2-ethylhexanoic acid, cerium salt

Endpoint summary

Description of key information

No acute toxicity studies with 2-ethylhexanoic acid, cerium salt are available, thus the acute toxicity will be addressed with existing data on the dissociation products cerium and 2-ethylhexanoate.

Signs of acute toxicity are not expected for 2-ethylhexanoic acid, cerium salt, since the two moieties cerium and 2-ethylhexanoic acid have not shown signs of acute oral or acute dermal toxicity in experimental testing (both LD50 > 2000mg/kg).

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Additional information

Cerium

The acute oral toxicity of cerium chloride was assessed in an OECD 401 study conducted in Sprague Dawley rats. Cerium chloride was solved in water and dose levels of 2500 mg/kg and 3500 mg/kg were administered via gavage to five animals per sex and dose. All animals were observed for 14 days and necropsy was performed as final examination. 3 animals of the 2500 mg/kg dose level died after 2 days and 9 animals of the 3500 mg/kg dose level died after 3 days. The acute oral, single dose LD50 calculated by Probit Analysis was 2800 mg cerium chloride per kilogram body weight (corresponding to 1600 mg Ce/kg body weight) with 95% confidence limits of 2360 and 3320 mg/kg. Based on the criteria of the CLP Regulation, the substance CeCl₃ should not be classified for acute oral toxicity as the LD50 value is > 2000 mg/kg.

Bradshaw (2013) investigated the acute dermal toxicity of the cerium trinitrate in Wistar rats. Initially, two animals (one male and one female) were given a single, 24 hour, semi-occluded dermal application of the test item to intact skin at a dose level of 2000 mg/kg body weight (expressed as cerium trinitrate). Based on the results of the initial test, a further group of eight animals (four males and four females) was similarly treated. Clinical signs and body weight development were monitored during the study. All animals were subjected to gross necropsy. There were neither deaths nor signs of systemic toxicity. Signs of dermal irritation noted at the test site of one female were very slight erythema, slight desquamation and small superficial scattered scabs. There were no signs of dermal irritation noted in the remaining animals. Animals showed expected gains in bodyweight over the study period except for one female which showed body weight loss during the first week but expected gain in body weight during the second week. No abnormalities were noted at necropsy. The acute dermal median lethal dose (LD50) of the test item in the Wistar strain rat was found to be greater than 2000 mg/kg body weight (corresponding to 860 mg Ce/kg body weight).

 

2-ethylhexanoate

In an acute oral toxicity study 4 rats/sex/dose were dosed with 90, 722, 1445 or 2890 mg/kg bw. No mortality was observed in the 90, 722 and 1445 mg/kg bw dose groups. The test material caused mortality in rats administered a dose of 2890 mg/kg bw (4/4), and transitory weakness at lower doses in a dose-dependent manner. The LD50 was calculated to 2043 mg/kg bw.

In another acute oral toxicity study 5 rats/sex/dose have been administered 0.2, 1.6, 3.2 and 4.0 ml 2-ethylhexanoic acid/ kg bw. No substance related clinical signs nor mortality was observed at 0.2 and 1.6 ml/kg. However, 1/10 animals died. After administration of 3.2 ml/kg and 4 ml/kg apathy dyspnea abdominal position and re crusted eyes and snouts were observed. Mortality in these dose groups was 3/10, 5/10, respectively. LD 50 was estimated to be 4 mL/kg bw, being equivalent to 3640 mg/kg bw (density 0.91 g/ml). This result is supported by another study which however was poorly documented.

Dermal toxicity of 2 ethylhexanoic acid was tested in an OECD 402 guideline study. Five Wistar rats/sex/dose have been exposed dermally (semi-occlusive to a limit dose of 2000 mg/kg bw 2-ethylhexanoic acid. No mortality and no clinical symptoms beside eschar formation have been observed. LD50 dermal therefore is > 2000 mg/kg bw.

2-ethylhexanoic acid, cerium salt

Signs of acute toxicity are not expected for 2-ethylhexanoic acid, cerium salt, since the two assessment entities cerium and 2-ethylhexanoic acid have not shown signs of acute oral or dermal toxicity in experimental testing (both LD50 > 2000mg/kg). Under the assumption that the moieties of 2-ethylhexanoic acid, cerium salt show their toxicological profile individually upon dissolution, the acute oral (systemic) toxicity of 2-ethylhexanoic acid, cerium salt can be calculated using the equation given in regulation (EC) 1272/2008, Annex I, Section 3.1.3.6.1.

A study for acute toxicity via inhalation was not conducted with 2-ethylhexanoic acid, cerium salt, since it is produced and placed on the market in a form in which no inhalation hazard is anticipated, thus acute toxic effects are not likely to occur during manufacture and handling of that substance. For further information on the toxicity of the individual moieties, please refer to the relevant section in the IUCLID.

 

The calculated oral and dermal LD50 for 2-ethylhexanoic acid, cerium salt is > 2000mg/kg, hence the substance is not to be classified according to regulation (EC) 1272/2008 for acute oral toxicity as well as for specific target organ toxicity, single exposure (STOT-SE, oral).

Justification for classification or non-classification

Based on in vivo oral and dermal LD50 data on the moieties, acute toxicity estimates for 2-ethylhexanoic acid, cerium salt have been calculated resulting in LD50 values > 2000 mg/kg bw.

According to the criteria of REGULATION (EC) No 1272/2008 and its subsequent adaptions, 2-ethylhexanoic acid, cerium salt does neither have to be classified and has no obligatory labelling requirement for acute oral toxicity nor for specific target organ toxicity after single exposure (STOT SE).