Asbestos exposures associated with the use and handling of drilling mud additives

This paper summarizes historical asbestos exposure data collected during the handling of short-fiber chrysotile asbestos that was used as an additive to drilling fluid in oil and gas exploration. A total of 1171 industrial hygiene (IH) personal and area air samples were collected and analyzed from more than 20 drilling rigs between 1972 and 1985. The dataset consists of 1097 short-term samples (240 min) and there were 60 samples with no reported sample duration. Eight-hour time-weighted average (8-h TWA) results, calculated using short-term samples, along with long-term samples greater than 240 min, did not exceed contemporaneous Occupational Safety and Health Administration (OSHA) permissible exposure limits (PELs). This analysis fills a data gap in the evaluation of asbestos exposures from the use of drilling mud additives (DMAs) that contained chrysotile asbestos.