Fatty acids, C16-18, stearyl esters

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

Refer to the analogue approach justification provided in IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Remarks on result:

not determinable because of methodological limitations

Remarks:

No suitable analytical method could be established to conduct this study properly. Source: RA-A, CAS 93803-87-3, Notox, 1998

Conclusions:

A long-term study is technically not feasible due to substance properties (i.e. poor water solubility and high potential for adsorption), based on an experimental study with a structurally and chemically closely related source substance (OECD 202); read-across

Description of key information

A study according to OECD 211 is technically not feasible due to substance characteristics; read-across

Additional information

There is no study available, in which the long-term toxicity of the target substanceFatty acids, C16-18, stearyl esters (CAS 85536-04-5) to aquatic invertebrates was assessed. Therefore, read-across to the structurally related source substance 2-octyldodecyl isooctadecanoate (CAS 93803-87-3) was conducted in accordance with Regulation (EC) No. 1907/2006 Annex XI, 1.5. The source substance is characterized by similar fatty acid chain lengths and alcohol components as the target substance and is therefore considered a suitable representative for the assessment of the long-term toxicity of the target substance to aquatic invertebrates. A detailed justification of the analogue approach is provided in IUCLID section 13.

No experimental study is available for the long-term toxicity of the source substance 2-octyldodecyl isooctadecanoate (CAS 93803-87-3) to aquatic invertebrates. However, a statement from a laboratory is available explaining that a long-term study is technically not feasible due to the properties of the test item.

The testing of the acute toxicity of poorly soluble substances to Daphnia magna is commonly performed by exposing the organisms to Water Accommodated Fractions. Owing to the fact that the test item is a liquid with water solubility below the detection limit of < 0.05 mg/L and a log Kow of > 7.0, it was not possible to prepare test solutions for a 21-day reproduction test with D. magna. Furthermore, based on the high hydrophobicity, there is no analytical method sensitive enough to detect concentrations of the test item in water samples. As a result, it is not possible to obtain any analytical data to meet the acceptability criterion for stable exposure concentrations (i.e. within ± 20% of nominal) throughout the total test period. In addition, it is considered highly unlikely that bioavailable concentrations of the test item will ever occur in the water phase, i.e. that concentrations high enough to induce any acute or chronic effects in aquatic organisms are every attained due to the particular substance characteristics. Therefore, no chronic test with aquatic invertebrates was conducted for the source substance 2-octyldodecyl isooctadecanoate (CAS 93803-87-3).

 

Based on the high degree of structural and chemical similarity between the target and the selected source substance, testing of the long-term toxicity of the target substance to aquatic invertebrates is expected to face similar technical challenges. Therefore, it is concluded that a study according to OECD 211 is technically not feasible due to the characteristics of the target substanceFatty acids, C16-18, stearyl esters (CAS 85536-04-5).