US EPA

29971 

Book/Book Chapter 

Occupational exposures to talcs containing asbestiform minerals 

Dement, JM; Zumwalde, RD 

1979 

Yes 

Cancer Letters
ISSN: 0304-3835
EISSN: 1872-7980 

NIOSH/00096325 

6 

183-192 

Worker exposures to asbestiform minerals were studied in a talc mining and milling facility in New York State. In addition, mineralogical examinations of talcs produced at the facility were performed. Personal air samples were collected from the breathing zone of miners and millers to determine time weighted average exposures to respirable dust, free silica (7631869), and mineral fibers. Talc samples contained 37 to 59 percent anthophyllite (17068789) and 10 to 15 percent serpentines. Free silica ranged from less than 0.25 percent to 2.6 percent. Calcite (16389881) and dolomite were also present in trace amounts. The highest time weighted average free silica exposure was 0.020 milligrams per cubic meter. Time weighted average exposures to fibers longer than 5 micrometers in length ranged from 0.8 to 9.8 fibers per cubic centimeter in the mine, and 0.2 to 16.0 fibers per cubic centimeter in the mill. Seventeen of 24 job categories had time weighted average exposures exceeding the current OSHA standard of 2.0 fibers per cubic centimeter, and all jobs exceeded the proposed OSHA standard of 0.5 fibers per cubic centimeters. In the mine, concentrations of asbestiform minerals ranged from 9.5 to 17.5 fibers per cubic centimeter and concentrations in the mill ranged from 9.9 to 70.6 fibers per cubic centimeter. The authors recommend that exposures to these materials be subjected to all provisions of the OSHA asbestos standard, and that warning labels be placed on all products made from asbestiform materials. 

DCN-182313; NIOSH Author; Dust exposure; Fibrous dusts; Fibrous bodies; Measurement methods; Sampling; Detection; Detection equipment; Monitors; Air sampling; Asbestos dust; 7631-86-9; 17068-78-9; 16389-88-1