Document R2746evB1j2d4bk7RJEVLrOQk
(1) AsSest'as-Cement Pipe (SIC 3292) Exposure data are available from 1375-1376 from the
CONSAQ 273 ar)(j WESTON [u] reports. Much of CONSAQ exposure data were taken from the WE57GN report.. More recent information has been provided by OSHA 28] and obtained from manufacturers during plant visits by RTI [29]. The range of time-weighted average (TWA) asbestos exposures currently found is from less than 0.1 Mf/a3 to 7 Mf/m3. A well-controlled plant has dust levels up to 1 Mf/m3 and only in finishing operations do asbestos levels even approach this 1 Mf/3 figure [29].
Process step
1975-76
1980
Exposure- level range (TWA) [23] Average [27, 28]
(Mf/m3)
(Mf/ra3)
Fiber receiving 4 storage
Fiber introduction Dry mix - wet mix Pipe formation Air cure/autoclaving Sawing Finishing lathes Coupling- cutoff 4 machining
Fittings 4. specialties Drilling Rework saw- 4 crushing Floor sweeping Quality control inspection
0.2 to 2.5a
0.1 to 4.8 0.4- to 3.0 0.1 to 1.4. 0.2 to 0.3 0.1 to 1.9 <0.1 to 0.7 0.2 to 2.3 0.5 to 2.1 <0.1 to 0.5 0.5 to 7.0 <0.1 to 0.3 <0.1 to 0.2
0.5 0.5 - 1.0 0.5 - 1.0
0.5 0.5 1.0 - 1.5 1.0 - 1.5 1.0 - 1.5 1.0 - 1.5 <0.5 1.0 - 2.0 <0.5 <0.5
ion fibers (>5pra) per cubic meter (Mf/m3).
Comparing OSHA testing data [28] and information obtained on a plant visit with average levels reported in the-WESTON repurt [11], asbestos cement pipe-manufacturers have-made improvements in reducing asbestos levels in most areas of manufacturing.
IT-18
D 003554