
_ iA Cl> - ZC<
0.1 + 0.5 ~ T,,,
Cni " 3C,
A- , iA
3^
0.1 + 0.5 " Tm
7Cj_
0.5 " T,,,
r C
L5 Tm- 7
0.21 mg/m3
1C. T. L. V, for Mixtures of Mineral Dusts.
Foi mixtures of biologically active mineral dusts the general formula for mixtures may be used. With the ex ception of asbestos, pute minerals are assigned TLV's of 2.5, 20 or 50.
For a mixture containing 80% talc and 20% quartz, the TLV for 100% of the mixture "C" is given by:
1
TLV _ ITT--TTT " -4 mppcf 08, JL2 20 + 2.5
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 :
1 = 7.3 mppcf 0.25 , 0.25 , 0.5
2.5 ~2o" 20
( The limit for 25% quartz approximates 8 mppcf.
Appendix C
r BASES FOR ASSIGNING LIMITING "C" VALUES
By definition in the Preface, a listed value bear ing a "C" designation refers to `ceiling' value that should not be exceeded; all values should fluctuate below the listed value. In general the bases for
assigning or not assigning a "C" value rest on
whether excursions of concentration above a proposed limit for periods up to 15 minutes may result in a) intolerable irritation, b) chronic, or irreversible
C tissue change, or c) narcosis of sufficient degree to increase accident proneness, impair selt rescue or materially reduce work efficiency. In order for the Committee to decide whether a sub stance is a candidate for a "C" listing, some guidelines must be formulated on the permissive fluctuation above the limit in terms of the seriousness of the response in the categories a, D, c, given above. For this the factors given in the table below have been used by the Committee. For both technical and practical reasons, the factors have been pegged to the concentration m an inverse manner. It will be noted that as the magnitude of the T. L. V. increases a correspondingly decreased range of fluctuation is permitted; not to decrease the factor for T. L. V.'s of increasing magnitude would permit exposures to large absolute quantities, an undesirable condition, a condition that is minimized at low T. L. V.'s. More over, larger factors at the lower T. L. V.'s are con sistent with the difficulties in analyzing and con trolling trace quantities.
T.L.V.
range ppm" or mg/mJ
T eit
T.L.V. factor
Examples
c 0 to 1
3 Toluene diisocyanate-T. L. V., 0.02 ppm, if permitted to rise above 0.06 ppm may result in sensitization in a single sub sequent exposure. "C" listing
recommended on category b.
24 25
EC 2022
T.L.V,
Test
RANGE
T.L.V.
Apm` r mt/mi fctor
Examples
1 + to 10
2 Maganese-T. L. V., 5mg, mJ, contains little ot no safety factor. All values should flueuate below 5mg,'m\ "C" listing recommended on category b.
10 + to 100
1.5 Methyl styrene-T. L. V. 100 if encountered at levels of 150 ppm will prove intense ly irritating, "C" listing
recommended on category a.
f
100+ to 1000
1.25
Methyl chloroform-T. L. V. 350ppm, at 438 ppm for per iods not exceeding 15 min utes is not expected to re sult in untoward effects relating to category c. No "C" listing recommended.
(
i
* Whichever unit is applicable
As stated in the preface, the same factors may be used as guides for reasonable excursions above the limit for substances to which the time-weighted average applies. The time-weighted average implies that each excursion above the limit is compensated by a com parable excursion below the limit.
Appendix D
Some "Inert" or Nuisance Particulates
Alundum (AlzOs)
Limestone
Bentonite
Magnesite
Calcium carbonate
Marble
Cellulose
Plaster of Paris
Portland Cement
Rouge
Corundum (AIzOs)
Silicon Carbide
Emery
Starch
Glycerine Mist Gypsum Vegetable oil mists
Sucrose Tin Oxide Titanium Dioxide
(excepting castor, cashew nut,
or similar irritant oils)
Appendix E
Some Simple Asphyxiants - "Inert" Gases and Vapors.
Acetylene Argon Ethane Ethylene Helium
Hydrogen Methane Neon Nitrogen Nitrous Oxide
E. J. Baier
Harold N. MacFarland, Consultant
Allan L. Coleman E. Mastromatteo
Hervey B. Elkins Russel G. Scovrll
W, G. Fredrick
Ralph G, Smith
Bernard Grabois George W. Wright, Consultant
C Paul Gross
Mitchell R. Zavon
i Wayland J. Hayes, Jr.
Herbert E. Stokinger, Chairman
26 27
EC- 2023