Ammonia concentrations in an animal inhalation exposure chamber.

Ammonia concentrations in 2.8 m3 chronic inhalation exposure chambers housing either 144 rats or 360 mice were measured by ion chromatography and chemiluminescence to evaluate chamber maintenance procedures. Variables included use of bacteriostatic cageboard, air flow rate, animal species, and age. Ammonia concentrations were lowered by using bacteriostatic cageboard and were inversely proportional to cageboard changing frequency and air flow rate.