This paper discusses some basic principles of allergy and asthma, and provides an overview of laboratory animal allergy and aeroallergen quantitation methods. Laboratory animal worker exposures to total and respirable particulate concentrations were determined from personal samples (both time-weighted average and task specific) and area samples. All results were below threshold limit values for nuisance dust (10 mg/M^3-total, 5 mg/M-^3-respirable) and hardwood dust (1 mg/M^3). The highest particulate exposures existed in the area on the clean side of the automatic cage washers (0.97 mg/M^3-total, 0.05 mg/M^3-respirable, TWAs) where hardwood bedding chips were dispensed into clean cages. The respirable percent of the samples varied widely (5 to 100%). The air samples collected will be analyzed by RAST inhibition for rat urinary protein and rat dander, and will be used for dose determination in a prospective study on the development of laboratory animal allergy and asthma. A system of dose calculation and data presentation is suggested for the follow-up epidemiology.