Hexadecyl 2-ethylhexanoate

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Justification for grouping of substances and read-across

There are no reliable data available for the sensitising properties of Hexadecyl 2-ethylhexanoate (CAS 59130-69-7). In order to fulfil the standard information requirements set out in Annex IX in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006, read-across from structurally related substances was conducted.

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 health, 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, 1.5, of Regulation (EC) No 1907/2006, whereby substances may be predicted as similar provided that their physicochemical, toxicological and ecotoxicological properties are likely to be similar or follow a regular pattern as a result of structural similarity.

Sensitisation

CAS	59130-69-7	111937-03-2	59219-71-5
Chemical name	Hexadecyl 2-ethylhexanoate	Isononaoic acid, C16-18 alkyl esters	Isononyl isononanoate
MW	368.7 g/mol	362.7 g/mol	284.49 g/mol
Skin sensitisation	RA: CAS 111937-03-2, CAS 59219-71-5	Experimental data: not sensitising	Experimental data: not sensitising

 

The above mentioned substances are considered to be similar on the basis of the structural similarity resulting in similar properties and/or activities. The available endpoint information is used to predict the same endpoints for Hexadecyl 2-ethylhexanoate (CAS 59130-69-7).

A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13).

Discussion

Skin sensitisation

There are no data available on the skin sensitising potential ofHexadecyl 2-ethylhexanoate. In order to fulfil the standard information requirements set out in Annex VII, 8.3, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006 read-across from the structurally related analogue substancesIsononaoic acid, C16-18 alkyl estersandIsononyl isononanoateis conducted.

A skin sensitising study on Isononanoic acid, C16 -18 alkyl esters was performed in 1972 using 5 male guinea pigs (Potokar, 1972). Upon intradermal induction and intradermal challenge with a 25 % oily test substance solution no differences in the skin reactions between control and test group were observed. The study was only available as a short summary and the small number of experimental animals (5 males) is not sufficient for assessment.

Data are available from a human repeated insult patch test with the analogue substanceIsononyl isononanoate (Harrison, 1997). For the induction exposure 98 subjects were exposed to 0.2 mL undiluted test substance for 24 h under occlusive conditions. Nine induction exposures were performed within 3 weeks. Readings for skin irritation were performed 48 h after patch removal. The challenge was performed 2 weeks after the last induction. The patch with the test substance was applied for 24 h under occlusive conditions. The sensitisation reaction at the challenge site was assessed 0, 24, 48, and 72 h after patch removal. During the induction phase, 4/98 exhibited faint, minimal erythema or erythema (score ± or 1) and 2/98 had hyperpigmentation. Following the challenge treatment, 11/98 exhibited faint, minimal erythema or erythema (score ± or 1). These reactions are considered to be irritation reactions. In conclusion, test material did not induce skin sensitisation in any of the 98 subjects. 

QSAR prediction with the physicochemical properties of Isononanoic acid, C16 -18 alkyl esters do not suggest a sensitising potential (Wagner, 2013).

Conclusion

No data were available for the assessment of skin sensitisation of Hexadecyl 2-ethylhexanoate (CAS No. 59130-69-7). No skin sensitisation was observed in guinea pigs after treatment with the structural analogue Isononyl isononanoate (CAS No. 59219-71-5). In addition, data from a human repeated insult patch test with the analogue substance Isononaoic acid, C16-18 alkyl esters (CAS No. 111937-03-2) also revealed no skin sensitising properties. Based on the similar structure and PC parameters (see “Toxicokinetic, metabolism and distribution”) and the fact that no alert was found regarding protein binding for skin sensitization by OASIS v1.1 the read-across was supposed to be appropriate.In conclusion, the available data on the skin sensitisation ofHexadecyl 2-ethylhexanoateand structural analogue substances indicate thatHexadecyl 2-ethylhexanoateis not sensitising to the skin.

Migrated from Short description of key information:
Based on the available data on the analogue Isononanoic acid, C16-18 alkyl esters as well as on QSAR information and human HRIPT data, there are no indications for a sensitising potential of hexadecyl 2-ethylhexanoate.

Justification for selection of skin sensitisation endpoint:
Hazard assessment is conducted by means of read-across from structural analogues. All available studies are adequate and reliable based on the identified similarities in structure and intrinsic properties between source and target substances and overall quality assessment (refer to the endpoint discussion for further details).

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

Justification for selection of respiratory sensitisation endpoint:
Study not required according to Annex VII-X of Regulation (EC) No 1907/2006.

Justification for classification or non-classification

Based on read-across from the structurally similar substances, the available data on skin sensitisation do not meet the classification criteria according to Regulation (EC) 1272/2008 or Directive 67/548/EEC, and are therefore conclusive but not sufficient for classification.