Abstract
A new and innovative portable system, allowing for the exposure of up to 24 mice to chemical vapors for a period of at least 4 hours, is presented. With this apparatus, mice can be selectively exposed to a chemical agent strictly by the dermal route or by inhalation. Specially designed animal cassettes or holders containing slots in the rear portion were developed for use in this system. These slotted areas in the holders provide adequate ventilation and permit mice to be exposed dermally to test substances. Operating parameters of the exposure system were evaluated with test atmospheres of ethylene dichloride (EDC). Distribution of vapor in the chamber was tested for 2 different concentrations of EDC, 500 ppm and 1200 ppm. Vapor distribution was found to be uniform throughout the chamber for both concentrations. The capability of the exposure system to maintain a consistent desired test atmosphere over a 4-hour period was also investigated. EDC was used at concentrations of 900 and 1000 ppm, and it was demonstrated that the EDC concentration varied by no more than ±8% over the test period. Thus, this exposure chamber represents an inexpensive, uniform, portable system for conducting inhalation or dermal exposure studies with selected contaminants that might represent a potential chemical hazard.