A new inhalation exposure system for the determination of inhaled doses in laboratory rats

A new inhalation exposure system has been developed which allows the determination of inhaled doses of vapors and gases by laboratory rats. The system consists of saran bags connected to head-only exposure cylinders via one-way valves. One bag serves as the source of contaminant and another receives expired air. The exposure cylinders also serve as whole body plethysmographs. Up to three rats can be exposed concurrently to the same concentration of test material. The construction of the system and its use for inhalation exposures to a direct-acting radiolabeled carcinogen are described.