Octadecanoic acid, C16-20-branched alkyl esters

Endpoint summary

Description of key information

Oral (OECD 401): LD50 > 2000 mg/kg bw

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

The available information comprises an adequate, reliable (Klimisch score 2) and consistent study from a reference substance with similar structure and intrinsic properties. Read-across is justified based on common precursors and breakdown products of hydrolysis and consistent trends in environmental fate, ecotoxicological and toxicological profile (refer to the endpoint discussion for further details).
The selected study is thus sufficient to fulfil the standard information requirements set out in Annex VII, 8.5, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006.

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Analogue justification

No data on the acute oral toxicity of octadecanoic acid, C16-20-branched alkyl esters (CAS 85203-92-5) are available. The assessment of acute toxicity was therefore based on studies conducted with 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).

Acute oral toxicity

CAS 72576-80-8

The potential acute oral toxicity of hexadecanoic acid, isooctadecyl ester (CAS 72576-80-8) was assessed in a study performed according to OECD 401 (key study, 1999). 5 rats/sex were administered 2000 mg/kg bw of the test substance by gavage. No mortality occurred. No clinical signs were observed during the 14-day observation period and the body weights were comparable between the control group and treatment group. A gross pathology examination was not performed. Based on the results of the conducted study, the oral LD50 is considered to be > 2000 mg/kg bw.

CAS 3234-85-3

An acute oral toxicity study was performed according to a protocol similar to OECD 401, and reported in a summary with limited information (supporting study, 1976). 5 rats/sex/dose were administered 5000 mg/kg bw tetradecanoic acid, tetradecyl ester (CAS 3234-85-3) as a 50% solution in corn oil by gavage. One male died on Day 4; however, no information regarding the cause of death was reported. No clinical signs were observed in the remaining animals during the 14-day observation period and the body weight gain was within the expected range for this strain and study type. No unusual findings were reported during the macroscopic examination. The oral LD50 is considered to be > 5000 mg/kg bw.

CAS 95912-86-0

In a non-guideline study, 5 female mice were administered 5000 mg/kg bw fatty acids, C8-10, C12-18 alkyl esters (CAS 95912-86-0) via the oral route (supporting study, 1991). The study report contained limited information. No mortality occurred and no clinical signs were recorded during the 6-day observation period. There were no effects on body weight. The oral LD50 is considered to be > 5000 mg/kg bw.

Overall conclusion for acute toxicity

The reliable data available for the source substances indicate a very low level of acute toxicity via the oral route, as LD50 values were greater than the currently applied limit value. Therefore, as the available data did not identify any hazard for acute toxicity, octadecanoic acid, C16-20-branched alkyl esters is not expected to be hazardous following acute oral exposure.

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 octadecanoic acid, C16-20-branched alkyl esters (CAS 85203-92-5), data will be generated from information available 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 analogue read-across approach, the available data on acute oral toxicity do not meet the classification criteria according to Regulation (EC) 1272/2008, and are therefore conclusive but not sufficient for classification.