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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:
(Q)SAR
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Calculation of the LC50 of Ceraphyl 41 based on the individual QSAR data for the C12-C15 lactates.
Justification for type of information:
QSAR prediction: migrated from IUCLID 5.6
Reason / purpose:
(Q)SAR model reporting (QMRF)
Principles of method if other than guideline:
Calculation of the LC50 of a mixture based on individual LC50 values for the components assuming a similar mode of action.
GLP compliance:
no
Test organisms (species):
other: Fresh water algae
Water media type:
freshwater
Total exposure duration:
96 h
Key result
Duration:
96 h
Dose descriptor:
EC50
Effect conc.:
0.1 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Remarks:
Ceraphyl 41
Basis for effect:
growth rate
Key result
Duration:
4 d
Dose descriptor:
other: ChV
Effect conc.:
0.091 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate

Description of key information

Value calculated based on ECOSAR estimated individual ErC50 values for the C12, C14 and C16 lactates being the main constituents of Propanoic acid, 2-hydroxy, C12-C16 (even numbered) alkyl esters.

Key value for chemical safety assessment

EC50 for freshwater algae:
0.097 mg/L
EC10 or NOEC for freshwater algae:
0.091 mg/L

Additional information

Estimation of the EC50 ofPropanoic acid, 2-hydroxy, C12-C16 (even numbered) alkyl estersfor growth rate of fresh-water algea:

Assumption: Similar Mode of Action for C12-15 lactates

f=fraction of chemical in mixture

Calculation:

f EC50 1/EC50 f/EC50
C12-lactate 0.6 0.378 2.646 1.5873
C14-lactate 0.3 0.086 11.628 3.4884
C16-lactate 0.1 0.019 52.632 5.2632
Σf/EC50 10.339
EC50 - Propanoic acid, 2-hydroxy, C12-C16 (even numbered) alkyl esters 0.097 mg/L

Estimation of the chronic value of Propanoic acid, 2-hydroxy, C12-C16 (even numbered) alkyl esters for fresh water algae:

Calculated based on QSAR values for Ester Toxicity:

Lactate ChV 1/ChV f f/ChV
Dodecyl lactate 0.235 4.255 0.60 2.5532
Tetradecyllactate 0.074 11.51 0.30 4.0541
Hexadecyllactate 0.023 43.47 0.10 4.3478
Σf/ChV 10.96

ChV ofPropanoic acid, 2-hydroxy, C12-C16 (even numbered) alkyl esters 

0.091

f= estimated average fraction of chemical in mixtures

Based on the analytical results of the 96h algal test with octyl lactate in the referred study, alkyl lactates with C-chains of 8 carbons or more, degrade rapidly due to hydrolysis and bacterial activity.