Document 2j7Y6dabr851mnVndqje9Kj3L
PLAINTIFF'S
EXHIBIT
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Transactions of tnc
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. MPOHT OP THE COBIITTEE OH THRESHOLD LIMITS _
DR. L. T. PAIRBALL (D. S. Public Health Service)] It is obviously difficult,
where a large number of substances is involved, to review the maximum allowable
concentration values in detail at an annual nesting. Fbr that reason, provision
was nade early in the organisation of the American Conference of Governmental In
dustrial Hygienists for a Committee on Threshold Limits to study this question and
to report to the'Conference at its annual meeting. The composition of this Com
mittee is not fixed but is changed by annual appointment and the threshold limit
values are similarly maintained in a fluid state by annual revision. For a number
'of years the Cosmittee has subjected these values to oereful scrutiny and attempted
to bring them into olose conformance with practice.
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" ` During the present year, it was folt that the eonoept of maximum allowable
values had now reached a stage where more extensive participation of the members
of the Conference in the formuletion of these values based upon personal experience
in the field would be of deoided assistance. This year, therefore, your Committee
has for the first time, I believe, made a direct attempt to obtain a statement
from each member of the Conference with roferenoe to tho annuel threshold limit
values end the response from the individual members has been most generous and
helpful.
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/ tji nf pose of the
nnnti i*mH-inn nf threshold limit values,it hos been the pur
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wini>. inih) m
pn* hand protect the individ-
ual~worV"n- "d on the other would impose no impossible burden on the manufac
turer. This balance is difficult to achieve but con be attained by just such a
series of adjustments as is provided for in the Constitution of the Conference, i There is no industrial poison so potent, so virulent, that it eannot be manufac-
j tured safely under carefully controlled conditions. The manufacture and wide-
j spread use of such a substanoe as lead tetraethyl and the preparation of extremely l poisonous war gases are good illustrations of this. In faot, the chemical manu
facturing industry in general has been able to maintain a high standard of safe
industrial practice by the installation of suitable eontrol measures for the pro tection or its workers. There is no reason why such safe industrial control
measures cannot bo extended to industry in general wherever industrial poisons
occur.
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' In addition to the eonmonts of tho members of tho Conference, a few criti-
' cisms from other sources have reached ust oonoerning tho 1947 values. Those may
' be briefly summarised as follows>
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1. Concerning the membership at large, criticism has taken the form that (a) values were arrived at by consulting tho membership at large, and (b) that the members were not consulted.
2. The publication of the values in the Industrial Hygiene N ewsletter made
- it appear that the values were those of the U. S. i>ublic Health Service. TJhether
' "this was wishful thinking or not, the source of the 1947 values was dearly in
' dieated at tho time of publication. ------ ---.. ...
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.3. Criticism has olso taken the form that the values given wero not arrived *v. or based upon scientific evidence. The latter has particularly interested
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. your present Cosnittee. No specif ie "scientific evidence" has so far been pre
sented
for
our
consideration
along
w
.
with
this
criticism*
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While it will doubtless be very advantageous to have what slight be called
; permanent or standard maximum allowable eonomtration values, it must be borne in
mind that all our values at the present time are fluid and subject to annual re-
i vision* They should not be adopted as fixed or legal values, but meroly as guides
to assist us in defining more or less safe working conditions. It is felt that
eventually definite values oan be .established which will give full and ample pro
tection to the worker. *.
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The following changes have been st^de.in the values from those of the 1947
conference*
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. Bentene has been decreased from SO to S5t ppm .
.
Chlorine has been decreased from 2.to 1 ppm '
.... . -
Formaldehyde has been decreased from 10 to S ppm
Hydrogen chloride has been .decreased from 10 to 5 ppm
' Hydrogen eyraide hrs been deereased from 20 to 10 ppm
' Hydrogen selenide has been decreased from 0.10 to 0.0S ppm
Trichloroethylene has beat deereased from ISO to 100 ppm
.. Iodine has been changed from .1 mg./cu.m, to 1 ppm
" _ ' 2-Butnnone has-been increased from-200 to 250 ppm '
. .................'. Isbpropyl'ether has been increased.from 400 to 500 ppm'
Antimony has been increased from 0.1 mg./cu.m.,to 0.5 Arsenic has been increased' from 0.1 mg./eu.m to. 0.5
.
