Fatty acids, C16-18, calcium salts

Carcinogenicity

Description of key information

The 2-year oral carcinogenic study in rats with sodium oleate administered in the drinking water (no guideline specified) gave a NOAEL of 5% sodium oleate in the water, the maximum concentration administered. No evidence of increased incidence of tumours was observed following treatment. On the basis of the long history of safe use of fatty acid soaps in greases, the substances in the category are not considered to be carcinogens.

Key value for chemical safety assessment

Carcinogenicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

Study duration:

chronic

Species:

rat

Quality of whole database:

Limited. The study is taken from a review documents (HERA 2002) citing a published test. No guideline was stated but a standard procedure was used. The data are considered reliable and suitable for use for this endpoint since they are peer-reviewed prior to publication.

Carcinogenicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Carcinogenicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Not classified for carcinogenicity. No treatment-related increase in tumour incidence

Additional information

The substances in the category are considered to be similar on the basis that they have common structures of a calcium ion varying only by the length of the fatty acid chain and the presence of unsaturated and/or hydroxyl functional groups. As a result it is expected that the substances will have similar, predictable properties. REACH Annex V, Entry 9, groups fatty acids and their potassium, sodium, calcium and magnesium salts, including C6 to C24, predominantly even-numbered, unbranched, saturated or unsaturated aliphatic monocarboxylic acids. Provided that they are obtained from natural sources and are not chemically modified, the substances included in REACH Annex V, Entry 9 are exempt from registration, unless they are classified as dangerous (except for flammability, skin irritation or eye irritation) or they meet the criteria for PBT/vPvB substances. The metal fatty acid substances in the category are therefore not expected to be hazardous. Due to the close structural similarity and the narrow range of carbon chain numbers covered in this category, the carcinogenicity properties are expected to be predictable across the category.

Since REACH Annex V groups together calcium, potassium, sodium and magnesium salts of C6 to C24 fatty acids as being potentially exempt from registration, these metal cations are therefore not considered to contribute to any health hazard. On this basis, relevant published or proprietary data on any potassium, sodium or magnesium salt within the fatty acid category range of C14 to C22 can be used to read across to the calcium salts of C14-C22 fatty acid category.

Fats and oils are commonly used as controls and vehicle diluents/solvents in long term toxicity studies, e.g. corn (mazola) oil. On this basis they are considered not to possess carcinogenic activity.

A two-year carcinogenicity study in rats with sodium oleate (C18 unsaturated) administered in drinking water showed no significant difference between the incidence of tumours between the treated and control groups, and it was concluded that this substance did not exhibit tumourigenic potential in rats under the conditions of the test.

On the basis of long history of safe use of fatty acid soaps in greases, the substances in the category are not considered to be carcinogens.

Justification for selection of carcinogenicity via oral route endpoint:
A valid carcinogenicity study on sodium oleate (C18) that is relevant to the calcium salts of C14-C22 fatty acids and the results can be read across to the category members.