Fatty acids, C12-18 (even-numbered), 3-methylbutyl esters

Endpoint summary

Description of key information

Skin, rabbit: not irritating
Eye, rabbit: not irritating

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

Data on the skin and eye irritation potential of Fatty acids, C12-18, even numbered, 3-methylbutyl esters (CAS 1314963-50-2)

are not available. The assessment of irritation/corrosion potential was therefore based on studies conducted with analogue substances as part of a read across approach, which is in accordance with Regulation (EC) No. 1907/2006, Annex XI, 1.5. 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 for the analogue read-across approach is provided in the technical dossier (see IUCLID Section 13).

Skin irritation

CAS 163961-32-8

Fatty acids, C16-18 and C18-unsaturated, branched and linear, butyl esters (CAS 163961-32-8) was tested in an acute dermal irritation study in rabbits according to OECD guideline 404 (Sanders, 2002a). The shaved skin of three New Zealand White rabbits was exposed to 0.5 mL of the test substance (no data on purity) for 4 hours under semi-occlusive conditions. 24, 48 and 72 hours after patch removal the test sites were examined for evidence of primary irritation and scored according to Draize. Slight erythema and oedema (grade 1, respectively) occurred in all treated skin sites, which were all fully reversible within 48 or 72 hours. Based on the study results, the test substance shows no skin irritating potential.

CAS 34316-64-8

An acute skin irritation study was performed with Hexyl laurate (CAS 34316-64-8) according to a protocol similar to OECD guideline 404 (Masson, 1987). The intact and incised skin of 6 male New Zealand rabbits was treated with 0.5 mL of the test material (no data on purity) for 24 hours under occlusive conditions. The animals were observed for 72 h and scoring according to the Draize scoring system was performed 24 and 72 h after patch removal. Slight to moderate erythema (mean scores = 1.0, 1.67, 1.67, 0.67, 1.0, and 2.0) as well as very slight oedema (mean scores = 0.0, 0.67, 0.0, 0.0, 0.0, and 0.33) were observed assuming the 48-h reading to be the same as the 24-h reading. Full reversibility within the observation period was observed only for one animal. The results for incised skin were not taken into account for evaluation but were comparable. Due to the major deviation from the actual guideline, which requires semi-occlusive conditions, only 4 h exposure and an observation period of 14 days, the test material is not considered skin irritating as reversibility of the effects within an adequate observation period is assumed.

Eye irritation

CAS 163961-32-8

Fatty acids, C16-18 and C18-unsaturated, branched and linear, butyl esters (CAS 163961-32-8) was tested in an acute eye irritation study according to OECD guideline 405 (Sanders, 2002b). 0.1 mL of the unchanged liquid test substance (no data on purity) was instilled to the eye of three New Zealand White rabbits. Examination of treated eyes 1, 24, 48 and 72 hours after instillation according to the Draize scoring system revealed minimal to moderate conjunctival irritation in all treated eyes one hour after treatment with minimal conjunctival irritation in two treated eyes at the 24-hour observation. One treated eye appeared normal at the 24-hour observation and the two remaining treated eyes appeared normal at the 48-hour observation. One animal showed slight discharge at 24 hours.

CAS 110-27-0

An acute eye irritation study with Isopropyl myristate (CAS 110-27-0) was performed according to a protocol similar to OECD guideline 405 on 3 New Zealand White rabbits (Palanker, 1977). One eye of the rabbits was exposed to 0.1 mL of the undiluted test substance (no data on purity) and scored for eye reactions. The animals were observed for 7 days and scoring was performed 24, 48 and 72 h and 4 and 7 days after application. Only conjunctival redness (grade 1) was observed in two animals at the 24 h reading that was fully reversible within 48 h. No effects on conjunctival swelling, iris, or cornea were observed. Thus, it can be concluded that the test material has no potential for eye irritation.

CAS 20292-08-4

An acute eye irritation test performed according to OECD guideline 405 to evaluate the eye irritation potential of 2-Ethylhexyl Laurate (CAS 20292-08-4) is available (Bouffechoux, 1996). The test substance (no data on purity) was instilled in the conjunctival sac of three New Zealand rabbits. The animals were observed for 7 days and scoring of iris, cornea and conjunctivae according to the Draize scoring system was performed 1, 24, 48, 72 hours and 7 days after application. Slight conjunctival effects (mean score = 0.33 in all animals) were observed up to 24 h but was fully reversible within 48 h. No information is given if these effects were reddening or swelling of the conjunctivae as only a summary of the results is available. However, based on the results of the study the test substance is not considered eye irritating and classification is not warranted.  

Overall conclusion for skin and eye irritation

The reliable data available for the read-across analogue substances did not show any skin or eye irritation effects. Therefore, Fatty acids, C12-18, even numbered, 3-methylbutyl esters (CAS 1314963-50-2) is not considered to be a skin irritant or an eye irritant.

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 the 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 the source and target substances and overall quality assessment (refer to the endpoint discussion for further details).

Justification for classification or non-classification

According to Article 13 of Regulation (EC) No. 1907/2006 "General Requirements for Generation of Information on Intrinsic Properties of substances", information on intrinsic properties of substances may be generated by means other than tests e.g. from information from structurally related substances (grouping or read-across), provided that conditions set out in Annex XI are met. Annex XI, "General rules for adaptation of this standard testing regime set out in Annexes VII to X” 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". Since the analogue concept is applied to Fatty acids, C12-18, even numbered, 3-methylbutyl esters (CAS 1314963-50-2), data will be generated from data for reference source substance(s) to avoid unnecessary animal testing. Additionally, once the analogue read-across concept is applied, substances will be classified and labelled on this basis.

Therefore, based on the analogue read-across approach, the available data on skin and eye irritation 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.