Glycerides, C16-18 mono-

Carcinogenicity

Description of key information

Based on expert judgment,  there is no evidence that members of the Glycerides category cause carcinogenicity.

Key value for chemical safety assessment

Carcinogenicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no study available

Carcinogenicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Carcinogenicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

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 group concept is applied to the members of the Glycerides category, data will be generated from data for reference source substance(s) to avoid unnecessary animal testing. Additionally, once the group concept is applied, substances will be classified and labelled on this basis.

Based on expert judgement, a testing proposal for a carcinogenicity study within the Glycerides category would be scientifically unjustified.

Additional information

Justification for grouping of substances and read-across

The Glycerides category covers aliphatic (fatty) acid esters of glycerol. The category contains both well-defined and UVCB substances with aliphatic acid carbon chain lengths of C2 (acetate) and C7-C22, which are mostly linear saturated and even numbered. Some of the substances in the category contain unsaturated fatty acids (e.g. oleic acid in 2,3-dihydroxypropyl oleate, CAS 111-03-5 or general fatty acids C16-22 (even) unsaturated in Glycerides, C14-18 and C16-22-unsatd., mono- and di-, CAS 91744-43-7). Some category members contain branched fatty acids. Branching is mostly methyl groups (e.g. isooctadecanoic acid, monoester with glycerol, CAS 66085-00-5 or 1,2,3-propanetriyl triisooctadecanoate, CAS 26942-95-0). In one category member the branching cannot be precisely located (Glycerides, C16-18 and C18-unsatd., branched and linear mono-, di- and tri, ELINCS 460-300-6). Hydroxylated fatty acids are present in three substances (Castor oil, CAS 8001-79-4; castor oil hydrogenated, CAS 8001-78-3 and 2,3-dihydroxypropyl 12-hydroxyoctadecanoate, CAS 6284-43-1). Hydroxylation occurs on C12 of stearic acid in all these substances. Acetylated chains are present in the last part of the category, comprising fatty acids from C8 to C18 (even) and also C18 unsaturated, additionally a C18 acetylated fatty acid is present with the acetic acid located in C12 position (e.g. Glycerides, castor oil mono-, hydrogenated acetates / 12-acetoxy-octadecanoic acid, 2,3-diacetoxy, CAS 736150-63-3). All glycerides build mono-, di- and tri-esters in variable proportions.

The available data allows for an accurate hazard and risk assessment of the category and the category concept is applied for the assessment of environmental fate, environmental and human health hazards. Thus where applicable, environmental and human health effects are predicted from adequate and reliable data for source substance(s) within the group by interpolation to the target substances in the group (read-across approach) applying the group concept in accordance with Annex XI, Item 1.5, of Regulation (EC) No 1907/2006. In particular, 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 grouping of chemicals and read-across is provided in the technical dossier (see IUCLID Section 13) and within Chapter 5.1 of the CSR.

In accordance with Column 2 of Annex X, 8.9.1, of Regulation (EC) No 1907/2006, a carcinogenicity study may be proposed by the registrant or may be required by the Agency in accordance with Articles 40 or 41 if: the substance has a widespread dispersive use or there is evidence of frequent or long-term human exposure, and the substance is classified as germ cell mutagen category 2 or there is evidence from the repeated dose study(ies) that the substance is able to induce hyperplasia and/or pre-neoplastic lesions.

There is no evidence that the members of the Glyceride category induce gene mutations in bacteria or chromosome aberrations in mammalian cells, as the results of all genotoxicity studies were consistently negative. Furthermore, in the available repeated dose toxicity studies and developmental studies, no substance-related increases in the incidence of hyperplasia or pre-neoplastic lesions were observed.

The available and relevant studies do not indicate that the members of the Glyceride category fulfil the criteria for classification as germ cell mutagen or that they are able to induce hyperplasia and/or pre-neoplastic lesions. Therefore, the conditions for a carcinogenicity study to be proposed or required set out in Column 2 of Annex X, 8.9.1, are not met. Furthermore, the weight of evidence from all available information leads to the conclusion that the members of the Glyceride category are not carcinogenic. Therefore, a carcinogenicity study is scientifically unjustified, will not be proposed and shall be omitted for reasons of animal welfare in accordance with Annex XI, 1.2, of Regulation (EC) 1907/2006.

Justification for selection of carcinogenicity via oral route endpoint:
No carcinogenicity study is required, since the substance is not mutagenic and no hyperplasia or pre-neoplastic lesions were observed in any of the available studies.

Justification for selection of carcinogenicity via inhalation route endpoint:
No carcinogenicity study is required, since the substance is not mutagenic and no hyperplasia or pre-neoplastic lesions were observed in any of the available studies.

Justification for selection of carcinogenicity via dermal route endpoint:
No carcinogenicity study is required, since the substance is not mutagenic and no hyperplasia or pre-neoplastic lesions were observed in any of the available studies.