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Ecotoxicological information

Toxicity to microorganisms

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Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Study period:
29 Oct 1992
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
Qualifier:
according to
Guideline:
EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)
Version / remarks:
(1988)
GLP compliance:
not specified
Analytical monitoring:
no
Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: the test item was added directly to the test vessels due to its low water solubility
Test organisms (species):
activated sludge, domestic
Details on inoculum:
- Origin: waste water treatment plant Frankfurt/M-Sindlingen, Germany
- Pretreatment: as cited in study report, sludge was pretreated according to guidelines
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
3 h
Test temperature:
20 ± 2 °C
pH:
7.2 ± 0.2
Nominal and measured concentrations:
Nominal concentrations: 500 and 1000 mg/L
Details on test conditions:
TEST SYSTEM
Inoculum concentration: 1600 mg/L dry weight

Reference substance (positive control):
yes
Remarks:
3,5-Dichlorphenol
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
> 1 000 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate

The test item did not show toxic effects to microorganisms.

EC20 > 1000 mg/L

EC80 > 1000 mg/L

Endpoint:
activated sludge respiration inhibition testing
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Justification for type of information:
Please refer to the category approach justification provided in section 13.
Reason / purpose:
read-across source
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
> 1 000 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Remarks on result:
other:
Remarks:
Source, key, 9004-98-2, Clariant, 1992, 92-0114-O1, act. sludge, 3 h, RL2
Conclusions:
The key effect value for toxicity to microorganisms is an EC50 (3 h) of > 1000 mg/L (nominal, OECD 209).

Description of key information

EC50 (3 h) > 1000 mg/L (nominal)

Key value for chemical safety assessment

Additional information

As there are no data available for alcohol ethoxylate C16, <2.5EO (CAS 9004-95-9), a read across is prepared to a study conducted with alcohol ethoxylate ((Z)-9-Octadecen-1-ol ethoxylated, < 2.5 EO, CAS 9004-98-2). The microorganism toxicity was investigated according to OECD guideline 209 (Clariant, 1992). Domestic, non-adapted sewage sludge was exposed to nominal concentrations of 500 and 1000 mg test item/L for 3 h. No toxic effects on microorganisms were observed up to the highest test concentration.