Document 3XBBzypaL5zxERqRMe8y0zoO
FILE NAME: Kaiser Gypsum (KG) DATE: 1968 DOC#: KG094 DOCUMENT DESCRIPTION: Legal - TLV - Notice of Intent
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COMMITTEE ON THRESHOLD LIMITS
of thi
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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 recomme idations of tentative changes in the
I967 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 I968 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 I968 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, 1968. Address:
Dp. Herbert E. Stokinger, U. S. Public Heal :h Service, 101J+ Broadway, Cincinnati, Ohio lt-5202. If preferred, information may he 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 meeting of the Plenary Committee:
REVISIONS UNDER CONSIDERATION
SUBSTANCE Asbestos*
FROM 1967 List ppm, mg/m3 or nippef
5
PROPOSED FOR 1$68 LIST
*Appene.ix 7. A limit of 5 mppcf, based on impingor samples counted by light-field technics, is satisfactory to control ex posure: to most forms of asbestos. Crocidolite, however, has been shown to pro duce, in addition to the asbestotic in flammation, also mesothelioma. Since no safe limit can be established for this form of asbestos at this time, until more defini tive di ta are obtained, it is recommended that workers exposed to crocidolite be equipped with air-supplied masks.
-2 -
1968 NOTICE OF INTENT, continued
SUBSTANCE
FROM 1567 LIST ppm, mg/m3 or mppc E
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
Stoddard solvent Tetraethyl lead Tetramethyl lead
C 25 10
250 mppcf
10 0.5
*Downward revision by a factor
% siOo+5 10
200
id
200
of 2.5 ?
0.5
500
`0.5
_U0
5
* 5* Collected by electro
static precipitator.
If vapors involved, apply appro
1000 ^
25O mppcf Jo Si02 +5
priate TLV
500
A&
10 mg/nr % Resp. free Si02^+2
(alternative mass formula)
^Respirable free SiOg as defined by:
Areodynamic Diameter Minimal
(uiit density sphere)
$
miera
Collected
< 2.0
90
2.5
75
3.5
50
5.0
25
10.0
0
500.
0.075 0.075
200
Downward revision ?
fl
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/mr ppm ppm mg/m? mg/m?
0
> -*
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
Vrimethyl benzene
Hexafluoroisopropanol
Vinyl acetate
Dr, Herbert E. Stokinger, Chairman, TLV Committee, ACGIH
November 22, 1967