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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Reference
Endpoint:
toxicity to aquatic algae and cyanobacteria
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 chapter 13 for the read-across justification.
Reason / purpose for cross-reference:
read-across source
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
8.5 mg/L
Basis for effect:
growth rate
Remarks on result:
other: test result from read-across source CAS 90170-43-7 (Hamilton Garrod Ltd., 1995).
Key result
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
6.69 mg/L
Basis for effect:
growth rate
Remarks on result:
other: test result from read-across source CAS 90170-43-7 (Hamilton Garrod Ltd., 1995).

Description of key information

A valid read-across algae study in green algae according to OECD 201 is available.  

ErC50 = 8.5 mg/L (Chlorella vulgaris)  

ErC10 = 6.69 mg/L (Chlorella vulgaris)

Key value for chemical safety assessment

EC50 for freshwater algae:
8.5 mg/L
EC10 or NOEC for freshwater algae:
6.69 mg/L

Additional information

Since no data on toxicity to aquatic algae and cyanobacteria of the test substance is available, the assessment is based on a study of the close structural analogue β-Alanine, N-(2-carboxyethyl)-, N-coco alkyl derivs., disodium salts (CAS 90170-43-7).

The toxicity towards freshwater algae was determined in a study according to OECD TG 201 and in compliance with GLP criteria (Hamilton Garrod Ltd., 1995). In this study, exponentially growing freshwater alga (Chlorella vulgaris) were exposed to nominal test substance concentrations of 0 (control), 6, 13, 25, 50 and 100 mg/L for 72 hours under static conditions, corresponding to concentrations of 0 (control), 1.8, 3.9, 7.5, 15 and 30 mg a.i./L. No analytical confirmation of the test substance was performed. The cell density in each replicate control and test concentration flask was measured at 24, 48 and 72 hours. Based on these results, inhibition of growth rate was calculated. After 72 hours exposure, inhibition of green algae was observed from a test concentration of approximately 3.9 mg a.i./L based on biomass and 7.5 mg a.i./L for growth rate and increased in a dose-dependent manner. After an exposure period of 48 hours, inhibition was generally higher at the lower test concentrations, than after 72 hours. The 72-h EC50 values for growth rate and yield/biomass were reported to be 9.3 mg a.i./L and 5.4 mg a.i./L, respectively. As no EC10 was originally derived from the data, the data was re-evaluated. From the re-evaluated data, the following new effect values were calculated: the 72-h ErC50 was determined to be 8.5 mg a.i./L, whereas the 72-h ErC10 was determined to be 6.69 mg a.i./L.