2,2-bis(hydroxymethyl)propane-1,3-diyl didocosanoate

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 no in vivo data on the skin sensitisation potential of 2,2-bis(hydroxymethyl)propane-1,3-diyl didocosanoate (CAS 68258-72-0). The assessment was therefore based on QSAR modelling and 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 sensitisation

QSAR modelling

CAS 68258-72-0

The potential for 2,2-bis(hydroxymethyl)propane-1,3-diyl didocosanoate to bind to proteins, known to be an indication of potential skin sensitising properties, was predicted in the QSAR OECD Toolbox (3.3.5.17). No structural protein binding alerts for skin sensitisation have been predicted using this model (OASIS v. 1.3; Wieneke, 2016).

Animal data

CAS 68424-31-7

A Guinea pig maximisation test was performed with pentaerythritol tetraesters of n-decanoic, n-heptanoic, n-octanoic and n-valeric acids under GLP conditions and using a protocol similar to OECD Guideline 406 (Lees, 1991). 20 test and 10 control albino guinea pigs were induced epicutaneously on both flanks with undiluted test substance under occlusive conditions for 6 hours. The treatment was repeated on Day 7 and 14. On Day 28, 14 days after the last induction, the challenge treatment was performed by topical application of the test substance at 100% (left flank) and 30% (right flank) to all animals for 6 hours, under occlusive conditions. Skin reactions were evaluated 24 and 48 hours after the challenge application. No skin reactions were observed in treated and control animals during the 1st and 2nd reading. No further information was given in the study report. There was no positive control included in the study. Based on the results, the test substance had no sensitising effect in guinea pigs under the experimental conditions.

Human data

CAS 62125-22-8

A non-guideline repeated insult human patch test (RIPT) was conducted to assess the sensitizing potential of 2,2-bis[[(1-oxoisooctadecyl)oxy]methyl]-1,3-propanediyl in 55 male and female volunteers from the general population, aged 19 – 56 years (Frank, 1985). During the induction phase, volunteers were subjected to 10 repeated semiocclusive applications of the unchanged test substance. Patches were placed on the back of volunteers for 24 hours, followed by a 24 hour rest period (48 hours on weekends). The 10 induction patches were applied to the same site. The induction phase was followed by a resting period of 14 days. A challenge patch was applied to the same site on the back and to a naïve site, once only. Skin reactions were assessed 24 and 48 hours after patch removal. None of the human volunteers showed any skin reactions at the end of the study period. Therefore, the test substance is not considered sensitising to humans under the conditions of the study.

 

Conclusion

The OECD QSAR Toolbox did not predict protein binding by the target substance. A GPMT study performed with a source substance was negative, and the result of a human repeated insult patch test performed with a source substance was likewise negative. Taking into account the available information, 2,2-bis(hydroxymethyl)propane-1,3-diyl didocosanoate is not expected to be skin sensitising.

Migrated from Short description of key information:
Skin sensitisation (WoE, QSAR, GPMT, RIPT): not sensitising

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 the 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

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 2,2-bis(hydroxymethyl)propane-1,3-diyl didocosanoate (CAS 68258-72-0), 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 sensitisation do not meet the classification criteria according to Regulation (EC) 1272/2008, and are therefore conclusive but not sufficient for classification.