Fatty acids, C8-10, octyl esters

Endpoint summary

Description of key information

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

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 grouping of substances and read-across

There are no data available for the skin and eye irritating potential of Fatty acids, C8-10, octyl esters (CAS 91031-98-0). In order to fulfil the standard information requirements set out in Regulation (EC) No 1907/2006, Annex VII and VIII, 8.1 and 8.2, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006, a 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 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 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.

Overview for skin and eye irritation

CAS #	Skin irritation	Eye irritation
91031-98-0 Target substance	RA: 2306-88-9 RA: 34316-64-8 RA: 20292-08-4	RA: 2306-88-9 RA: 20292-08-4 RA: 92044-87-6
2306-88-9	Not irritating	Not irritating
34316-64-8	Not irritating	--
20292-08-4	Not irritating	Not irritating
92044-87-6	--	Not irritating

 

The above mentioned substances are considered to be similar on the basis of structural similarity resulting in similar properties and/or activities. The available endpoint information is used to predict the same endpoints for Fatty acids, C8-10, octyl esters (CAS 91031-98-0).

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

Skin irritation

CAS 2306-88-9

Octyl octanoate (CAS 2306-88-9), representing a main component of Fatty acids, C8-10, octyl esters, was tested in an acute dermal irritation study in rabbits similar to OECD Guideline 404 (Potokar, 1991). Two New Zealand White rabbits were exposed to 0.5 mL of 1 or 5% test substance solution (no data on purity available) for 4 hours under occlusive conditions. 24 and 48 hours after patch removal the test sites were examined for evidence of primary irritation and scored according to Draize. No erythema or edema were detected. As the study is insufficient for assessment (only 5% dilution tested, occlusive method used, only 2 animals tested, substance purity not specified, only 48 h observation period in the absence of any irritation reaction) additional data was taken into account to assess the skin irritating potential of Fatty acids, C8-10, octyl esters (CAS 91031-98-0).

CAS 34316-64-8

Dodecanoic acid, hexyl ester(CAS 34316-64-8) was tested in a primary dermal irritation study similar to OECD Guideline 404 in male New Zealand White rabbits (Masson, 1987). The skin of six animals was exposed to the test substance (no data on purity) for 24 hours under occlusive conditions. Treated skin sites were evaluated according to the Draize scoring system 24 and 72 hours after application. At the time point 24 hours, three animals displayed erythema graded 2 and three animals displayed erythema grade 1. One animal showed edema grade 1. At time point 72 hours one animal showed erythema grade 2 and four animals showed erythema grade 1. One animal displayed edema grade 1. Since no reading was performed at 48 h, the score for this time point was assumed to be the same as the one observed at 24 h. Therefore, the mean value out of all six animals over 24, 48 and 72 h is 1.34 for erythema and 0.17 for edema, respectively. Based on the study results, the test substance exerts no or only mild skin irritating potential.

CAS 20292-08-4

2-Ethylhexyl laurate (CAS 20292-08-4) was tested in a primary dermal irritation study similar to OECD 404 in male New Zealand White rabbits (Bouffechoux, 1996). The skin of three animals was exposed to the test substance (no data on purity available) and evaluated according to the Draize scoring system until 7 days after application. At the time point 24 hours, all animals displayed erythema graded 2 and 3 animals displayed erythema grade 1. At time point 48 hours two animals showed erythema grade 2 and one animal showed erythema grade 1. At time point 72 hours one animal showed erythema grade 2. No edema was detected. Desquamative reaction, with moderated cutaneous extensive range index for 3 animals from day 4 to day 7 was observed. On day 7 no findings were detected. Based on the study results, the test substance exerts no or only mild skin irritating potential.

 

Eye irritation

CAS 2306-88-9

Octyl octanoate (CAS 2306-88-9), representing a main component of Fatty acids, C8-10, octyl esters, was tested for its acute eye irritation potential in a study performed equivalent to OECD Guideline 405 (Potokar, 1981). 0.1 mL of 1% test substance solution (no data on purity available) was instilled into one eye of 2 New Zealand rabbits. 2, 6, 24 hours later, treated eyes were examined for ocular lesions according to Draize. No signs of severe eye damage or irritation were observed. As the study is insufficient for assessment (only 1% dilution tested, reading time points only 2, 6 and 24 hours in the absence of any irritation reaction, only 2 animals tested) additional data was taken into account to assess the skin irritating potential of Fatty acids, C8-10, octyl esters (CAS 91031-98-0).

CAS 20292-08-4

2-Ethylhexyl laurate (CAS 20292-08-4) was tested for its acute eye irritation potential in a study performed according to OECD Guideline 405 (Bouffechoux, 1996). The test substance (no data on purity available) was instilled into one eye of 3 male New Zealand rabbits. 1, 24, 48 and 72 hours later, treated eyes were examined for ocular lesions according to Draize. After a single instillation, the test substance resulted in redness of the conjunctivae, which warranted a conjunctivae score of 2 in the first hour after application in two animals and of 1 in one animal. The irritation had completely resolved within 48 hours in all animals. No iridial irritation or corneal opacity was observed. Thus, the test material is not considered irritating to the eyes in this study.

CAS 92044-87-6

Fatty acids, coco, 2-ethylhexyl esters (CAS 92044-87-6) was tested for its acute eye irritation potential in a study performed according to OECD Guideline 405 (Weterings, 1987). The test substance (purity: approximately 100%) was instilled into one eye of 3 female New Zealand White rabbits. 1, 24, 48 and 72 hours later, treated eyes were examined for ocular lesions according to Draize. After a single instillation the test substance resulted in redness of the conjunctivae, which warranted a conjunctivae score of 1 in the first hour after application in two animals. The irritation had completely resolved within 24 hours in all animals. No iridial irritation or corneal opacity was observed. Two animals showed only slight swelling of the blood-vessels in the conjunctivae 1 hour after instillation. The effects were fully reversible 24 hours after instillation. The fluorescein analysis 24 hours after instillation did not reveal any epithelial damage. Thus, the test material is not considered irritating to the eyes in this study.

 

Conclusion:

There are three skin irritation studies available withoctyl octanoate (CAS 2306-88-9), representing a main component of Fatty acids, C8-10, octyl esters, and the structural similar substances dodecanoic acid, hexyl ester (CAS 34316-64-8) and 2-ethylhexyl laurate (CAS 20292-08-4). All studies revealed no or only mild indication of skin irritation.

Eye irritation potential has been evaluated based on an analogue read-across approach tooctyl octanoate (CAS 2306-88-9), representing a main component of Fatty acids, C8-10, octyl esters, 2-ethylhexyl laurate (CAS 20292-08-4) and Fatty acids, coco, 2-ethylhexyl esters (CAS 92044-87-6). In all in vivo studies, there was no indication of eye irritating potential.

Therefore, Fatty acids, C8-10, octyl esters (CAS 91031-98-0) is not considered to be skin or eye irritating.

Justification for selection of skin irritation / corrosion 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).

Justification for selection of eye irritation 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).

Justification for classification or non-classification

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