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Ecotoxicological information

Toxicity to microorganisms

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Reference
Endpoint:
activated sludge respiration inhibition testing
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Justification for type of information:
C12 LAS; Linear Alkylbenzene Sulfonate (LAS)) is a very close analogue of Calcium dodecylbenzenesulfonate (CAS No 26264-06-2, EC Number; 247-557-8) ) and read-across is valid.
Reason / purpose for cross-reference:
read-across source
Qualifier:
according to guideline
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
Principles of method if other than guideline:
The purpose of the study was to determine the toxicity of five purehomologues of LAS to the activated sludge of a treatment plant basically operating on domestic sewage. A contact time of 3 hours instead of 15 minutes was chosen to better simulate the real residence time used in wastewater treatment plants (4-6 hours).
GLP compliance:
not specified
Analytical monitoring:
not specified
Vehicle:
not specified
Test organisms (species):
activated sludge
Test type:
other: aquatic
Limit test:
no
Total exposure duration:
3 h
Details on test conditions:
Activated sludges:The activated sludge from the aeration pond of the sewage treatment plant of Estepona. This sludge has a carbon content of 40% and moisture level of 82%.
Reference substance (positive control):
yes
Remarks:
3,5-dichlorophenol
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
>= 500 - <= 723 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Details on results:
Acute toxicity to Microorganism (activated sludge): 3hr-EC50 is 500-723 mg/L (nominal).
Results with reference substance (positive control):
The 3-hour EC50 range for the reference substance (3,5-dichlorophenol) ranged from 20- 30 mg/L, within the valid range of 5-30 mg/L
Validity criteria fulfilled:
yes
Conclusions:
Acute toxicity to Microorganism (activated sludge): 3hr-EC50 is 500-723 mg/L (nominal).

Description of key information

Acute toxicity to Microorganism (activated sludge): 3hr-EC50 is 500-723 mg/L (nominal).

Key value for chemical safety assessment

EC50 for microorganisms:
500 mg/L
EC10 or NOEC for microorganisms:
100 mg/L

Additional information

Acute toxicity to Microorganism (activated sludge): 3hr-EC50 is 500-723 mg/L (nominal).

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