Reaction product of mixed triesters of heptanoic acid (n-C7), nonanoic acid (n-C9) and trimethylolpropane (i-C7)

Endpoint summary

Additional information

A detailed justification for grouping of substances is provided in section 5 of IUCLID.

The following table illustrates the read across approach taken within the PE ester group of the polyol esters category. In order to get a good overview, only the ecotoxicological parameters for the aquatic compartment of the relevant substances used as part of a read across approach for the PE esters of the category have been listed in the table below. The complete data matrix of all polyol esters for aquatic toxicity is however detailed within the category justification attached in IUCLID section 13 of this dossier.

In accordance with Regulation (EC) No. 1907/2006, Annex XI, 1.5, grouping and read-across, the polyol esters, which of course includes the polyol PE group, are not considered to be harmful to aquatic organisms based on the results from short-term studies with fish, aquatic invertebrates and algae and long-term results on toxicity to aquatic invertebrates. Moreover, all polyol PE esters within the polyol esters category are structurally similar and read-across was performed to the structurally most similar polyol esters category member(s). The available studies cover the variability of the PE esters group with different alcohol and fatty acid chain lengths. The data gaps within the PE esters group were filled by interpolation since the category members are characterized by a similar pattern in the ecotoxicological toxicity profile. No trend in toxicity was observed since no effects were recorded up to the limit of water solubility. There is no convincing evidence that any one of the category members might lie out of the overall profile of this category.

Short-term toxicity studies with freshwater species for numerous members of the category are available for all three trophic levels (algae, aquatic invertebrates and fish). Acute toxicity studies to fish according to internationally accepted guidelines are available for eleven PE esters group members: fatty acids, C16-18 and C18-unsatd., esters with pentaerythritol (CAS 85711-45-1), 2,2-bis(hydroxymethyl) -1,3-propanediyl dioleate (CAS 25151-96-6), fatty acids, C5-9 tetraesters with pentaerythritol (CAS 67762-53-2), decanoic acid, mixed esters with heptanoic acid, octanoic acid, pentaerythritol and valeric acid (CAS 71010-76-9), decanoic acid, mixed esters with octanoic acid and pentaerythritol (CAS 68441-68-9), pentaerytritol tetraoleate (CAS 19321-40-5), pentaerythritol tetraisostearate (CAS 62125-22-8), fatty acids, lanolin, esters with pentaerythritol (CAS 68440-09-5), fatty acids, C8-10 mixed esters with dipenaterythritol, isooctanoic acid, pentaerythritol and tripentaerythritol (CAS 189200-42-8) and fatty acids, C8-10 (even numbered), di-and triesters with propylidynetrimethanol (CAS 11138-60-6) and pentaerythritol tetraesters of n-decanoic, n-heptanoic, n-octanoic and n-valeric acids(CAS 68424-31-7). All test results led to the same conclusion: No effects were observed up to the limit of water solubility, for any of the above mentioned test substances.

Furthermore, this lack of toxicity was further confirmed in eight short-term toxicity studies with aquatic invertebrates for the PE esters group; fatty acids, C5-9 tetraesters with pentaerythritol (CAS 67762-53-2), decanoic acid, mixed esters with heptanoic acid, octanoic acid, pentaerythritol and valeric acid (CAS 71010-76-9), pentaerytritol tetraoleate (CAS 19321-40-5), fatty acids, C16-18 and C18-unsaturated, tetraesters with pentaerythritol (CAS 68604-44-4), 2,2-bis[[(1-oxoisooctadecyl) oxy]methyl]-1,3-propanediyl bis(isooctadecanoate) (CAS 62125-22-8), fatty acids, lanolin, esters with pentaerythritol (CAS 68440-09-5), fatty acids, C8-10 mixed esters with dipenaterythritol, isooctanoic acid, pentaerythritol and tripentaerythritol (CAS 189200-42-8) and fatty acids, C8-10 (even numbered), di-and triesters with propylidynetrimethanol (CAS 11138-60-6). No toxicity was observed up to the limit of water solubility in the available studies. The available studies cover the variability within the group with regards to different alcohol components and representative fatty acid chain lengths. Thus, the data gaps can be confidently covered by interpolation.

Reliable standard guideline studies investigating the toxicity to aquatic algae are available for the five following substances: fatty acids, C16-18, esters with pentaerythritol (CAS 85116-93-4), fatty acids, C16-18 and C18-unsaturated, tetraesters with pentaerythritol (CAS 68604-44-4), 2,2-bis[[(1-oxoisooctadecyl) oxy]methyl]-1,3-propanediyl bis(isooctadecanoate) (CAS 62125-22-8), fatty acids, C8-10 mixed esters with dipenaterythritol, isooctanoic acid, pentaerythritol and tripentaerythritol (CAS 189200-42-8) and fatty acids, C8-10 (even numbered), di-and triesters with propylidynetrimethanol (CAS 11138-60-6). No toxicity was observed up to the limit of water solubility in the available studies. The studies adequately cover the variability of the PE ester group with regards to the different alcohol components and fatty acid chain lengths at both the lower and upper end of the category. Thus, the data gaps can be again confidently predicted by interpolation.

