Benzidine 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

Benzidine is used in the manufacture of dyes and as an analytical reagent. It can enter the aquatic environment mainly through discharges from dye plants (USEPA 1980j). Few data are available regarding the fate and toxicity of benzidine in aquatic systems. Acute toxicity to freshwater animals can occur at concentrations as low as 2500 µg/L (USEPA 1986). No data were available concerning the toxicity of benzidine to marine organisms (USEPA 1986). Benzidine has a log Kow​ of 1.34.


There were insufficient data for guideline derivation for benzidine. Users may apply a factor of 1000 to the lowest USEPA figure to derive an environmental concern level (ECL) (see Section of the ANZECC & ARMCANZ 2000 guidelines) of 2.5 µg/L as an indicative interim working level.


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.

USEPA 1980j. Ambient water quality criteria for benzidine. Criteria and Standards Division, US Environmental Protection Agency, Washington DC.

USEPA 1986. Quality criteria for water. US Department of Commerce, National Technical Information Service, US Environmental Protection Agency, Springfield, Virginia. PB87-226759, EPA 440/5 86-001.