Design and performance of a system for blood collection of rats under whole-body inhalation exposure

In order to obtain basic risk assessment data on human health exposure to volatile organic compound (VOC) vapor by inhalation, a whole-body inhalation exposure system which allows blood collection during the exposure period was designed. The system was tested using chloroform as a model VOC. Chloroform vapor, sampled from the supply-header, animal-chambers and exhaust-header, remained constant in this system with variations in its concentration being less than 2%; flow rate of the vapor through the system was also constant. Rats were exposed to chloroform vapor and blood collected from the tail during exposure to the chloroform vapor. The chloroform concentration in the blood increased during the initial 60 min of exposure, and afterwards its concentration remained at about 2 microg/ml from 60 to 360 min. In conclusion, our design allows blood to be collected from individual rats during exposure by inhalation to test VOCs and changes in the blood concentration of the VOC during exposure to be assessed.