AMMONIUM SULFATE CAS N°: 7783-20-2

OECD SIDS
AMMONIUM SULFATE
5. TOXICITY ID: 7783-20-2
DATE: 18.04.2006
necessary, during preliminary experiments, to prevent
changes resulting from pneumonia (and subsequent mortality).
EXPOSURE TO TEST SUBSTANCE:
One-half of the elastase-treated animals and one-half of the
saline-treated animals were exposed to ammonium sulfate, and
the remainder were exposed to air only. Animals were exposed
and housed in Hazelton Systems Model 100 stainless-steel
exposure chambers. The chamber air flow of 0.30 m3/min
provided seven changes of filtered air per hour.
Aerosols were introduced into and thoroughly mixed with the
filtered air stream before entering the chambers. Several
Retec nebulizer generators supplied with special reservoirs
provided a constant ammonium sulfate solution concentration
and liquid level for stable aerosol generation.
Time-weighted average concentrations of aerosol were
determined from four 90-mm filter samples taken over the
daily 6-hr exposure periods. These filter samples were
analysed, chemically and gravimetrically, and corrected by
correlating the amount of particles recovered by spiked
filters with each set of samples. Daily
time-weighted-average concentrations for ammonium sulfate
were 1.03 mg/m3 +/- 0.11 SD (gravimetric) and 0.97 mg/m3 +/-
0.11 SD (chemical). Aerosol particle size was measured by a
cascade impactor (Mercer design) on samples collected over 15
hours of exposure time during a 5-day week. The MMAD was 0.42
+/- 0.05 um SD, geometric standard deviation (GSD) was 2.25
+/- 0.22.
Animals were exposed for 6 hours/day, 5 days/week, for a
total of 20 exposures. Control (air only) animals were
maintained in identical chambers under similar conditions of
air flow, temperature, humidity, cage changes, etc. All
animals were housed in similar chambers during nonexposure
periods.
At the end of the exposure period (4 weeks after
intratracheal instillations), animals were deeply
anesthetized, and the lungs perfused with 2% glutaraldehyde
solution. The lungs were removed for examination after
observation of macroscopic features in situ. Fixed lung
volume was determined by weight of displaced fluid.
Slices of approximately 1 mm were taken from both the right
diaphragmatic and left lobes of each animal and examined
under a dissecting microscope for the degree of emphysema. A
subjective rating of 0 (none observed) to 5 (total
involvement) was given to each tissue slice. The rating
(score) was determined by estimating the proportion of the
slice affected by disruptive alveolar changes and the
severity of alveolar disruption within involved areas. The
area affected was determined.
From each animal, the slice most closely approximating the
mean degree of involvement was prepared for examination by
scanning electron microscopy (SEM).
Morphometry: Chord lengths were measured across alveoli,
alveolar sacs, and alveolar ducts from photographs taken
during SEM. The median, mean, and SD were calculated for
these chord length measurements, and histograms were
developed. To ensure consistency in measurements between
photographs the criteria as developed by Busch et al.,1984
(Env. Res. 33, 497-513) were followed. In addition, alveolar
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