Document LqV34akN730oqD7KX0DmVkzX
PLAINTIFF'S EXHIBIT
Threshold Limit Values
lor '
'
v.;.*a &
Chemical Substances
and
Physical Agents
in the
Workroom Environment
with
Intended Changes
for
1979
C 000166
CBY 3102507
LAM022076
2. Maximum Permissible Body Burdens and Maximum Permissible Concentrations of Radionuclides in Air and in Water far Occupational Exposure." US Department of Commerce, National Bureau of Standards Handbook 69, issued June 5. 1959. with Addendum 1 issued August 1963. Available as NCRP Report No. 22. The above documents, as well as information on nu merous other NCRP Reports addressing specific sub jects in ionizing radiation protection are available from: NCRP Publications. PO Box 30175. Washington. DC 20014.
Substance SIUCA, S/O;
MINERAL DUSTS
Crystalline Quartz
TLV in mppcf 300'"
% quartz +10 TLV .lor respirable dust in mg/m3:
10 mg/m3"
% Respirable quartz + 2 TLV for "total dust." respirable and nonrespirable:
30 mg/m3
% quartz - 3
Cristobairte.
Use one-half the value calculated
from the count or mass formulae
for quartz.
Tridymrte
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, all forms
Mica Mineral wool fiber
(5 fibers/cc > 5jtm in length"; Ala)
20 mppcf 10 mg/m3
"See Notice of intended Changes
32
. -.i .j'.ngw
.1 JUlL.JNIil,
Perlite Portland Cement Soapstone Talc (nonasbestiform) "Tate (fibrous), use Asbestos limit.
"Tremolite. see Asbestos.
30mppcf 30mppcf
20mppcf 20mppcf
COAL DUST
2 mg/m3 (respirable dust fraction < 5% quartz). If > 5% quartz, use respirable mass formula.
NUISANCE PARTICULATES
(see Appendix E)
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-lield technics.
h) The percentage of quartz in the formula is the amount determined from airborne samples, except tn 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 (/am) (unit density sphere)
s2 2.5 3.5 5.0 10
% passing selector 90 75 50
25 0
l) 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
"Sec Nonce ol Intended Changes
33
CBV 3102508
C 000167
LAM022077