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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
(Q)SAR
Adequacy of study:
key study
Study period:
30th March, 2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Data source

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

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
other: REACH Guidance on QSARs R.6 (QSAR model adapted specifically from test guideline: OECD 202, EU C.2)
Principles of method if other than guideline:
Purpose:
The purpose of this QSAR model is to accurately predict the acute toxicity to daphnid as would be expected in a laboratory experiment following OECD Guideline 202 and EC method C.2 for specific, named modes of action to provide a value that can effectively replace a 48-hour EC50 value from an experimental study. The regression based method used to achieve this has been fully validated following the OECD (2004) recommendations (refer to the QMRF report with JRC/KREATiS QMRF identifier: Q19-46-51-448 for further details).

Species:
Results from the following species were used in the regression:
Daphnia magna, Daphnia pulex
No difference in relationship between solubility and ecotoxicity between invertebrate (or indeed other) aquatic species is expected. Any observed differences may be attributed to lifestyle related parameters (e.g. shell closing in molluscs) and relative duration of study versus bodysize rather than to a specific toxic mechanism causing species differences.

Test duration:
Results from a test duration of 48 hours only were used for daphnid and ceriodaphnid species.

Temperature:
The temperatures varied from approximately 20 to 23 °C depending on the species used to construct the algorithm. This small difference is not expected to contribute to the variability of the EC50 values found in experimental data.

Test type:
Preferentially results from semi-static studies were used. However, substances tested using a static design were accepted (preferably accompanied by analytical measurements over the study period). For suspected volatile substances only tests performed in closed vessels were accepted unless accompanying analytical monitoring proved such a design was not necessary.

pH:
Test results were taken from studies with measured pHs between 6 - 9.
GLP compliance:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
Batilol
EC Number:
208-874-7
EC Name:
Batilol
Cas Number:
544-62-7
Molecular formula:
C21H44O3
IUPAC Name:
3-(octadecyloxy)propane-1,2-diol
Test material form:
solid: particulate/powder
Specific details on test material used for the study:
Smiles: CCCCCCCCCCCCCCCCCCOCC(O)CO
Melting point (if solid) 66.8 °C
log KOW log KOW = 7.8
Water Solubility 4.26E-03 mg/L

Test organisms

Test organisms (species):
Daphnia magna

Results and discussion

Effect concentrations
Key result
Duration:
48 h
Dose descriptor:
EC50
Nominal / measured:
nominal
Conc. based on:
test mat.
Remarks on result:
not determinable
Remarks:
the EC50 was > to the solubility limit

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Executive summary:

The immobility of the daphnids was determined using a validated QSAR model for the Mechanism of Action (MechoA) in question (MechoA 1.1, i.e. non-polar narcosis) (4). The QSAR model is based on validated data for a training set of 58 chemicals derived from 48-hour test on daphnids, for which the concentrations of the test item had been determined by chemical analyses over the test period.

The result below is the acute toxicity value anticipated during a 48-hour EC50 study on daphnids based on measured concentrations. The 48-hour EC50 is calculated as follows:

48h EC50 > solubility limit (0.00426mg/l)