Heptanoic acid, mixed esters with pentaerythritol and valeric acid

Short-term toxicity to fish

Description of key information

No toxic effects to fish up to the limit of water solubility.

Additional information

In accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5 a read across to four structurally related category members pentaerythritol tetraesters of n-decanoic, n-heptanoic, n-octanoic and n-valeric acids (CAS 68424-31-7), decanoic acid, mixed esters with heptanoic acid, octanoic acid, pentaerythritol and valeric acid (CAS 71010-76-9), fatty acids, C5-9 tetraesters with pentaerythritol (CAS 67762-53-2) and fatty acids, C8-10 mixed esters with dipentaerythritol, isooctanoic acid, pentaerythritol and tripentaerythritol (CAS 189200-42-8) in order to fulfil the data requirements according to Annex VII-IX. This read-across is justified in detail in the overall summary (IUCLID chapter 6.1) 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 substances were used for the assessment. The first three read-across substances have the same alcohol component, i.e. pentaerythritol (the fourth additionally exhibits dipentaerythritol), and are tetra-esters with a fatty acid chain length within the range of C5 – C10 are comparable to the target substance with chain length of C5 and C7.

In the first key study, the short term toxicity of CAS 68424-31-7 to freshwater fish was investigated in a semi-static limit test (Combert and Caunter, 1991) conducted according to a guideline similar to OECD 203 using Salmo gairdneri as a test organism. This study determined LC50 (96h) > 1000 mg/L (nominal). The test material did not dissolved completely in the dilution water. No mortality was observed within the tested concentration (1000 mg/l nominal) during 96h exposure under test conditions. Based on these results it can be concluded that no toxicological effects on freshwater fish are expected up to limit of water solubility.

In a further study with decanoic acid, mixed esters with heptanoic acid, octanoic acid, pentaerythritol and valeric acid (CAS No. 71010-76-9) the short-term toxicity of to freshwater fish was investigated according to OECD 203 under static conditions using Brachydanio rerio as test organism (Lili, 2009). Nominal test concentrations of 100 and 150 mg/L were applied. Test substance monitoring using TOC analysis measured test concentrations of 0.696 and 0.704 mg/L, respectively. Undissolved test material was not removed from the test system; however, this is considered negligible, because no mortality was observed in any treatment and the control throughout the test period of 96 h. Hence, the 96 h-LC50 is determined to be > 0.704 mg/L (arithmetic mean) and thus above the limit of water solubility (< 0.02 mg/L).

In addition, short-term toxicity of fatty acids, C5-9 tetraesters with pentaerythritol (CAS 67762-35-2) to freshwater fish was investigated in a study according to OECD 203 under static conditions using Cyprinus carpio as test organism (Migchielsen, 2012). A nominal test concentration of 100 mg/L (prepared as WAF) was applied. Test substance monitoring measured a concentration of 4.8 mg/L. The final test solution was slightly hazy with a floating layer; however, this is considered negligible, because no mortality was observed in the treatment throughout the test period of 96 h. Hence, the 96 h-LL50 is determined to be > 100 mg/L (nominal) and > 4.8 mg/L (measured) and thus above the limit of water solubility (< 0.006 mg/L, purified water).

These results were supported by a study conducted according to EPA OTS 797.1400 investigating the toxicity of fatty acids, C8-10 mixed esters with dipentaerythritol, isooctanoic acid, pentaerythritol and tripentaerythritol (CAS 189200-42-8) on Pimephales promelas (Targia, 1994). No effects were observed up to the highest tested concentration resulting in a LC50 > 5 mg/L after a 96 h exposure period.

Based on these results from structurally related read-across substances (in accordance to Regulation (EC) No 1907/2006 Annex XI, 1.5) which are characterized by a similar ecotoxicological profile, it can be concluded that reaction mass of Heptanoic acid 3-pentanoyloxy-2,2-bis-pentanoyloxymethyl-propyl ester, Heptanoic acid 2-heptanoyloxymethyl-3-pentanoyloxy-2-pentanoyloxymethyl-propyl ester and Heptanoic acid 3-heptanoyloxy-2-heptanoyloxymethyl-2-pentanoyloxymethyl-propyl ester (former CAS 68441-94-1) will not exhibit short-term toxic effects to freshwater fish up to the limit of water solubility.

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; no toxicological effects up to the limit of water solubility.