Document rxQ80YNXBOYYvG0azZnJdML67
FILE NAME Threshold Limit Values TLV
DATE 1968 DOC TLV007
DOCUMENT DESCRIPTION Committee on Threshold Limits - 1968 Notice of Intent
'
COMMITTEE ON THRESHOLD LIMITS
of the
5
.
AMERICAN CONFERENCE OF GOVERNMENTAL GOVERNMENTAL INDUSTRIAL HYGIENISTS
1968 NOTICE OF INCENT
This Notice of Intent is published so that connected individuals principally but others also may have an opportunity to help shape the deliberations of the Committee prior to its recomme ulations of tentative changes in the
1967 Threshold Limits List This can be do 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 10 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 Corrittee meeting for inclusion in
the 1968 Edition This Notice indicates on those substances that are under
consideration by the Committee on Documentat is available upon request for those
substances bearing a threshold limit value
All comments should reach the Chairman by March 15 1968. Address
Dr. Herbert E. Stokinger U. S. Public Health Health Service 1014 Broadway Cincinnati
Ohio 45202. If preferred information may be sent to the Repository of Anonymous
Occupational Health Data / Dr. R. T. P. de Treville Industrial Hygiene Foundation 4400 Fifth Avenue Pittsburgh Pennsylvania 15213
The following list of Proposed Revisions and Additions for the 1968 Threshold
Limits List has resulted from the fall meet of the Plenary Committee
SUBSTANCE SUBSTANCE
Asbestos
REVISIONS UNDER IDERATION
FROM 1967 List
ppm mg or mppcf
5
PROPOSED FOR 1968 LIST
ppm mg or mppcf
Appendix 7. A limit of 5 mppcf based on
impinge samples counted by field technics is satisfactory to control ex-
posure to most forms of asbestos Cro-
cidolite however has been shown to produce it addition to the asbestotic inflammation also mesothelioma Since no
safe linit can be established for this form of asbestos at this time until more definitive data are obtained it is recommended
that workers exposed to crocidolite be equipped with supplied masks
1968 NOTICE OF INTENT continued
SUBSTANCE
FROM 1967 LIST ppm mg or mppe E
PROPOSED FOR 1968 LIST
ppm mg
or mppcf
Benzene
Butyl mercaptan Cristobalite
Tridymite
Ethyl mercaptan Heptane Methyl mercaptan
Octane
Oil Mists
Pentane Petroleum distillates
Quartz
C 25
10 250 mppcf
% 5102
10 200
10
200
5
1000 ,
250 mppc
% S102 +5
10
0.5 Downward revision by a
of 2.5 ?
factor
0.5
500
0.5 400
* Collected by electro-
static precipitator
If vapors involved apply appro-
priate TLV
500
A6
10 mg
% Resp free 102 alternative mass formula
Respirable free Si-as defined by
Arcodynamic Diameter
Minimal
unt density sphere
%
micra
Collected
< 2.0
90
2.5
75
3.5
50
5.0
25
10.0
)
Stoddard solvent
500
200
Tetraethyl lead Tetramethyl lead
0.075 0.075
Downward revision
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ae aeeaees e ee wee ee s s
SUBSTANCE
ADDITIONS UNDER CONSIDERATION CONSIDERATION PROPOSED LIMIT
Dichloroacetylene
Endosulfan thiodan - skin
Indene
Methyl isoamyl alcohol Pentaerythritol
Rosin fumes
C 0.1 0.1
10
LOO =
15
0.2
ppm
mg
ppm
sppm
mg m
1968 NOTICE OF INTENT continued
DESIRABLE SUBSTANCES SUBSTANCES FOR ADDITION BUT FOR WHICH INADEQUATE DATA EXIST
Information pertinent to the recommendation recommendation of an industrial air limit is
solicited on the following substances
Aluminum powder
Mercaptobenzothiazole Mercaptobenzothiazole
Benzothiazyl disulfide
Poly vinyl chloride
Butyl lactate
licon tetrachloride
Chlorostyrene
Silicon tetrafluoride
Hexafluoroacetone
rimethyl benzene
Hexafluoroisopropanol
Vinyl acetate
Dr. Herbert E. Stokinger Chairman TLV Committee ACGIH
November 22 1967