Dermal absorption of benzene: implications for work practices and regulations.

Because the risk of leukemia for workers exposed to 1 ppm of benzene for 40 years is estimated to be 70% greater than the risk for unexposed persons, the National Institute for Occupational Safety and Health (NIOSH) and the American Conference of Governmental Industrial Hygienists (ACGIH) recommend that the allowable airborne exposure level be 0.1 ppm. Using an experimentally determined dermal flux (permeability) value for benzene through skin, the authors calculated the amount of benzene absorbed through a known surface area (e.g., hands) during exposures where solvents contaminated with benzene were used for cleaning. Even at current contamination levels, which are less than 0.1% in most products, the amount of benzene absorbed through the skin over a long period can be significant, depending on exposure time and exposed skin surface areas. In the example given, the risk for leukemia was increased by 42%. Therefore, the authors recommend that the liquid benzene concentration that triggers labeling, worker education, and protective measures to minimize skin exposure be reduced from 0.1% to 0.01%.

The toxicology of 1,2-dibromo-3-chloropropane (DBCP): a brief review.

The accumulating data demonstrating the reproductive toxicity of 1, 2-dibromo-3-chloropropane (DBCP) are reviewed. The sentinel event was the discovery of infertility in male pesticide manufacturing workers. In spite of early evidence of testicular damage, first in laboratory animals and later in humans, DBCP has been widely used as a nematocide in the United States and is still used in other countries. The spermatogenic effects of DBCP are usually irreversible, and there is also evidence of toxicity to the female reproductive system. DBCP is also a CNS depressant, a liver and kidney toxin, and a skin, eye, and respiratory irritant, and is probably carcinogenic. Environmental contamination of air and water may be an additional source of exposure. Materials often used to protect workers from toxic chemicals are not being deployed for use by exposed workers, and in any case are relatively ineffective.

Photoactive chemicals used in photoresist systems.

Among the most significant advances in the manufacture of microelectronic devices have been chemical changes in photoresist materials and processes. These materials should be handled with great care in the workplace. Careful medical surveillance of employees who regularly handle photoresist materials is appropriate in view of the very limited biologic information available.