Three long-term studies with Daphnia magna are available for fatty acids, C16-18 and C18-unsatd., esters with pentaerythritol (CAS 85711-45-1), decanoic acid, mixed esters with heptanoic acid, octanoic acid, pentaerythritol and valeric acid (CAS 71010-76-9) and fatty acids, C8-10 (even numbered), di-and triesters with propylidynetrimethanol (CAS 11138-60-6). The study with fatty acids, C16-18 and C18-unsatd., esters with pentaerythritol (CAS 85711-45-1) was performed as a limit test according to OECD 211 and GLP (Schlechtriem, 2013). Exposure of Daphnia magna to a 1 mg/L WAF of the test substance had no statistically significant effect on reproduction. Therefore the NOEL is determined to be ≥ 1 mg/L. The GLP study with decanoic acid, mixed esters with heptanoic acid, octanoic acid, pentaerythritol and valeric acid (CAS 71010-76-9) was conducted under semi-static conditions according to OECD 211 using Daphnia magna as test organism (Letinski & Bragin, 2012). A nominal test concentration of 135 mg/L was applied in a limit test. No significant effect on reproduction was observed in the treatment throughout the test period of 21 d. Hence, the 21 d-NOELR is determined to be > 135 mg/L. The third study with fatty acids, C8-10 (even numbered), di-and triesters with propylidynetrimethanol (CAS 11138-60-6) was performed under semi-static conditions under GLP similar to OECD 211(Low, 1996). Daphnia magna was exposed to five nominal concentrations up to 2570 mg/L. No effects were observed up to the highest test concentration resulting in a NOELR of > 2570 mg/L based on reproduction and immobilization. It can be concluded that the latter two substances can be seen as a worst case read-across approach based on the smaller fatty acid chain lengths (C5-C10) which probably exhibits a higher water solubility since the hydrocarbon chain lengths of the fatty acid is directly correlated with the water solubility (Lide, 2005).

Although chronic toxicity data is available for members within the polyol esters category in accordance to Regulation (EC) No 1907/2006, Annex IX 9.1 Aquatic toxicity, further tests on long term toxicity to invertebrates for the PE esters tetra-esterification products of 2,2-bis[[(1-oxopentyl) oxy]methyl]propane-1,3-diyl divalerate (CAS 15834-04-5), tetraesters from esterification of pentaerythritol with pentanoic, heptanoic and isononanoic acids (CAS 68424-30-6), tetra-esterification products of C5, C7, C8, C10 fatty acids with pentraerythritol (CAS 68424-31-7) and fatty acids, C8, C10, C12, C14, C16 esters with pentaerythritol, reaction product of coconut oil fatty acids, C8-10 fatty acid mix and pentaerythritol (CAS 85049-33-8) are proposed to extend the overall dataset. CAS 15834-04-5 has the shortest chain length (C5) of PE esters, it is a mono-constituent and often is a constituent with many of the other polyol esters. Due to its smaller molecular size it is expected to have the highest bioavailability. CAS 68424-30-6 was chosen on the basis of its isononanoic acid content to evaluate possible adverse effects. CAS 68424-31-7 (tetra-esterification products of C5, C7, C8, C10 fatty acids with pentraerythritol) is a highly complex UVCB, with varying chain lengths and combinations of structures. CAS 85049-33-8 was selected in order to confirm that no chronic toxicity to aquatic organisms occurs for the polyol esters with medium chain length of the category, C8-C16 (even numbered). As soon as this data are available the hazard and chemical safety assessment according to Annex I of Regulation (EC) No. 1907/2006 will be updated.

In summary, based on these results from acute tests with fish, daphnia and algae as well as chronic tests with aquatic invertebrates, there is no convincing evidence that the other polyol esters category members lie out of the overall toxicity profile.

Toxicity to microorganisms was investigated in five GLP studies within the polyol PE group for decanoic acid, mixed esters with heptanoic acid, octanoic acid, pentaerythritol and valeric acid (CAS 71010-76-9), pentaerytritol tetraoleate (CAS 19321-40-5), pentaerythritol tetraisostearate (CAS 62125-22-8), fatty acids, C8-10 (even numbered), di-and triesters with propylidynetrimethanol (CAS 11138-60-6) and pentaerythritol tetraesters of n-decanoic, n-heptanoic, n-octanoic and n-valeric acids (CAS 68424-31-7). Additionally, toxicity controls of biodegradation studies for four substances (pentaerytritol tetraoleate (CAS 19321-40-5, pentaerythritol tetraisostearate (CAS 62125-22-8), fatty acids, lanolin, esters with pentaerythritol (CAS 68440-09-5) and fatty acids, C16-18 and C18-unsaturated, esters with pentaerythritol (CAS 85711-45-1)) were taken into consideration. No effects on O2-consumption and no effects on respiration of activated sludge microorganisms were observed. In combination with results from all other category members, it can be concluded that no effects on the STP microorganism community and the subsequent degradation process in sewage treatment plants is anticipated for the polyol esters category.

In conclusion, in the available studies for the PE esters no effects on aquatic organisms were observed up to the water solubility in any of the three trophic levels (fish, aquatic invertebrates, algae), either in the short-term toxicity tests or in the long-term test with daphnids. The polyol esters category is a robust category with a large amount of reliable data which allows a conclusive overview about the overall ecotoxicological profile of all category members. In each case of read-across, the best suited read-across was chosen. Nevertheless, as it can be seen in the data matrix of the category justification in IUCLID Section 13, all reliable data in the category support the hazard assessment of each category member by showing a consistent pattern of results.