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PLAINTIFF'S EXHIBIT
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Threshold Limit Values
for
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Chemical Substances
and
Physical Agents
in the
Workroom Environment
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for
CBY 3102511
C 000170 LAM022080
a.
Substance SILICA, S/0;
MINERAL DUSTS
Crystalline Quartz
TLV in mppcf"': 300'"
% quartz + 10 TLV for respirable dust mg/m3:
10 mg/m3"
in
% Respirable quartz + 2 TLV for "total dust," respirable and nonrespirable:
30 mg/m3
% quartz + 3
Cnstobalite........... Use one-half the value calculated
from the count or mass formulae
for quartz.
Tridymite
Use one-half the value calculated
from formulae for quartz.
Silica, fused
Use quartz formulae.
Tripoli
Use respirable'" mass quartz for
mula
**Amorphous........ ............................... (20 mppcf"')
SILICATES (< /% quartz)
Asbestos Amosite................... 0.5 fiber > 5/im/cc, Ala Chrysotile................. 2 fibers > fyim/cc, Ala Crocidolite................ 0.2 fiber > 5^m/cc, Ala Other forms............. 2 fibers > 5/um/cc, Ala
Mica............................ 20 mppcf Mineral wool fiber........ 10 mg/m3 Perlite.......................... 30 mppcf Portland Cement........... 30 mppcf Soapstone ................... 20 mppcf Talc (nonasbestiform)... (20 mppcf)
Talc (fibrous), (use As
bestos limit.)
` `See notice of intended charges
32
i.?.
COAL DUST
2 mg/m3 (respirable dust fraction < 5% quartz). If > 5% quartz, use respirable mass formula.
NUISANCE PARTICULATES (see Appendix O)
30 mppcf or 10 mg/m3" of total dust < 1% quartz, or, 5 mg/m3 respirable dust.
Conversion factors: mppcf x 35.3 = Million particles per cubic meter = particles per cc
g) Millions of particles per cubic foot of air, based on impinger samples counted by light-field technics.
h) The percentage of quartz in the formula is the amount determined from airborne samples, except in those instances in which other methods have been shown to be applicable.
i) Both concentration and percent quartz for the appli cation of this limit are to be determined from the fraction passing a size-selector with the following characteristics:
Aerodynamic Diameter (^m) (unit density sphere)
s2 2.5 3.5 5.0 10
% passing selector 90 75 50 25 0
j) containing < 1% quartz: if quartz content > 1%, use formulae for quartz.
k) Lint-free dust as measured by the vertical-elutriator, cotton-dust sampler described in the Transactions of the National Conference on Cotton Dust, J. R. Lynch, pg. 33. May 2, 1970.
l) As determined by the membrane filter method at 400-450X magnification (4 mm objective) phase con trast illumination.
m) Based on "high volume" sampling. n) "Respirable" dust as defined by the British Medical
Research Council Criteria (1) and as sampled by a device producing equivalent results (2). (1) Hatch, T. E. and Gross, P., Pulmonary Deposi
tion and Retention of Inhaled Aerosols, p. 149.
33
i
CBV 3102512
C 000171
LAM022081