Sulfuric acid has been increased from 0.5 mg./cu.m. to 1.0
It must be borne in Blind that these values are not'indices of toxicity and
are not intended to aporoach that value. Accordingly, the oosmaratlvw toricity
of these compounds eannot be established on the basis of their numerical maximum
allowable concentration value.
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p^nnla imry
d"T" "nd toxic substanoea-.__ Therefore.,
it is a figment
th
thlnV
we can set down a precise limit
below which there is complete anfety and ^mediately above which there mav be a
high percentage of cases of poisoning imt those exposed. .... "
wlth
<n Comn<t< hn get values below which it is fair
to expect reasonable protection and above whioh it is reasonable zo expect chat
i?e~oan have occasional eases of^poisonina.
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' THRESHOLD LIMIT VALUES ADOPTED AT APRIL, 1948, MEETING OF AMERICAN CONFERENCE OF GOVERNMENTAL INDUSTRIAL HTGIBUSTS IN BOSTON, MASSACHUSETTS
4: v'. Ethyl. c
-
^:-iv SUBSTANCE
v Acetaldehyde Aoetio aoid
Aoetio anhydride Acetone
GASES AND VAPORS
>. '
P.P.U.
r- SUBSTANCE
200 Aorolein in- 10 Acrylonitrile rther4
6 kjnrnrm GOO -Amyl acetate
P.P.U.
0.5" 20 ; 100 1 200
SUBSTANCE
P.PJt.
- . SUBSTANCE
' P.P.M.
.iso-Amy1 alcohol
- V loo
Ethyl fonaatc . . -
.. 100
...Aniline .
s Ethyl silicate
' 100
lArsine
'
^ 0.05 Formaldehyde
' * s
Benzene (benzol)
~ - 56
Gasolene
-' -
600
'`Bromine
..
:i
Heptane .
* 500
.|1,3-Butadiene "
:1,000
Hexane
500
n-Butanol
so
Hydrogen chloride
.
."
5
2-Butanone n-Butyl acetate
___2S0 - 200
Hydrogen cyanide Hydrogen fluoride
'
10 3
Butyl oelloeolTe
200 Eydrbgen selenide
0.05
Carbon dioxide
6,000
HydPogen sulfide
20
Carbon disulfide
20 Iodine
1
Carbon monoxide Carbon tetrachloride
r\ - * 100 60
Isophorone Mesityl oxide '
-
25 50
Cellosolve
' ` ;.v - 200
Methanol
200
Cellosolve acetate
- - ' 100
Methyl acetate
200
Chlorine -
'
" 1 Methyl bromide
-
20
2-Chlorobutadiene
' 25 Mothyl butanone
10Q
Chloroform
1-Chloro-l-nitropropan e
Cyclohexane
Cyclohexanol
-'
Cyclohexanone
Cyolohexene
-
Cyclopropane (propene)
o-Dichlorobenzene
Diohlorodifluorone thane
1.1-Dichloroethane
1.2-Dichloroethane (ethylene
dichloride)
1.2-Dichloroethylene
"v
Dichloroethyl ether / '^
Diehloromethane
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Dichloromonofluoromethane
1.1-Dichloro-l-nitroethane
-- 100 20
400 -. 100 -vlOO -400
400 SO
1,000 100
75 ' 200 - 16
600 1,000
10
Methyl cellosolve
25 :
Methyl oellosolve acetate
25
Methyl chloride
' 100
Methylcyolcbexane
600
Methylcyclohexanol
100
Methylcyclohexanone
100
Methyl formate
100
- Methyl iso-butyl ketone
100
. * Monochlorobenzene Monofluorot richloromethene
75 1,000
Monon itrotolu ene
5
Naphtha (coal tar)
200
Naphtha (petroleum)
600
Nickel carbonyl
-
1
Nitrobenzene
1
Hitroethane
'" `
100
Nitrogen oxides (other than N^O) 25
1.2-Dichloropropane
Nitroglycerin
'
0.5
(propylene dichloride)
76
Mitromethane
'" "
100
Dichlorotetrafluoroethan e
1,000
2-N itropropene
50
Dimethylaniline
5 Octane
500
Diaethylsulfate
. 1 Ozone
1
Dioxene
100 Pentone -
- 1,000
Ethyl acetate
400 Penton one (methyl propenone)
200
u Ethyl alcohol ' Ethyl benzene ''Ethyl bromide
Ethyl chloride
J ,. . A > '
'1,000
J 'i
-
200
200
1,000
Phosgene Phosphine
^as ?v.v.-v. t ... .
