The scientific validity of the standards for 1,2-dibromoethane

Abstract

1,2-Dibromoethane (DBE) is a nematocide used extensively to control fruitfly and other larvae that feed on fruit and grain and as a lead scavenger in gasoline additives. DBE is extremely toxic to animals at relatively low doses and is carcinogenic in chronic animal studies on mice and rats. The lack of good human epidermiologic data resulted in the reliance of quantitative risk assessment techniques by the Environmental Protection Agency (EPA) for severely limiting its use as a fumigant for grain in 1984, and the Occupational Safety and Health Administration (OSHA) for lowering workplace standards from 20 parts per million (ppm) to 0.1 ppm. This thesis reviews the metabolic, animal, and human studies used for the extrapolation, the mathematical models available, the assumptions made for the data and model chosen, and discusses the validity of the resultant process for setting standards for DBE exposure.