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Ecotoxicological information

Toxicity to microorganisms

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Description of key information

Ecotoxicity of the test substance was evaluated using the activated sludge, respiration inhibition test. The substance, up to the concentration of 1,000 ppm, did not show significant toxicity toward the microbial population. At higher concentration, slight inhibition of microbial respiration was observed and the EC50 was estimated to be higher than 10,000 ppm. 

Key value for chemical safety assessment

EC50 for microorganisms:
10 000 mg/L
EC10 or NOEC for microorganisms:
1 000 mg/L

Additional information

In the key study, 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).

The reliability rating for this study is 1, however this is being used as read across from a structurally similar substance (Phenol, dodecyl-, sulfurized, calcium salts. CAS No. 220794 -90 -1) as there was no available data to fulfil this endpoint for the test material and so the reliability rating will be reduced to 2, according to the criteria of Klimisch, 1997.

There is also a supporting study available:

- The Goodrich, M & Teer, L., 1994 study (Woodward-Clyde Consultants, report number: 109318) was not considered the key study as it was conducted less recently than the above key study and only a summary was available. The study was conducted according to the OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test) and GLP. The study was considered to have a reliability rating of 4, according to the criteria of Klimisch, 1997 as only a summary of the study is available, therfore there is limited information on materials and methods.

The respiration rates of the sludge-associated microbes exposed to the five concentrations of the test material were 39.7, 43.5, 37.7, 44.4 and 33.1 mg O2/L hr respectively. The EC50 was calculated to be greater than 10,000 mg/L.

(Read across to a supporting substance (Phenol, dodecyl-, sulfurized, calcium salts. CAS No. 220794 -90 -1).