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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Remarks:
Classification based on calculation rules for mixtures of the CLP Regulation.
Type of information:
calculation (if not (Q)SAR)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
accepted calculation method
Justification for type of information:
Classification based on calculation rules for mixtures of the CLP Regulation, based on constituents approach of the UVCB substance.
There is no experimental study reference.
Data are compiled on 8 major components which represent about 91% of the UVCB.

Data source

Reference
Reference Type:
publication
Title:
ECOSAR v1.11
Author:
EPA United States Environnement Protection Agency
Year:
2012
Bibliographic source:
https://www.epa.gov/tsca-screening-tools/ecological-structure-activity-relationships-ecosar-predictive-model

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
other: ECOSAR
Version / remarks:
1.11
Principles of method if other than guideline:
ECOSAR

Test material

Constituent 1
Reference substance name:
Thuya plicata, ext.
EC Number:
305-105-8
EC Name:
Thuya plicata, ext.
Cas Number:
94334-32-4
Molecular formula:
not relevant as a UVCB substance
IUPAC Name:
Water steam distillation of needles and twigs of Thuya plicata
Test material form:
liquid

Results and discussion

Effect concentrations
Duration:
48 h
Dose descriptor:
LC50
Effect conc.:
1.03 mg/L
Details on results:
The toxicity to daphnia were estimated using the following additivity formulas, as recommended in the Regulation (EC) No 1272/2008 (CLP) section 4.1.3.5.2:
∑ Ci / L(E)C50m = ∑ (Ci / L(E)C50i)
Where,Ci = concentration of component i (weight percentage);
L(E)C50i = LC50 or EC50 for component i, in mg/L; L(E)C50m = L(E)C50 of the part of the mixture with test data.

Applicant's summary and conclusion

Validity criteria fulfilled:
not applicable
Conclusions:
Based on a weight of evidence approach, the toxicity of assessed substance to daphnia during 48 hours can be estimated using adequate toxicity data of major constituents, greater than 1% in the mixture.
These 8 major constituents were considered, representing about 91% of the mixture.
These data are summarized in the above table.
The toxicity to daphnia were estimated using the following additivity formulas, as recommended in the Regulation (EC) No 1272/2008 (CLP) section 4.1.3.5.2:
∑ Ci / L(E)C50m = ∑ (Ci / L(E)C50i)
Where,Ci = concentration of component i (weight percentage);
L(E)C50i = LC50 or EC50 for component i, in mg/L; L(E)C50m = L(E)C50 of the part of the mixture with test data.
Based on data presented above, the EC50 value 48 hours for UVCB substance is calculated at 1.03 mg/L for daphnia.
Executive summary:

With a LC50 daphnia value of 1.03 mg/l and some constituents (terpinene, myrcene, pinene, sabinene and limonene) with logKow > 4, the substance is classified H411 (cat 2) according to table 4.1.0 of regulation 1272/2008 (CLP).