Decanoic acid, mixed esters with octanoic acid and pentaerythritol

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Ames test (OECD 471): negative with and without metabolic activation in S. typhimurium TA 1535, TA 1537, TA 1538, TA 100 and TA 98, and E. coli WP2 uvrA.

Chromosome aberration (OECD 473): negative in CHO cells with and without metabolic activation

Gene mutation in mammalian cells (OECD 476): negative in mouse lymphoma L5178Y cells with and without metabolic activation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

JUSTIFICATION OF THE READ-ACROSS ANALOGUE (RA-A) APPROACH

The target substance Tetraesters of 2,2-bis(hydroxymethyl)propane-1,3-diol and decanoic and octanoic acid (CAS No. 68441-68-9) is an ester of pentaerythritol and fatty acids of a chain length of C8 and C10. The analogue approach covers 10 source substances, all of them are polyol esters covering a variety of polyols (pentaerythritol, dipentaerythritol and trimethylolpropane) and fatty acid moieties (linear: C5-18; branched: C5, C8 and C9; unsaturated: C18:1, C18:2 and C18:3).

The available data allows for an accurate hazard and risk assessment of all source substances and the target substance. Therefore, the read-across analogue (RA-A) approach is applied for the assessment of human health hazards of the target substance. Potential human health effects of the target substance are predicted by using adequate and reliable data for source substances within the analogue approach in accordance with Annex XI, Item 1.5, of Regulation (EC) No 1907/2006. In particular, for each specific endpoint the source substance(s) structurally closest to the target substance is/are chosen for read-across, with due regard to the requirements of adequacy and reliability of the available data. Structural similarities and similarities in properties and/or activities of the source and target substance are the basis of read-across.

A detailed justification of the read-across is provided in IUCLID section 13.

Target and source substances covered by the RA-A approach:

ID	CAS No.	EC No.	Chemical name	Fatty acid chain length	Type of alcohol	Degree of esterification	Molecular Formula	MW [g/mol]
Target	68441-68-9	270-472-2	Decanoic acid, mixed esters with octanoic acid and pentaerythritol	C8, C10	PE	Tetra	C37H68O8; C45H84O8	640.93 - 753.14
Source 1	11138-60-6	234-392-1	Fatty acids, C8-10 (even numbered), di- and triesters with propylidynetrimethanol	C8, C10	TMP	Tri	C30H56O6; C36H68O6	512.78 - 596.94
Source 2	15834-04-5	239-937-7	2,2-bis[[(1-oxopentyl)oxy]methyl] propane-1,3-diyl divalerate	C5	PE	Tetra	C25H44O8	472.62
Source 3	71010-76-9	275-118-0	Decanoic acid, mixed esters with heptanoic acid, octanoic acid, pentaerythritol and valeric acid	C5, C5iso, C6, C7, C8, C9, C10	PE	Tetra	C25H44O8; C33H60O8; C45H84O8	472.62 - 753.14
Source 4	146289-36-3	--	Pentaerythritol ester of pentanoic acids and isononanoic acid	C5, C5iso, C9branched	PE	Tetra	C25H44O8; C41H76O8	472.62 – 697.04
Source 5	68424-31-7	270-291-9	Pentaerythritol tetraesters of n-decanoic, n-heptanoic, n-octanoic and n-valeric acids	C5, C7, C8, C10	PE	Tetra	C25H44O8; C45H84O8	472.62 – 753.14
Source 6	85536-35-2	287-517-7	Fatty acids, C5-9, mixed esters with dipentaerythritol and pentaerythritol	C5-9	PE and DiPE	Tetra and Hexa	C25H44O8; C41H76O8; C40H70O13; C60H110O13	472.62 - 1039.51
Source 7	68604-44-4	271-694-2	Fatty acids, C16-18 and C18-unsatd., tetraesters with pentaerythritol	C16, C17, C18, C18:1, C18:2, C18:3	PE	Tetra	C69H132O8; C77H148O8; C77H104O8	1089.78 - 1193.93
Source 8	189200-42-8	--	Fatty acids, C8-10 mixed esters with dipenaterythritol, isooctanoic acid, pentaerythritol and tripentaerythritol	C8-10, C8iso	PE and DiPE	Tetra	C37H68O8; C45H84O8; C41H76O8; C58H106O13; C70H130O13; C64H118O13	640.93 – 1179.77
Source 9	67762-53-2	267-022-2	Carboxylic acids, C5-9, tetraesters with pentaerythritol	C5-9	PE	Tetra	C25H44O8; C41H76O8	472.62 - 697.04
Source 10	85586-24-9	287-827-2	Fatty acids, C8-10, tetraesters with pentaerythritol	C8-10	PE	Tetra	C37H68O8; C45H84O8	640.93 - 753.14

