AMMONIUM SULFATE CAS N°: 7783-20-2

OECD SIDS
AMMONIUM SULFATE
Hen: a reduction in weight gain and gain/feed ratio was examined after 14 days in chicken fed with
ammonium sulfate when the concentration in food exceeded 10 000 mg/kg food. The validity of the
result cannot be assessed because of insufficient documentation of the study (Sibbald, 1976).
Conclusion
The most sensitive amphibians were the 6 week-old Pseudacris regilla tadpoles, with a NOEC
(growth, wet weight) of 82 mg/l ammonium sulfate. The corresponding LOEC was 154 mg/l
ammonium sulfate. The LC 50 (10 d) for 6 and 9 weeks old Pseudacris regilla, for Rana aura and
Ambystoma gracile was > 995 mg/l.
4.4 Initial Assessment for the Environment
Ammonium sulfate is a white solid, with a solubility in water of 764 g/l at 25 °C. When heated,
decomposition starts at temperatures between 150 and 280 °C, depending on the experimental
conditions and purity of the test substance, and is complete at 336 - 357 °C. The relative density is
1.77, and the partial pressure of ammonia over solid ammonium sulfate at 25 °C is 4.053*10 -7 Pa.
The log K OW was determined as –5.1 in a test according to OECD TG 107; as this method applies
only to substances which do not dissociate, the validity of this method for ammonium sulfate is
uncertain. Due to the ionic nature of the substance the calculation of sorption onto organic soil
matter does not have any practical meaning.
Due to the salt-character of the substance the calculation of a fugacity model and Henrys Law
Constant is not appropriate. Based on the physico-chemical properties of ammonium sulfate, water
is expected to be the main target compartment.
Although ammonium sulfate does not volatilize, it can, especially if applied on the soil surface,
decompose in soil to release ammonia, which will volatilize. Although ammonium sulfate can be
created in the atmosphere from ammonia and sulfur dioxide, this process is limited by atmospheric
sulfur dioxide, not by ammonia, which has many natural sources. Particulate ammonium sulfate is
removed from air by wet and dry deposition. There is no evidence for photodegradation of
ammonium sulfate.
In unsterilized soil, ammonium sulfate is mineralized fairly rapidly, and subsequently nitrified.
Nitrification and de-nitrification processes also occur naturally in streams and rivers, as well as in
many secondary sewage treatment processes. Based on high water solubility and the ionic nature,
ammonium sulfate is not expected to adsorb or bioaccumulate to a significant extent. However,
mobility in soil may be reduced through ion-ion interactions.
Environmental effects can be assessed in the freshwater and marine environments. In addition,
some information is available for soil and sewage treatment micro-organisms, for freshwater
sediment, and for the terrestrial environment.
Freshwater Environment
The lowest acute and chronic toxicity values for the three trophic levels for which freshwater
ammonium sulfate data is available are shown in Table 7.
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