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Ecotoxicological information

Toxicity to microorganisms

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Description of key information

At the test concentration of 1000 mg/l (three replicate flasks), the effect of the test material on the respiration of activated sewage sludge gave a 3-Hour EC50 of greater than 1000 mg/l. The No Observed Effect Concentration (NOEC) after 3 hours exposure was 1000 mg/l. These results show that at conceations in excess of the water solubility value the test material has no significant effect on the respiration rate of activated sewage sludge micro-organisms.

Key value for chemical safety assessment

EC50 for microorganisms:
1 000 mg/L

Additional information

In the key study (Clarke, 2004), the acute toxicity of the test material activated sludge (domestic) was investigated. The study was conducted according to OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test).

This study is presented as the key information as the reliability rating for this study is 2, according to the criteria of Klimisch, 1997, due to no analytical confirmation of dose concentration.

This study was conducted most recently and therefore is considered the most reliable study.

There is also a supporting study available:

- The Ward, Boeri & Paradice, 1994 study was not considered the key study as it was conducted less recently than the above key study. The study was conducted according to the OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test) and GLP.

The reliability rating for this study is 2, according to the criteria of Klimisch, 1997, due to no analytical confirmation of dose concentration.

The test substance inhibited respiration by the activated sludge only slightly in the tested range of concentrations. The 3 hour EC50 for activated sludge exposed to the test material was greater than 1,000 mg/L, the highest tested concentration.