Simulated 1,1,1 trichloroethane exposure during brake repair.
Appl Occup Environ Hyg 1996 Oct; 11(10):1177-1179
A simulation of 1,1,1-trichloroethane (71556) (TCE) exposures occurring during automobile brake repair operations was performed. The study was initiated because of a report of fulminant liver failure that required a liver transplant in a 41 year (yr) old male automobile mechanic. The patient had worked as an auto mechanic for 20yr. He worked in a garage with minimal ventilation and used no respiratory protection. Six months before the onset of liver disease he had completed many brake jobs using a variety of products containing TCE at concentrations up to 95%. In the simulation, an experienced auto mechanic repaired front disc brakes in an auto repair shop during which exposure to TCE vapor was monitored using three sampling scenarios: brake cleaning while the shop was mechanically ventilated by two wall mounted fans with one of two garage doors open (scenario-I); while the shop had only natural ventilation, both fans turned off and both doors open (scenario-II); and spraying a 24 ounce aerosol can of degreaser containing 95% TCE into a catch basin with both fans operating and both doors open (scenario-III). Personal and area air samples were collected and analyzed for TCE using a Miran infrared analyzer and charcoal tubes. Personal air TCE concentrations measured by the Miran analyzer during scenario-I, scenario-II, and scenario-III varied from 100 to 462, 100 to 1,105, and from 201 to more than 2,411 parts per million (ppm), respectively. The personal air TCE concentrations measured during the same simulations using the charcoal tubes were 86 or 87, 83 to 139, and 367ppm, respectively. Area air TCE concentrations varied from 12 to 74ppm during the simulations. The author concludes that several of the peak TCE exposures measured by the Miran analyzer exceeded the NIOSH and OSHA standards of 350 and 450ppm, respectively. These results provide additional data which show that using spray aerosols leads to elevated TCE exposures and emphasize the need for more appropriate measures to decrease occupational TCE exposures.
NIOSH-Author; Chlorinated-hydrocarbons; Case-studies; Organic-solvents; Occupational-exposure; Industrial-hygiene; Liver-disorders; Automobile-repair-shops; Simulation-methods; Industrial-ventilation
John M. Dement, Division of Occupational and Environmental Medicine, Department of Community and Family Medicine, Duke University Medical Center, Durham, North Carolina 27710
Applied Occupational and Environmental Hygiene