Acetonitrile in freshwater and marine water

Toxicant default guideline values for protecting aquatic ecosystems

October 2000

Extracted from Section 8.3.7 ‘Detailed descriptions of chemicals' of the ANZECC & ARMCANZ (2000) guidelines.

The default guideline values (previously known as ‘trigger values’) and associated information in this technical brief should be used in accordance with the detailed guidance provided in the Australian and New Zealand Guidelines for Fresh and Marine Water Quality.

Description of chemical

Acetonitrile (CAS 75-05-8) is mostly used as a solvent in hydrocarbon extraction, in textile dyes, in extraction of fatty acids from animal and vegetable oils and as a basis for chemical synthesis and in pharmaceutical manufacture (Nielsen & Howe 1995). Its formula is C₂H₃N, and molecular weight is 41.05. It is miscible with water and has a very low Log K_ow.

Aquatic toxicology

The only data available are for a freshwater crustacean: Daphnia magna 48-hour LC50, 3600 mg/L; 9-day chronic NOEC for mortality of 640 mg/L and for reproduction of 160 mg/L. Nielsen & Howe (1995) reported acute toxicities to fish (four species) >1000 mg/L.

Guideline

A freshwater low reliability trigger value of 160 µg/L was calculated for acetonitrile using an assessment factor (AF) of 1000. In the absence of marine data, this was adopted as a marine low reliability trigger value. These figures should only be used as indicative interim working levels.

References

ANZECC & ARMCANZ 2000. Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Environment and Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand, Canberra.

Nielsen IR & Howe PD 1995. Environmental hazard assessment: Acetonitrile. TSD 23, Toxic Substances Division, Department of the Environment, Garston, UK.