DISCUSSION

In vitro gene mutation in bacteria

The target substance Decanoic acid, mixed esters with octanoic acid and pentaerythritol (CAS No. 68441-68-9) has been assessed for its mutagenic potential in a reverse mutation assay performed according to OECD Guideline 471 and under GLP conditions (BASF, 1991a). However, an additional strain is missing; either TA 102 or E. coli WP2 uvrA. Therefore, it is not guideline compliant and additional studies were needed for read across. The following Salmonella typhimurium strains were tested: TA 1535, TA 1537, TA 1538, TA 98 and TA 100. Tested strains were incubated with the test material dissolved in Tween 80/bidest. water at concentrations of 8, 40, 200, 1000 and 5000 µg/plate in the first and second experiment, with and without the addition of a metabolic activation system (Arochlor 1254 induced rat liver S9 mix). Vehicle, negative and appropriate positive controls were included in the study. The positive control substances induced statistically significant increases in the frequency of revertant colonies indicating the satisfactory performance of the test and the activity of the metabolizing system. No increase in the frequency of revertant colonies compared to concurrent negative controls was observed in all strains treated with the test material, neither in the presence nor in the absence of metabolic activation. No cytotoxicity was observed. In conclusion, the test substance did not induce point mutations by base-pair changes or frame-shifts in the genome of the strains tested.

In addition to the Ames test with the target substance, adequate data from source substances Fatty acids C8-10, mixed esters with dipentaerythritol, 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) were used to further assess the genetic toxicity.

The mutagenic potential of Fatty acids C8-10, mixed esters with dipentaerythritol, isooctanoic acid, pentaerythritol and tripentaerythritol (CAS 189200-42-8) was tested in a reverse mutation assay comparable to OECD Guideline 471 and performed under GLP conditions (ExxonMobil, 1995a). The following Salmonella typhimurium strains TA1535, TA1537, TA98, TA100 and TA1538 were used. Tester strains were incubated with the test material dissolved in acetone at concentrations of 0.5, 5, 50, 500, 5000 µg/plate in the first experiment and 50, 100, 500, 1000 and 5000 µg/plate in the repeat experiment, both performed with and without the addition of a metabolic activation system (Arochlor 1254 induced rat liver S9 mix). Vehicle, negative and appropriate positive controls were included in the study design. The positive control substances induced statistically significant increases in the frequency of revertant colonies indicating the satisfactory performance of the test and the activity of the metabolizing system. No increase in the frequency of revertant colonies compared with concurrent negative controls was observed in any strains treated with the test material, neither in the presence nor in the absence of metabolic activation. No cytotoxicity was observed, but beading of the test substance occured in the initial assay and repeat assay at 500 µg/plate and above with and without metabolic activation in all strains. In conclusion, the test substance did not induce point mutations by base-pair changes or frame-shifts in the genome of the strains tested.

In an Ames test conducted with the Fatty acids, 8-10 (even numbered), di- and triesters with propylidynetrimethanol (CAS 11138-60-6), Salmonella typhimurium strains TA 1535, TA 1537, TA 1538, TA 98, TA 100 and E.coli WP2 uvr A were treated according to OECD Guideline 471 and under GLP conditions (Exxon, 1996). The test substance was diluted in ethanol and test substance concentrations of 0, 10, 33, 100, 333 and 1000 µg/plate were tested in triplicate, both with and without the addition of a rat liver homogenate metabolising system (S9). Precipitation of the test substance was observed at and above 100 µg/plate. The test material caused no cytotoxicity up to the highest, precipitating dose. No significant increases in the frequency of revertant colonies were recorded for any of the bacterial strains, with any dose of the test material, either with or without metabolic activation.

In vitro cytogenicity / chromosome aberration in mammalian cells

No data on the in vitro cytogenicity / chromosome aberration in mammalian cells are available for the target substance. Therefore, reliable information from source substance Fatty acids C8-10, mixed esters with dipentaerythritol, isooctanoic acid, pentaerythritol and tripentaerythritol (CAS 189200-42-8) was used for read-across.

