Isooctadecyl isooctadecanoate

Endpoint summary

Description of key information

Oral (OECD 401), rat: LD50 > 2000 mg/kg bw 
Inhalation (OECD 436), rat: LC50 > 5.7 mg/L air 
Dermal (OECD 402), rabbit: 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 adequate, reliable (Klimisch score 2) and consistent studies, and is thus sufficient to fulfil the standard information requirements set out in Annex VII, 8.5, of Regulation (EC) No 1907/2006.

Acute toxicity: via inhalation 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) from a reference substance with similar structure and intrinsic properties. Read-across is justified based on common functional groups, common precursors/breakdown products and similarities in physicochemical and toxicological properties (refer to endpoint discussion for further details). The selected study is thus sufficient to fulfil the standard information requirements set out in Annex VIII, 8.5, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006.

Acute toxicity: via dermal 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) from a reference substance with similar structure and intrinsic properties. Read-across is justified based on common functional groups, common precursors/breakdown products and similarities in physicochemical and toxicological properties (refer to endpoint discussion for further details). The selected study is thus sufficient to fulfil the standard information requirements set out in Annex VIII, 8.5, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006.

Additional information

Justification for read-across

There are no data available on the acute inhalation and dermal toxicity of isooctadecyl isooctadecanoate (CAS 41669-30-1). In order to fulfil the standard information requirements set out in Annex VIII, 8.5, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006, read-across from structurally related substances was conducted.

In accordance with Article 13 (1) of Regulation (EC) No 1907/2006, "information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI are met.” In particular for human toxicity, information shall be generated whenever possible by means other than vertebrate animal tests, which includes the use of information from structurally related substances (grouping or read-across to avoid the need to test every substance for every endpoint).

 

Overview of acute toxicity

 

CAS	Chemical name	Molecular weight	Acute toxicity: Oral	Acute toxicity: Inhalation	Acute toxicity: Dermal
41699-30-1	isooctadecyl isooctadecanoate	536.95	Experimental result: LD50 >2000 mg/kg bw	RA: CAS 26399-02-0	RA: CAS 93803-87-3
26399-02-0	2-ethylhexyl oleate	394.67	Experimental result: LD50 >5000 mg/kg bw	Experimental result: LC50 >5.7 mg/L air	--
93803-87-3	2-octyldodecyl isooctadecanoate	565.01	--	RA: CAS 26399-02-0	Experimental result: LD50 >2000 mg/kg bw

The above mentioned substances are considered to be similar to each other based on structurally similar properties and/or activities. Therefore, the available data on the source substances has been read-across to isooctadecyl isooctadecanoate (CAS 41669-30-1). The target substance is characterized by a branched C18 fatty acid esterified with an aliphatic, but branched C16 and C18 alcohol. Both source substances are structurally very similar to the target substance. They are characterised by isostearic acid esterified with a branched alcohol (2-octyldocdecanol) and oleic acid esterified with 2-ethylhexylanol, respectively. A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13).

 

Discussion

Acute oral toxicity

CAS 41669-30-1

An acute oral toxicity study with the registered substance was investigated in male and female Sprague-Dawley rats according to OECD TG 401 and in compliance with GLP (Saboureau, D.,1989). The neat test substance was administered by gavage to groups of 5 animals per sex at a limit dose of 2000 mg/kg bw. No mortalities and no clinical signs were observed up to the end of the 14-day observation period. Body weights were not affected by treatment with the test substance. The necropsy examination did not reveal any substance-related findings. Based on the results, the oral LD50 value for male and female rats was determined to be greater than 2000 mg/kg bw. A further supporting acute oral toxicity study is also available (Dufour, Ph.,1991). 5 female NMRI EOPS mice received single oral doses of 5000 mg/kg bw of the registered substance. No mortalities were observed during the 6-day study period. No signs of clinical toxicity were reported. The animals showed the expected gain in body weight. The acute oral LD50 in mice was considered to be > 5000 mg/kg bw.

  

 

Acute inhalation toxicity

CAS 26399-02-0

An acute inhalation study was performed with 2-ethylhexyl oleate (CAS No. 26399-02-0) according to OECD TG 436 and incompliance with GLP, in 3 male and 3 female Crl:WI(Han) rats (van Huygevoort, 2010). The animals were exposed to an analytical concentration of 5.7 mg/L of the test substance for 4 hours nose only in an exposure chamber based on the flow past nose-only inhalation chamber (Am. Ind. Hyg Assoc. J. 44(12): 923-928, 1983). An aerosol was generated by nebulization of the test substance by means of a nebulizer (type 950, Hospitak Inc.). No mortalities were reported during the exposure or within the 14 days observation period. Hunched posture was shown by all animals on Day 2 after exposure. No clinical signs were noted during exposure. Additionally body weight gain in males and females was within the range expected for rats of this strain and age used in this type of study. No abnormalities were found at macroscopic post-mortem examination of the animals. The inhalatory 4 hour LC50 value of 2-ethylhexyl oleate aerosol in Wistar rats was found to exceed 5.7 mg/L.

 

Acute dermal toxicity

CAS 93803-87-3

 

The acute dermal toxicity potential of 2-octyldodecyl isooctadecanoate (CAS 93803-87-3) was assessed in a study (limit test) performed according to a protocol similar to OECD TG 402 (Busschers, 1998). 2000 mg/kg bw of the test substance was applied to the skin of 5 Wistar rats/sex under an occlusive dressing for 24 hours. No mortality occurred. No toxicologically relevant clinical signs were noted during the 14-day observation period. The body weight increases were within the range expected for rats used in this type of study and no treatment-related findings were reported during the necropsy and histopathological examination. The LD50 is considered to be > 2000 mg/kg bw.

Conclusions for acute toxicity

Based on read-across and substance-specific data, sufficient evidence is available to conclude that the substance isooctadecyl isooctadecanoate(CAS 41669-30-1) has no hazard for acute toxicity.

Justification for selection of acute toxicity – oral endpoint
The selected study is the most adequate and reliable study based on overall quality assessment (refer to the endpoint discussion for further details).

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

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

Justification for classification or non-classification

Based on substance-specific studies and read-across from structurally similar substances, the available data on the acute toxicity do not meet the classification criteria according to Regulation (EC) 1272/2008 or Directive 67/548/EEC, and are therefore conclusive but not sufficient for classification.