Document N2Xw2nZgL71oOyNk6EVywrOpV
FILE NAME: Kaiser Gypsum (KG) DATE: 1968 DOC#: KG094 DOCUMENT DESCRIPTION: Legal - TLV - Notice of Intent
COMMITTEE ON THR5SHOID LIMITS
of th
44
AMERICAN CONFERENCE OF GOVERNMENTAL INDUSTRIAL HYGIENISTS
1968 NOTICE OF IN CENT
This Notice of Intent is published so that Industry-connected individuals prin
cipally, but others also, may have an oppor:unity to help shape the delibera
tions of the Committee prior to its recommeldations of tentative changes in the
1967 Threshold Limits List. This can be doie by submitting to the Chairman
comments on the intended changes, with supporting data, or by submitting new
data on substances not within the Notice of Intent.
This Notice is not binding on the Committee to place all substances listed below
in the 1968 Edition, nor does it restrict the Committee to these substances; sub
stances with appropriate supporting data received following the publication of this list will be considered at the next Committee meeting for inclusion in
the 1968 Edition. This Notice indicates on .y those substances that are under
consideration by the Committee. Documentt .on is available upon request for those substances bearing a threshold limit value.
All comments should reach the Chairman by March 15, I968. Address*
Dp. Herbert E. Stokinger, . S. Public Health Service, lOlU Broadway, Cincinnati, Ohio 1+5202. If preferred, information may 1e sent to the Repository of Anonymous Occupational Health Data, c/o Dr. R. T. P. de Treville, Industrial Hygiene Foundation, U400 Fifth Avenue, Pittsburgh, Pennsylvania 15215.
The following list of Proposed Revisions and Additions for the 1968 Threshold
Limits List has resulted from the fall meet:.ng of the Plenary Committee:
REVISIONS UNDER CONSIDERATION
SUBSTANCE Asbestos*
FROM 1967 List 5
PROPOSED FOR 1968 LIST ppm. mg/m5 or mppcf
*Appenc.ix 7. A limit of 5 mppcf, based on impingor samples counted by light-field technics, is satisfactory to control ex posures to most forms of asbestos. Crocidolite, however, has been shown to pro duce, i n addition to the asbestotic in fiammai ion, also mesothelioma. Since no safe limit can be established for this form of asbestos at this time, until more defini tive de ta are obtained, it is recommended that workers exposed to crocidolite be equipped with air-supplied masks.
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1968 NOTICE OF INTENT, continued
SUBSTANCE ________________
FROM I967 LIST
ppm, mg/m5 or mppcE
PROPOSED FOR I968 LIST
ppm, mg/m^ or mppcf
Benzene Butyl mercaptan Cristobalite*
Tridymite* Ethyl mercaptan Heptane Methyl mercaptan Octane Oil Mists*
Pentane Petroleum distillates Quartz
c 25
10
250 mppcf
10
0.5 Downward revision by a factor
% S iOh+5
of 2.5 ?
10
0.5
200
500
10
`0.5
200
Uoo
5
" 5* Collected by electro
static precipitator.
If vapors involved, apply appro
1000,,
250 mppcf
priate TLV
500
A&
10 mg/mr
$ SiOg +5
$ Resp. ree SiC>2*+2
(alternative mass formula)
Respirable free SiOg as defined by:
Areodynamic Diameter Minimal
(uiit density sphere)
%
micra
< 2.0
Collected
90
2.5
75
3.5
50
5.0
25
10.0
0
Stoddard solvent Tetraethyl lead Tetramethyl lead
500. 0.075 0.075
200
Downward revision ?
Il
II
SUBSTANCE
ADDITIONS UNDER C 3NSIDERATI0N PROPOSED LIMIT
Dichloroace tylene Endosulfan (thiodan) Indene Methyl isoamyl alcohol Pentaerythritol Rosin fumes
skin
C 0.1 0.1
10 100
15 0.2
ppm mg/nP ppm ppm mg/nP mg/nP
' J
3 -
1968 NOTICE OF INTENT, continued DESIRABLE SUBSTANCES FOR ADDITION, BUT FOR WHICH INADEQUATE DATA EXIST
Information pertinent to the recommendation of an industrial air limit is solicited on the following substances :
Aluminum powder
]fercaptobenzothiazole
Benzothiazyl disulfide
(;oly) vinyl chloride
Butyl lactate
Silicon tetrachloride
o-Chlorostyrene
Silicon tetrafluoride
Hexafluoroacetone
"rimethyl benzene
Hexafluoroisopropanol
Vinyl acetate
Dr, Herbert E. Stokinger, Chairman, TLV Committee, ACGIH
November 22, 1967