9-Octadecenedioic acid

Endpoint summary

Description of key information

Oral: LD50 > 2000 mg/kg bw 

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

The available information comprises an adequate and reliable study (Klimisch score 2 due to read-across) from a reference substance with similar structure and intrinsic properties. Read-across is justified based on a similar structure for which the presence of either a cis- or a trans-double bond of the C-chain is the only difference in the molecular structure (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

Justification for read-across

There are no data available on the acute oral toxicity of octadec-9-enedioic acid (EC 802-22-7). The assessment was therefore based on a study conducted with the analogue substance (Z)-9-Octadecen-1,18-dioic acid (CAS 20701-68-2) 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 structurally closest to the target substance is 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. Based on their chemical structure, both the target substance (Octadec-9-enedioic acid, EC 802-22-7) and the source substance ((Z)-9-Octadecen-1,18-dioic acid, CAS 20701-68-2), belong to the family of linear monounsaturated dicarboxylic acids. While the target substance contains a cis- and trans-isomer, the source substance consists of the cis-isomer. A detailed justification for the analogue read-across approach is provided in the technical dossier (see IUCLID Section 13).

 

Acute oral toxicity

CAS 20701-68-2

The acute oral toxicity of (Z)-9-octadecen-1,18-dioic acid, was assessed in a study performed according to OECD guideline 401 and under GLP conditions (Pels Rijcken, 1996). 5 Wistar rats/sex were exposed to a limit dose of 2000 mg/kg bw. There was no mortality. No clinical signs were observed up to the end of the 14-day observation period. All the animals showed the expected gain in body weight during the study and necropsy revealed no substance-related findings. Based on the results, the oral LD50 value for Wistar rats is > 2000 mg/kg bw.

Based on the read across approach, the target substance is not considered to exhibit toxic properties after acute exposure.

Justification for selection of acute toxicity – oral endpoint
Hazard assessment is conducted by means of read-across from a structural analogue. The selected study is the most adequate and reliable based on the identified similarities in structure and intrinsic properties between the source and target substance and overall quality assessment (refer to the endpoint discussion for further details).

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 Octadec-9-enedioic acid (EC 802-122-7), 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.