Hexadecyl (R)-12-hydroxyoleate

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 eye irritation of Hexadecyl (R)-12-hydroxyoleate (CAS 10401-55-5) are not available. The assessment was therefore based on studies conducted with analogue (source) 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 10401-55-5

A skin irritation study was performed with Hexadecyl (R)-12-hydroxyoleate (CAS 10401-55-5), according to a protocol similar to OECD guideline 404 (Dufour, 1994). The results of the conducted study were reported in a summary with limited information. However, as basic data are provided sufficient for hazard assessment, the study was considered as reliable (reliability 2). An undisclosed amount of the test substance was applied to the shaved skin of 3 male rabbits and held in place with a semi-occlusive dressing for an undisclosed amount of time. The skin irritation effects were scored 1, 24, 48 and 72 hours after patch removal. One hour after patch removal, very slight erythema (Klimisch score 1) was observed in 3/3 animals. At the 24-hour reading time point 2/3 rabbits showed very slight erythema and 1/3 rabbits well defined erythema (score 2), which persisted in all animals until the 72-hour reading time point. No edema was observed 1 hour after patch removal. From 24 hours until at least 72 hour after patch removal, 1/3 rabbits showed very slight edema (score 1). One animal also showed slight edema at the 72-hour reading time point only, while 1/3 did not have any edema at any time point. All skin irritation effects had cleared completely by day 7 of the observation period. The mean erythema scores (over 24, 48 and 72 hours) were 1.00, 2.00 and 1.00 while the mean edema scores (over 24, 48 and 72 hours) were 0, 1.00 and 0.33. The test substance is not considered to be irritating to the skin.

Eye irritation

CAS 72576-80-8

The eye irritation potential of Hexadecanoic acid, isooctadecyl ester (CAS 72576-80-8) was evaluated in a study performed according to OECD 405 and in compliance with GLP (Bouffechoux , 1999). 0.1 mL test substance was instilled into one eye of 3 male rabbits, and the eyes remained unwashed. The eye irritation effects were scored according to the Draize scoring system 1, 24, 48, and 72 hours, and 7 days after application. At the 1-hour reading time point, 3/3 rabbits had slight-moderate conjunctivae (scores 1, 1,2), and 2/3 had slight chemosis (score 1). The chemosis had cleared by the 24-hour reading time point; while 3/3 animals still had slight conjunctivae (score 1). All eye irritation effects were fully reversible within 48 hours. No cornea opacity or iris changes were observed in any rabbit at any time point. The mean conjunctivae score (over 24, 48 and 72 hours) was 0.33, 0.33 and 0.33, while the mean chemosis score (over 24, 48 and 72 hours) was 0, 0 and 0. The mean cornea score and iris score (over 24, 48 and 72 hours) was 0 for all animals. Based on the results of the study, the test substance is not considered to be irritating to the eyes.

CAS 3234-85-3

An eye irritation study was performed with Tetradecanoic acid, tetradecyl ester (CAS 3234-85-3) according to a protocol similar to OECD 405, and summarised in a short report (Cade, 1976). 0.1 mL of a 50% solution of the test substance in corn oil was instilled into the eye of 6 rabbits. The eyes were not washed after the treatment. The eye irritation effects were scored according to the Draize scoring system 24, 48, and 72 hours after application. Slight conjunctivae (score 1) was observed in 4/6 animals at the 24-hour reading time point, which persisted in 1/6 rabbits until the 48-hour reading time point. The conjunctivae had cleared completely within 72 hours. No chemosis and no changes in cornea opacity or the iris were observed in any rabbit at any time point. The mean conjunctivae score (over 24, 48 and 72 hours) was 0.67, 0.33, 0, 0.33, 0.33 and 0. As a dilution was used, the results cannot be used for classification purposes.

Overall conclusion for skin and eye irritation

The available data on the target and source substances did not show any skin or eye irritation effects. Therefore, Hexadecyl (R)-12-hydroxyoleate is not considered to be a skin irritant and is not expected to be an eye irritant.

Justification for selection of skin irritation / corrosion endpoint:
The key study was selected.

Justification for selection of eye irritation endpoint:
Hazard assessment is conducted by means of read-across from structural analogues. The selected study is the most adequate and reliable study based on the identified similarities in structure and intrinsic properties between the source and target substance 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 Hexadecyl (R)-12-hydroxyoleate (CAS 10401-55-5), data will be generated from information on 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 target substance information and analogue read-across approach, the available data on 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.