phosphorus trichloride
Iso-Propanol
.
_-** 1 , 0.06
' 0.5
<00
Ethylene chlorohydrin
Ethylene oxide
-
Ethyl ether ocr
6 * 100
400 I
Propyl acetate iso-Propyl ether ' feiibine .~L
* : . 200 '..T- ... . ;> 500
' 0.1
A
V
\
J
SUBSTANCE
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#
GASES JWD VAPORS (eont'd.)
. P.P.U.
- ' : SUBSTANCE
P.P.M.
Stoddard solvent
, lJ.^SOO
. Toluene
A. - -
Styrene monomer
- .
200 / Toluidine
' :'/
Sulfur chloride
.
. . Trichloroethylene
Sulfur dioxide
/
1,1,2,2-Tetrachloroethane
.- !/*~- IQ0e
*
: Turpentine Vinyl chloride
."
`Vf r .
Tetrachloroethylen*
'`"'loo. jyide
- '
- .200
' -5 100 100 500
200
SUBSTANCE
TOUC DUSTS. JFUUES AMD lilSTS
. Ug. per eu. m.
.
SUBSTANCE
Mg. per eu. a.
Antimony
0.5 - Mercury
..
Arsenic
0.5 Pentachloronaphthalene
Barium
-
0.5
Pentacnlorophenol
-?
Cadmium Chlorodiphenyl"
0.1 Phosphorus (yellow) .. Q. . -- Phosphorus pentachloride
Chromic acid and chromates as Crc^O.l
Phosphorus pentasulfide
Cyanide as CM
Selenium, as Se
Dinitrotoluene
1.5 . Sulfuric aoid
Fluoride
2.5 Tellurium
. .
Iron oxide fume
15 Tetryl
Lead
"'
0.15
Triehloronaphthal ene
Magnesium oxide fume
15 Trinitrotoluene
Manganese
. 6 Zino oxide fume
.
0.1 0.5 0.5 0.1 1 1 0.1 1.0 0.1 1.5 5 1.5 15
MINERAL BUSTS
SUBSTANCE
M.P.P.C.P.
SUBSTANCE
M.P.P.C.P.
Alundun
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Asbestos Cerborundum
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Dust (nuisance, no free silioa)
Mica (below 5% free silica)
Portland eenent
'
Talc
60
5.
SO 50 60 60 20
Silica: high (above 50% free Si0) medium (5 to 50% free Sityt) low (below S% free SiOg)
Slate (below S% tree SiOg) .
Soapstone (below S% tree SiQg) Total dust (below 6% free SiOg)
5 20 50 50
20 50
MATERIAL OR RaDIAIICN
RADIATIONS
Radiant fEnergy
Radiant MATERIAL OR RADIATION Energy
Gemma (roentgen per day)
'
Radon (curies per cubic meter)
0.1 10-8
Thoron (curies per cubic moter) IQ'8
2-ray (roentgen per day)
. - 0.1
~ V - I. r ;$*<' '.-.1s t*:--
,-*'. A*** - * ^_v.'-:ciI.TV-..u... * % *..
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- /*/ r
/ / f* A- >
A
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(The report of the Conmittee on Threshold Limits was accepted.)
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