Fatty acids, C5-10 (linear and branched), mixed esters with pentaerythritol

Toxicity to soil macroorganisms except arthropods

Description of key information

NOEC (56 d) ≥ 1000 mg/kg dw for Eisenia fetida (OECD 222)

Additional information

Since no studies investigating the toxicity to soil macroorganisms of fatty acids, C5-10 (linear and branched), tetraesters with pentaerythritol (CAS 68424-31-7) are available for this endpoint, in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5 a read across to five structurally related category members decanoic acid, mixed esters with heptanoic acid, octanoic acid, pentaerythritol and valeric acid(CAS 71010-76-9), a TMP triester, 2-ethyl-2-[[(1-oxoheptyl)oxy]methyl]propane-1,3-diyl bisheptanoate (CAS 78-16-0), fatty acids, C16-18 and C18-unsatd., tetraesters with pentaerythritol (CAS 68604-44-4), 2,2-bis(hydroxymethyl)-1,3-propanediyl dioleate (CAS 25151-96-6), and fatty acids, C16-18 and C18-unsatd., esters with pentaerythritol (CAS 85711-45-1) was conducted. The target category member as well as the first two read-across substance both exhibit shorter fatty acid chain lengths (≤ C10), however only one contains pentaerythritol and is a tetra-ester. The second read across substance is a triester with TMP. The remaining three read-across substances cover the other end of the PE group with longer fatty acid chains (≥ C16). This read-across is justified in detail in the overall summary (IUCLID chapter 6.3) and within the category justification in IUCLID Section 13. In this case of read-across, the best suited (highest degree of structural similarity, nearest physico-chemical properties) read-across substance was used for the assessment. Nevertheless, as it can be seen in the data matrix of the category justification in section 13 and the overall summary, all reliable data in the category support the hazard assessment of each category member by showing a consistent pattern of results.

The short term toxicity of decanoic acid, mixed esters with heptanoic acid, octanoic acid, pentaerythritol and valeric acid (CAS 71010-76-9) was investigated according to OECD guideline 207 and under GLP (Kelley, 2013). Using artificial soil that was mixed with the test substance. Earthworms of the species Eisenia fetida were exposed to the test substance for 14 days and then removed from the test substrate. The survival rate and growth (body weight) of the specimen were determined. Neither mortality or a decrease in body weight of the adult earthworms was not observed. Thus a NOEC 1000 mg/kg soil based on mortality was reported. A NOEC ≥ 1000 mg/kg soil based on the reproduction rate was determined.

In the second read across study with a shorter chained poloyl ester the long-term toxicity of 2-ethyl-2-[[(1-oxoheptyl)oxy]methyl]propane-1,3-diyl bisheptanoate (CAS 78-16-0) to earthworms was investigated according to OECD guideline 222 and under GLP (Eisner, 2013). The test was conducted with artificial soil that was mixed with the test substance. Earthworms of the species Eisenia fetida were exposed to the test substance for 28 days and then removed from the test substrate. The survival rate and growth (body weight) of the specimen were determined. After another 28 days the hatched juveniles were collected from the test substrate and the reproduction rate was recorded. Mortality or a decrease in body weight of the adult earthworms was not observed. Thus a NOEC 1000 mg/kg soil based on mortality was reported. A NOEC ≥ 1000 mg/kg soil based on the reproduction rate was determined.

In the third read across study the chronic toxicity of fatty acids, C16-18 and C18-unsatd., tetraesters with pentaerythritol (CAS 68604-44-4) to earthworms was conducted according to OECD 222 under GLP conditions (Amsel, 2013). Eisenia andrei was exposed to a test concentration of 1000 mg/kg dw in artificial soil for 56 days. Mortality and reproduction were recorded at the end of the study. No effects were observed resulting in a NOEC (28 d) of ≥ 1000 mg/kg dw based on mortality and a NOEC (56 d) of ≥ 1000 mg/kg dw based on reproduction. Due to these results it can be concluded that fatty acids, C16-18 and C18-unsatd., tetraesters with pentaerythritol (CAS 68604-44-4) will not exhibit effects on soil macroorganisms.

A further chronic test with the read-across substance2,2-bis(hydroxymethyl)-1,3-propanediyl dioleate (CAS 25151-96-6) was conducted according to OECD 222 under GLP conditions (Simon, 2013). Eisenia fetida was exposed to the test concentrations 500 and 1000 mg/kg dw in artificial soil for 56 days. Mortality and reproduction were recorded at the end of the study. No effects were observed resulting in a NOEC (28 d) of ≥ 1000 mg/kg dw based on mortality and a NOEC (56 d) of ≥ 1000 mg/kg dw based on reproduction.

Finally once more it was shown that the polyol esters do not pose a risk to terrestrial organisms in an OECD 222 test investigating the chronic toxicity of fatty acids, C16-18 and C18-unsatd., esters with pentaerythritol, CAS 85711-45-1 to Eisenia fetida at a test concentration of 1000 mg/kg dw in artificial soil for 56 days (Amsel, 2013). No effects were observed resulting in a NOEC (28 d) of ≥ 1000 mg/kg dw based on mortality and a NOEC (56 d) of ≥ 1000 mg/kg dw based on reproduction.

Based on the results from a structurally related read-across substance (in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5) which is characterized by an equal ecotoxicological profile, it can be concluded that fatty acids, C5-10 (linear and branched), tetraesters with pentaerythritol (CAS 68424-31-7) will not exhibit effects on soil macroorganisms.