3-[3-(pentanoyloxy)-2,2-bis[(pantanoyloxy)methyl]propoxyl]-2,2-bis[(pentanoyloxy)methyl]propyl pentanoate 3-{3-[(3,5,5-trimethylhexanoyl)oxy]-2,2-bis({[(3,5,5-trimethylhexanoyl)oxy]methyl}propoxy)-2,2-bis({[(3,5,5-trimethylhexanoyl)oxy]methyl}propyl 3,5,5-trimethylhexanoate

Endpoint summary

Description of key information

Skin irritation/corrosion: not irritating (OECD 404, GLP) 
Eye irritation: not irritating (OECD 405, GLP) 

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Justification for read-across approach

In accordance with Article 13 (1) of Regulation (EC) No 1907/2006, "information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI are met. In particular for human toxicity, information shall be generated whenever possible by means other than vertebrate animal tests", which includes the use of information from structurally related substances (grouping or read-across).

Having regard to the general rules for grouping of substances and read-across approach laid down in Annex XI, Item 1.5, of Regulation (EC) No 1907/2006, whereby toxicological properties may be predicted from data for reference substance(s) by interpolation to other substances on the basis of structural similarity, the following substances are selected as reference substances for assessment of toxicological endpoints, for which information gaps are identified.

Therefore, the analogue approach endpoint information for

-         acute toxicity via inhalation forFatty acids, C5-10, esters with pentaerythritol (CAS 68424-31-7) and Fatty acids, C5-9, mixed esters with dipentaerythritol and pentaerythritol (CAS 85536-35-2)

-         the subchronic oral repeated dose toxicity forpentanoic acid, mixed esters with pentaerythritol, isopentanoic and isononanoic acid (CAS No. 146289-36-3);

-         the genetic toxicity information for pentaerythritol tetravalerate (CAS 15834-04-5) and Fatty acids, C5-10, esters with pentaerythritol (CAS 68424-31-7)

-         and information for developmental toxicity for Fatty acids C8-10, mixed esteres with diPE, isooctanoic acid, PE and triPe (CAS 189200-42-8) and Trimethylolpropane Caprylate Caprate (CAS 11138-60-6)

are used to predict the same endpoints for dipentaerythritol ester of nC5/iC9 acids (CAS No. 647028-25-9). The analogue substances are considered to be similar on the basis of structural similarity and similar properties and/or activities.

The structural similarities are based on:

(1) common functional groups: The source (reference) and target substances are all characterised by ester bond(s) between a polyol and one or more carboxylic fatty acid chains. The polyol moiety of the source and target substances comprises structurally related molecules: pentaerythritol, di-pentaerythritol, tri-pentaerythritol and trimethylolpropane, all of which share a neopentane backbone as underlying common molecular structure. The fatty acid moieties comprise saturated linear and/or branched chains of 5 to 10 C-atoms length.

(2) common precursors and the likelihood of common breakdown products via biological processes, which result in structurally similar chemicals. The source and target substances are all UVCB substances, except pentaerythritol tetravalerate (CAS 15834-04-5) which is a monoconstituent, produced by esterification of the corresponding polyol and fatty acid mixtures. Ester bond formation is in principle a reversible reaction (hydrolysis). A slow stepwise hydrolysis of the ester bonds by gastrointestinal enzymes is identified as the biological process, by which the breakdown of the source and target substances results in structurally similar chemicals: the respective polyol and fatty acid moieties as stated above.

(3) a constant pattern in the changing of the potency of the properties between source and target substances: For the source and target substances, the constant pattern is characterised by similarities in the potency of properties. The available data on the target and the source substances show similarities in physico-chemical properties, in particular the high molecular weight of the substances. The molecular weight of Dipentaerythritol ester of nC5/iC9 acids ranges from 983 to 1096 g/mol and molecular weights of the target substances ranges from 472.62 to 1039.5 g/mol. In addition, the octanol/water partition coefficient of Dipentaerythritol ester of nC5/iC9 acids is > 6.2 (Lumsden, 2000) and available data on the calculated partition coefficients of the target substances are in the range of 6.74 to 13.59 (as published in respective dossiers on ECHA homepage). Furthermore, the target substance has a low water solubility (see toxicokinetics) and calculated water solubility of the source substances is considered to be low as well (Lumsden, 2000).

