Volume I - Section I - Introduction 
Page 1-9 
• Ammonia: Microenvironmental ammonia concentration ranged from 0 to 410 ppm, 
depending on the bedding type and day of measurement. The cages containing aspen 
shavings had a significantly higher 7-day mean ammonia concentration compared 
with other beddings. Additionally, the cages containing reclaimed wood pulp and pine 
shavings had a significantly higher 7-day mean ammonia concentration compared 
with other beddings, with the exception of aspen shavings. Cages containing virgin 
pulp loose bedding had a significantly higher 7-day mean ammonia concentration 
compared with the cages that had virgin cellulose and corncob bedding. Ammonia 
was first detected in cages containing aspen and pine shavings on day 2. On day 3, 
ammonia was first detected in cages containing reclaimed wood pulp. Cages with 
virgin loose pulp and hardwood chip bedding had detectable ammonia beginning on 
day 4, followed by the cages with recycled paper bedding on day 6. The cages 
containing virgin cellulose bedding had no detectable ammonia production until day 
7, whereas the cages with corncob bedding never had detectable ammonia 
concentration. There was a significant difference in ammonia concentration in cages 
with different bedding and the day of evaluation, indicating that ammonia production 
differed among the beddings over time. 
R.G. Maghirang, G.L. Riskowski, L.L. Christianson, and Paul C. Harrison: Development Of 
Ventilation Rates and Design Information for Laboratory Animal Facilities , Part 1 -Field Study, 
1995, ASHRAE Transactions, V. 101, Pt. 2, RP-730. 
A survey was conducted of 46 laboratory animal rooms (33 rat rooms, 8 mouse rooms, 2 
rabbit rooms, 2 primate rooms, and 1 dog room) at three commercial use sites, five 
universities, and a research organization. Air exchange rates, air velocities, temperature, 
humidity, ammonia concentrations, noise levels, and light levels were measured 
throughout the room and within selected cages in the room. Cage conditions varied 
widely among cages within the same room and among similar cages in different rooms. 
Cage type was the most important factor that influenced cage conditions and uniformity 
in cage conditions. Room air exchange rate had little influence on cage conditions. 
Velocity approaching the cage, number of returns and diffusers, and diffuser type did not 
significantly influence cage conditions and uniformity in cage conditions. 
The following conclusions were drawn: 
• Cage conditions varied widely among cages within the same room and among similar 
cages in different rooms. 
• Cage type was the most important factor that influenced cage conditions and 
uniformity in cage conditions. 
