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Exposure related observations in humans: other data

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exposure-related observations in humans: other data
Type of information:
Adequacy of study:
supporting study
2 (reliable with restrictions)

Data source

Reference Type:
Hepatotoxicity Associated with Overexposure to 1,1-Dichloro-2,2,2-Trifluoroethane (HCFC-123)
Boucher R, Hanna C, Rusch GM, Stidham D, Swan E, Vazquez M
Bibliographic source:
Am. Ind. Hyg. Ass. J. 64, 68-79

Materials and methods

Results and discussion

Applicant's summary and conclusion

Executive summary:

8 workers exposed to HCFC-123 used as a precision cleaning agent showed marked elevations in ALT and AST after 1-4 months of exposure. The analysis of working conditions showed that 2 workers presenting liver alterations could have experienced intermittent high exposures. However, other affected workers were not operating directly with the degreaser system. Industrial hygiene sampling collected during the start-up period after introduction of HCFC-123 indicated personal samples ranging from 24-480 ppm for 375 and 21 minutes, respectively. No exposure determination was available during the time when the liver abnormalities were suspected to have developed; however, personal and area sampling collected after the finding revealed concentrations of 5-12 ppm HCFC-123. The exposure occurred prior to the finding of liver abnormality was estimated theoretically by means of 2 different models, one considering the workplace as a homogeneous box and another considering the plant divided into 2 smaller areas. In the first model a conservative estimate of air change rate 6 changes/day was assumed, whereas 12 or 28 air changes/day were considered in the second model. The first conservative simulation gave an estimated 8-h TWA concentration ranging from 10 to 35 ppm. The second model indicated that workers operating closely to the degreaser could have been exposed to daily peak concentrations ranging from 280 to 2,100 ppm and respective 8-h TWA concentrations of 252-1,630 ppm, whereas workers not working around the degreaser could have experienced peak exposures of 28-210 ppm and 8-h TWA of 25-163 ppm (Boucher et al., 2003)