The available data on toxicological properties indicate that the source and target substances have a similar toxicokinetic behaviour; especially they are assumed to be slowly hydrolyses (see toxicokinetics). In addition, a low acute oral toxicity was seen for the source substance as well as for Trimethylolpropane Caprylate Caprate and Fatty acids, C5-10, esters with pentaerythritol (as published in respective dossiers on ECHA homepage). A low acute inhalation toxicity for Fatty acids, C5-9, mixed esters with dipentaerythritol and pentaerythritol and Fatty acids, C5-10, esters with pentaerythritol was observed as well (Parr-Dobranski, 1994a,b). Dipentaerythritol ester of nC5/iC9 acids is not skin or eye irritating and have not shown sensitising properties (Allen, 1999a,b,c) and the same is true for the source substances Fatty acids, C5-10, esters with pentaerythritol and Trimethylolpropane Caprylate Caprate (as published in respective dossiers on ECHA homepage). A low toxicity after repeated oral exposure (NOAEL > 1000 mg/kg bw/day) were observed for the source substance and for Fatty acids, C5-10, esters with pentaerythritol (Jones, 2000; Brammer, 1993) and for pentanoic acid, mixed esters with pentaerythritol, isopentanoic and isononanoic acid (NOAEL = 300 mg/kg bw/day; Müller, 1998). In addition, the available data on genotoxicity show that Dipentaerythritol ester of nC5/iC9 acids and the target substance Trimethylolpropane Caprylate Caprate are not genotoxic in the bacterial reverse mutation assay or clastogenic (Thompson, 1992; Wright, 2000; as published in respective dossier on ECHA homepage) and the source substance pentaerythritol tetravalerate did not show genotoxicity in a mammalian cell gene mutation assay (Verspeek-Rip, 2010). The target substance, Fatty acids, C5-10, esters with pentaerythritol did not show clastogenic properties in vivo as well (Griffiths, 1992) and no effect on intrauterine development was seen for Trimethylolpropane Caprylate Caprate and Fatty acids C8-10, mixed esteres with diPE, isooctanoic acid, PE and triPe.

In summary, all available data on the source and target substances show that the constant pattern is characterised by a lack of potency of properties.

In order to avoid the need to test Dipentaerythritol ester of nC5/iC9 acids for every endpoint, the analogue concept (read-across approach) is applied for the assessment of human health hazards. Thus where applicable, human health effects are predicted from adequate and reliable data for the reference substances by interpolation to Dipentaerythritol ester of nC5/iC9 acids in accordance with Annex XI, Item 1.5 of Regulation (EC) No 1907/2006.

A detailed justification for the grouping of chemicals and read-across is provided in the technical dossier (see IUCLID Section 13) as well as in the Chemical Safety Report.

Skin irritation

The skin irritation properties of Dipentaerythritol ester of nC5/iC9 acids were tested in a study according to OECD guideline 404 in compliance with GLP (Allen, 1999).

In the study, 3 New Zealand White rabbits were exposed to 0.5 mL of the undiluted test substance, applied onto the shaved skin for 4 h using a semiocclusive dressing. Thereafter, the remaining test substance was removed, the treated skin was observed and evaluated at 1, 24, 48 and 72 h and 7 days post-application.

The observed skin effects consisted of slight erythema in 2/3 animals from 24 h up to 72 h being fully reversible within 7 days. In the remaining animal, slight erythema was observed at the 24 and 48 h reading time points only. In 2/3 animals mean erythema scores (24, 48 and 72 h) were 1, in one animal the mean erythema score was 0.67. No edema formation (mean over 24, 48 and 72 h) or further local or systemic effects were apparent in any animal during the study period.

Under the experimental conditions described, it was concluded, that no evidence of skin irritation properties were seen after treatment with Dipentaerythritol ester of nC5/iC9 acids.

Eye irritation

The eye irritation properties of Dipentaerythritol ester of nC5/iC9 acids were tested in a study according to OECD guideline 405 in compliance with GLP (Allen, 1999).

In a group of 3 New Zealand White rabbits (1 male and 2 females), 0.1 mL of the undiluted test substance was applied into the conjunctival sac ofone eye (the untreated eye served ascontrol)in a single application without washing. The eyes were observed and reactions were evaluated 1, 24, 48 and 72 h after application.

No effects on corneal opacity and iris were noted at any time point in any animal. However, mild and moderate conjunctival redness were noted at the 1 h observation in 1/3 and 2/3 animals, respectively. Moderate conjunctival redness persisted in 2 animals up to the 24 h reading time point (mean score over 24, 48 and 72 h in each of the two animals: 0.33). Minimal chemosis was observed in all treated animals at the 1 h observation.Treated eyes appeared normal 24 to 48 h after treatment.

No further local or systemic effects were observed in any animal during the study period.

Under the experimental conditions described, it was concluded, that no evidence of eye irritation properties were seen after treatment with Dipentaerythritol ester of nC5/iC9 acids.

Justification for selection of skin irritation / corrosion endpoint:
Only one study available.

Justification for selection of eye irritation endpoint:
Only one study available.

Justification for classification or non-classification

The available data on the skin and eye irritating potential of Dipentaerythritol ester of nC5/iC9 acids (CAS No. 647028-25-9) do not meet the criteria for classification according to Regulation (EC) 1272/2008 or Directive 67/548/EEC, and the data are therefore conclusive but not sufficient for classification.