CAS RN:1332-21-4

Threshold Limit Values

8 hr Time Weighted Avg (TWA): 0.1 fibers/cc. Respirable fibers: length greater than 5 um; aspect ratio greater than or equal to 3:1, as determined by the membrane filter method at 400-450X magnification (4-mm objective), using phase-contrast illumination. /Asbestos, all forms/
Peak Exposure Recommendation: Transient increases in workers' exposure levels may exceed 3 times the value of the TLV-TWA level for no more than 15 minutes at a time, on no more than 4 occasions spaced 1 hour apart during a workday, and under no circumstances should they exceed 5 times the value of the TLV-TWA level. In addition, the 8-hour TWA is not to be exceeded for an 8-hour work period. /Asbestos, all forms/
A1; Confirmed human carcinogen. /Asbestos, all forms/
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