Methyl 12-hydroxyoctadecanoate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

20 April 2010 to 23 April 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The analogue approach is used for the hazard assessment of toxicological, eco-toxicological and environmental fate endpoints for the registration of 12-hydroxstearate methyl ester (CAS 141-23-1). The hypothesis is that data can be read-across between this ester and its structural analogues, based on structural similarity and which cause the same type of effect(s) in physical and biological systems (Scenario 2 of the Read-Across Assessment Framework (RAAF, ECHA, 2015). The primary fatty acid ester in this read-across for environmental fate and ecotoxicological endpoints is methyl myristate (C14), as this substance is well-studied with high-quality experimental data. Supplemental analogues are used which contribute understanding of the effects of other structural features not contained in the two primary analogues.

The substance and its analogue have not been shown to exhibit toxicity to aquatic organisms (based on short-term studies on all three trophic levels) or be inhibitory to degradative micro-organisms. Both the substance and its analogue have been shown to be readily biodegradable and are not expected to be highly persistent in the environment. And, although both substances exhibit low solubility and a high octanol-water partition coefficient, neither substance is expected to bioaccumulate and pose a concern for food chain exposures, due to the metabolism by carboxylesterases and lipases in vertebrate and invertebrate systems.

There are no GHS classifications for 12-hydroxstearate methyl ester for endpoints which are reliant on read-across. There is a high degree of confidence that hazards for these endpoints are not underestimated, based on a strong weight of evidence from multiple data sources.

Read-across data, all evaluated as reliable according to Klimisch scores of 1 or 2, were used to estimate the toxicity of the registered substance for fulfilling the data requirements of the REACH registration and classifying potential hazards. This read-across approach is adequate for the purposes of risk assessment and classification and labeling.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

2004

Deviations:

yes

Remarks:

Test vessels with a volume of 60 ml (filled with 50 ml) were used in the final test. Size and volume of the test vessels are not critical as long as a minimum volume of 2 ml per organism is available; did not adversely affect study integrity.

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

2008

Deviations:

yes

Remarks:

Test vessels with a volume of 60 ml (filled with 50 ml) were used in the final test. Size and volume of the test vessels are not critical as long as a minimum volume of 2 ml per organism is available; did not adversely affect study integrity.

Qualifier:

according to guideline

Guideline:

ISO 6341 (Water quality - Determination of the Inhibition of the Mobility of Daphnia magna Straus (Cladocera, Crustacea))

Version / remarks:

1996

Deviations:

yes

Remarks:

Test vessels with a volume of 60 ml (filled with 50 ml) were used in the final test. Size and volume of the test vessels are not critical as long as a minimum volume of 2 ml per organism is available; did not adversely affect study integrity.

GLP compliance:

yes

Test organisms (species):

Daphnia magna

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other:

Remarks:

48 hr EC50 exceeded 100 mg/L for a glass fibre solution prepared using a WSF with a loading rate of 100 mg/L corresponding to an initial measured concentration of 0.02 mg/L or lower (i.e., the maximum solubility in test medium).

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

100 mol/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Conclusions:

The test substance did not induce acute immobilisation of Daphnia magna exposed to a Water Soluble Fraction (WSF) solution prepared using a glass fibre filtered solution with a loading rate of 100 mg/L and dilutions containing 10%, 18%, 32% and 56% of the filtrate. The 48-h NOEC was 100 mg/L, the 48-h LOEC was > 100 mg/L and the 48-hr EC50 was > 100 mg/L.

Description of key information

The key study was a semi-static acute invertebrate toxicity test on the effects of the substance on the freshwater invertebrate Daphnia magna following OECD Guideline 202.  Acute immobilisation of Daphnia magna was not observed after 48 h exposure to the substance at a series of test concentrations. The initial test solution was prepared as the Water Soluble Fraction (WSF) at a loading rate of 100 mg/L using a glass fibre filter; subsequent dilutions established test solutions containing 10%, 18%, 32% and 56% of the initial WSF solution. The 48-h NOELR was 100 mg/L, the 48-h LOELR was > 100 mg/L and the 48-hr EC50 was > 100 mg/L.