An in vitro mammalian chromosome aberration test was performed with Fatty acids C8-10, mixed esters with dipentaerythritol, isooctanoic acid, pentaerythritol and tripentaerythritol (CAS 189200-42-8) in Chinese hamster ovary cells (CHO cells), following a protocol comparable to OECD Guideline 473 and under GLP conditions (ExxonMobil, 1995b). Duplicate cultures of CHO cells were evaluated for chromosome aberrations in the presence and absence of metabolic activation (rat liver S9-mix). In the first experiment, cells were exposed to the test substance for 3 h with metabolic activation and for 16 h without metabolic activation with 16 h expression time. The test substance was dissolved in acetone and used at concentrations of 40, 80 and 160 µg/mL. In the second experiment cells were again exposed for 3 h with metabolic activation and for 16 h without metabolic activation with 16 h expression time. Additionally, cells were exposed for 3 h with metabolic activation and 16 h without metabolic activation followed by 40 h expression time. The same substance concentrations as in the first experiment were used. The test substance did not induce cytotoxicity, but a precipitate was visible in the second experiment at 160 µg/mL after 16 h incubation without metabolic activation. The precipitate was considered to be not relevant for the result of the experiment. Vehicle (solvent) controls induced aberration frequencies within the range expected for normal human lymphocytes. N-Methyl-N-Nitro-N-Nitrosoguanidine and 7,12-Dimethylbenz[a]anthracene were used as positive control materials inducing statistically significant increases in aberration frequencies indicating the satisfactory performance of the test and of the activity of the metabolizing system. Evaluation of 100 well-spread metaphase cells from each culture for structural chromosomal aberrations revealed no increase in the frequency of chromosome aberrations and polyploid cells at any dose level tested in comparison to the negative controls. The test material was therefore considered to be non-clastogenic to CHO cells in vitro.

In vitro gene mutation study in mammalian cells

Since no data are available for the source substance regarding in vitro gene mutation study in mammalian cells, read-across of adequate information from source substance 2,2-bis[[(1-oxopentyl)oxy]methyl] propane-1,3-diyl divalerate (CAS 15834-04-5) was applied.

An in vitro Mammalian Cell Gene Mutation Assay according to OECD Guideline 476 and under GLP conditions was performed with 2,2-bis[[(1-oxopentyl)oxy]methyl]propane-1,3-diyl divalerate (CAS 15834-04-5) in mouse lymphoma L5178Y cells (WoE, RA-A, 15834-04-5, 2010). In the first experiment, the cells were treated for 3 h with 0.03, 0.1, 0.3, 1, 3, 10, 33, 100 µg/mL in the presence or absence of S9-mix (8% (v/v)). In the second experiment, test concentrations of 0.03, 0.1, 0.3, 1, 3, 10, 33, 100 µg/mL were applied with metabolic activation (12%, v/v) for 3 h and 0.1, 1, 3, 10, 33, 100, 200, 250 µg/mL without metabolic activation for 24 h. The test substance was tested up to precipitating concentrations (100 µg/mL and above). Cyclophosphamide and methylmethanesulfonate were used as positive controls with and without S9 mix, respectively. No toxicity was observed and all dose levels were evaluated in the absence and presence of S9-mix. Positive and negative controls were valid and within the range of the historical control data. No significant increase in the mutation frequency at the TK locus was observed after treatment with the test substance either in the absence or in the presence of S9-mix. It was concluded that the test substance is not mutagenic in the mouse lymphoma L5178Y test system under the experimental conditions described.

CONCLUSION

Based on the negative results of the in vitro mutagenicity and clastogenicity studies performed with source substances, no mutagenic potential is expected for the target substance.

Justification for classification or non-classification

According to Article 13 of Regulation (EC) No. 1907/2006, information on intrinsic properties of substances may be provided by means other than tests e.g. by transferring information of structurally related substances to a target substance,

provided that conditions set out in Annex XI are met. Annex XI, sec. 1.5, states that “Substances whose physicochemical, toxicological and ecotoxicological properties are likely to be similar or follow a regular pattern as a result of structural similarity may be considered as a group, or ‘category’ of substances. (...) This avoids the need to test every substance for every endpoint".

Therefore, Article 13 and Annex XI of Regulation (EC) No. 1907/2006 define the read-across concepts:

(i) read-across based on grouping of substances (category approach) - RA-C approach

(ii) read-across from supporting substance (structural analogue or surrogate) - RA-A approach.

Here the RA-A approach is applied to fill data gaps by transferring data from structural analogues to the target substance. As a result, unnecessary animal testing is avoided. Therefore, based on the analogue read-across approach, the results on genetic toxicity for the target and source substances do not meet the classification criteria according to Regulation (EC) 1272/2008, and are therefore conclusive but not sufficient for classification.