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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
calculation (if not (Q)SAR)
Adequacy of study:
key study
Study period:
2018
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
accepted calculation method

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report Date:
2018

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: REACH guidance on QSARs R.6 (QSPR model adapted specifically from OECD 201 test guideline)
Principles of method if other than guideline:
The growth inhibition of algae was determined using a validated calculation method for the Mechanism of Action (MechoA) in question (MechoA 2.1, i.e. esters whose hydrolysis products are narcotics). This method has previously been validated in an internal publication for acute exposure of non-polar narcosis compounds (Bicherel and Thomas, 2014). The algorithm is based on a QSAR model which has been validated to be compliant with the OECD recommandations for QSAR modeling (OECD, 2004; OECD, 2007). The QSAR model is based on validated data from a training set of 40 chemicals derived from 72-hour test on algae, for which the concentrations of the test item had been determined by chemical analyses over the test period. Further to this the effective loading rate of the WAF is determined by using a series of calculation steps using phase equilibrium thermodynamics and
excluding the non-bioavailable fraction, this approach is based on validated data derived from 72-hour ErL50 tests on algae, for which the concentrations of the test item had been determined by chemical analyses over the test period.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid
Specific details on test material used for the study:
SMILES:
- stearyl octadecanoate: CCCCCCCCCCCCCCCCCCOC(=O)CCCCCCCCCCCCCCCCC
- stearyl hexadecanoate: CCCCCCCCCCCCCCCCCCOC(=O)CCCCCCCCCCCCCCC
- glyceryl monostearate: CCCCCCCCCCCCCCCCCC(=O)OCC(CO)O
- glyceryl distearate: CCCCCCCCCCCCCCCCCC(=O)OCC(COC(=O)CCCCCCCCCCCCCCCCC)O
- glyceryl tristearate: CCCCCCCCCCCCCCCCCC(=O)OCC(COC(=O)CCCCCCCCCCCCCCCCC)OC(=O)CCCCCCCCCCCCCCCCC

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)

Results and discussion

Effect concentrations
Key result
Duration:
72 h
Dose descriptor:
other: ErL50
Conc. based on:
test mat. (dissolved fraction)
Basis for effect:
growth rate
Remarks on result:
other: > water solubility limit
Remarks:
Calculated value

Applicant's summary and conclusion

Validity criteria fulfilled:
not applicable
Conclusions:
According to QSAR model adapted specifically from OECD 201 test guideline, the aquatic algae toxicity (72-h) of the test item is > water solubility limit.