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TIVs
THRESHOLD LIMIT VALUES
and
BIOLOGICAL EXPOSURE INDICES
for 1985-86
American Conference of Governmental Industrial Hygienists
CBY 3102517
c 000176
LAM022086
. >
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OUSTS Substance
TLV-TWA
SILICA, SrO,
Crystalline
{ Quartz [14808-60-7]
In mppcf:"'1 300"
SJ quartz + 10
For respirable dust in mg/mJ 10 mg/m"
% Respirable quartz + 2
For "total dust," respirable and nonrespirable:
30 mg/m*
?t quartz + 3
{ Cristobolite [14464-46-1]
. Use one-half salue calculated from the count or mass formulae for
quartz.
Silica, fused
160676-86-0] { Tndymite
[15468-32-3| Tripoli . .
[1317-95-9)
0 I mg/m!. Respirable dust Use one-half the value calculated from formulae for quartz. 0.1 mg/' of contained respirable
quartz dust.
{ Amorphous [7631-86-9] 120 mppcf >
{ Precipitated silica
{(5mg/m\ Respirable dust)
" 10 mg/m1. Total dust
{ Silica gel .
{(5 mg-m'. Respirable dust) "10 mg/m . Total dust
t SILCATES and OTHER DUSTS m quamj
Asbestos'*' Amostte . [12172-73-5] Chrysotile [12001-29-5]
Crocidolite. [12001-28-4]
Other forms {Graphite (natural)
[7782-42-5] {Mica [12001-25-21 Mineral wool fiber
{Perlite . {Portland cement
. 0.5 fiber cc. Ala
2 fibers/cc. Ala
0.2 fibercc. Ala
2 fibers/cc. Ala '2.5 mg m\ Respirable dust {(5 mg/m'. Total dust) (20 mppcf) 10 mg m (30 mppcf) (30 mppcf)
34
'Soapstone................. 3 mg/m1. Respirable dust
6 mg/m1. Total dust
Talc (containing no
asbestos fibers)
[14807-96-6] .
2 mg/m'. Respirable dust
'Talc (containing
asbestos fibers)
Use asbestos TLV. However.
should not exceed 2 mg/m' respir
able dust.
Nuisance particulates (see Appendix O):
} (30 mppcf) or 10 mg/m'"" of total dust < I9f quanz. or,
{(5 mg/m' respirable dust.)
Conversion factors: mppcf x 35.3 = Million particles per cubic meter
= Particles per cc
tCOAL DUST
t (2 mg/m' (respirable dust fraction < 55c quartz) * If > 5% quartz, use respirable quartz value.
FOOTNOTES FOR OUSTS
(h) Millions of particles per cubic foot of air, based on impinger samples counted by light-field technics.
(i) The percentage of quanz in the formula is the amount deter mined from airborne samples, except in those instances in which other methods have been shown to be applicable.
(j) Goth concentration and percent quanz for the application of this limit are to be determined from the fraction passing a sizeselector with the following characteristics:
Aerodynamic Diameter (pm) (unit density sphere)
% Passing Selector
< 2.0 2.5 3.5 5.0 10
90 75 50 25 0
(k)As determined by the membrane filter method at 400-450 x magnification (4 mm objective) phase contrast
illumination. (l) Fibers longer than 5 pm and with an aspect ratio equal to
or greater than 3:1. f(m) (Containing less than 1 % quartz: if quartz content > 1 %, use
formulae for quartz.)
35
C8Y 5102513
C 000177
LAM022087