Ammonium hydrogensulphite

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

no hazard identified

Marine water

Hazard assessment conclusion:

no hazard identified

STP

Hazard assessment conclusion:

no hazard identified

Sediment (freshwater)

Hazard assessment conclusion:

no hazard identified

Sediment (marine water)

Hazard assessment conclusion:

no hazard identified

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

no hazard identified

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Conclusion on classification

Studies on the aquatic toxicity of ammonium hydrogen sulfite are not available, and thus, read-across to sulfite/disulfite and thiosulfate substances and ammonium cations is applied.Upon contact with water, salts of sulfur oxyacids including ammonium hydrogen sulfite dissociate into sulfur oxyacid anions and the respective counterions.

Ammonium is a natural component of the environment and found in soil, air, and water.Ammonium is essential for many biological processes, serves as a precursor for amino acid and nucleotide synthesis and provides e.g. a source of nitrogen for plants. Ammonium is produced by bacteria in water and soil from decomposition of organic matter, including plants, animals and animal wastes. Ammonium goes through biochemical transformations in soil and water as part of the nitrogen cycle, is rapidly degraded, i.e. mineralized by numerous species of bacteria, and therefore not expected to accumulate in the environment. Based on acute and chronic effect concentrations, fish, aquatic invertebrates and algae do not appear to be sensitive at concentrations around short- and long-term aquatic hazard classification criteria of Regulation (EC) No 1272/2008.

Acute and long-term toxicity data for sulfite/disulfite and thiosulfate substances are available for three trophic levels. The lowest LC/EC50 for fish, crustacean or algae is a 72-h ErC50 of 36.8 mg SO32-/L (based on sulfite), observed for the effect of disodium sulfite on the growth rate of Desmodesmus subspicatus in a guideline test (BASF, 1989). However, a pH decrease was observed at the level of the derived EC50 so that it cannot be excluded that observed toxicity was caused by it. The lowest LC/EC50 of acute toxicity tests with controlled pH and oxygen concentrations is the 48-h EC50 of 124.2 mg SO32-/L derived for the immobilization of Daphnia magna by ammonium thiosulfate in a guideline test (Springborn Binomics Inc, 1986), and this EC50 is selected as acute ecotoxicity reference value for classification.

The lowest chronic NOEC/EC10 for freshwater fish, invertebrates or algae from a standard test is the 72-h EC10 of 28 mg SO32-/L for the effect of disodium sulfite on the growth rate of Desmodesmus subspicatus (BASF, 1989), and this value was selected as chronic reference value for classification.

Since ammonium hydrogen sulfite is an inorganic substance, biodegradation is not relevant.

For the classification of ammonium hydrogen sulfite, the acute and long-term ecotoxicity reference values of 124.2 and 28 mg sulfite/L are converted to mg (NH4)HSO3/L, resulting in 153.8 mg/L and 34.7 mg/L ammonium hydrogen sulfite, respectively. Based on the acute ecotoxicity reference value and classification criteria of Regulation (EC) No 1272/2008, Table 4.1.0 (a), ammonium hydrogen sulfite does not meet classification criteria of Acute (short-term) aquatic hazard (acute reference value > 1 mg/L). Taking into account the chronic ecotoxicity reference value ammonium hydrogen sulfite does also not meet classification criteria of Chronic (long-term) aquatic hazard (chronic reference value > 1 mg/L) in accordance with Table 4.1.0 (b(i)).