Isooctadecyl isooctadecanoate

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Justification for read-across

There are only limited human data available on the skin sensitisation potential of the registered substance (CAS 41669-30-1). In order to fulfil the standard information requirements set out in Annex VIII, 8.3, 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 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 to avoid the need to test every substance for every endpoint).

 

Overview of skin sensitisation 

 

CAS	Chemical name	Molecular weight	Sensitisation
41699-30-1	isooctadecyl isooctadecanoate	536.95	RA: CAS 93803-87-3
93803-87-3	2-octyldodecyl isooctadecanoate	565.01	Experimental result: not sensitising

 

The above mentioned substances are considered to be similar to each other based on structurally similar properties and/or activities. Therefore, the available data on the source substance has been read-across to isooctadecyl isooctadecanoate (CAS 41669-30-1).

The target substance is characterized by a branched C18 fatty acid esterified with an aliphatic, but branched

C16 and C18 alcohol. The source substance is structurally very similar to the target substance. It is characterized by isostearic acid esterified with a branched alcohol (2-octyldocdecanol). A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13).

CAS 93803-87-3

 

The skin sensitising potential of 2-octyldodecyl isooctadecanoate (CAS 93803-87-3) was evaluated in a Guinea Pig Maximisation Test (GPMT) performed according to a protocol similar to OECD TG 406 (Busschers, 1998). The first induction (Day 1) was performed on 10 animals by intradermal injection of the undiluted test substance. On Day 7, the animals were treated with 10% sodium lauryl sulphate (SDS) in vaseline, to induce skin irritation. During the second induction on Day 8, the undiluted test substance was applied topically and held in place with a semi-occlusive dressing for 48 h. On Day 21, all the animals were challenged with the undiluted test substance via topical application under semi-occlusive conditions for 24 h. 5 guinea pigs in the control group were treated according to the same protocol with the vehicle (corn oil). 48 h after the intradermal induction, slight to severe erythema was noted at most of the injection sites in the treated and control animals. 4/5 control animals also exhibited necrosis at the FCA/test substance injection site. These effects were caused primarily by the injection and not by a reaction to the test substance. Following the topical induction, severe erythema and scabs were observed at the test site in 3/10 treated animals. No sensitisation was observed in the treated animals during the reading time points 48 and 72 h after the challenge. The test substance did not cause skin sensitisation under the conditions of the study.

 

CAS 41669-30-1

 

The sensitising potential of the registered substance (CAS 41669-30-1) was assessed in a repeated insult patch test (epicutaneous test) on 25 human volunteers (5 males, 20 females) (Rigot-Muller, 1997). During the induction phase, volunteers were exposed in total nine times at an average of 3 times/week. An occlusive patch with 0.02 mL of the test substance, in a 30% dilution in Kernel stone oil, was applied to a surface area of 50 mm² on the left arm (bending side) for 48 h or about 72 h in the case of the 3^rd and 6^th applications. The challenge was performed approximately two weeks after the last induction. The challenge patch was applied to the back area (left side of the spine) and remained in place for 48 h. The sensitisation reaction at the challenge site was assessed at 24 and 48 h after patch removal. The repeated cutaneous applications of the registered substance, diluted at 30%, under occlusive patch, in healthy adult volunteers, did not result in any cutaneous sensitisation reactions.

Conclusions for skin sensitisation 

Based on read-across and substance-specific data, sufficient evidence is available to conclude that the substance isooctadecyl isooctadecanoate (CAS 41669-30-1) is not a skin sensitizer. 

Migrated from Short description of key information:
Skin sensitisation (OECD 406): not sensitising

Justification for selection of skin sensitisation endpoint:
Hazard assessment is conducted by means of read-across from a structural analogue. The selected study is the most adequate and reliable study based on the identified similarities in structure and intrinsic properties between source and target substance and overall assessment of quality, duration and dose descriptor level (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 following an analogue approach, the available data on the skin sensitisation potential 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.

There are no data available on respiratory sensitisation.