Cerium trichloride

Endpoint summary

Description of key information

Skin irritation:
Five studies are available with cerium trichloride and are used in a weight of evidence approach: one K1 determination of the pH (Krivograd, 2012), one K1 in vitro skin corrosion study (Warren, 2013b) performed according to OECD guideline 431 and EU method B40, one K1 in vitro skin irritation study (Warren, 2013a) performed according to OECD guideline 439 and EU method B46, one K2 in vivo acute dermal irritation study with rabbits performed according to Federal Guideline 16 CFR 1500.41 (Shapiro, 1990) and one in vivo acute dermal irritation study with rabbits (K 1 study; Bradshaw, 2013) performed according to OECD 404 guideline and EU method B4 and under GLP conditions. After appraisal of the evidence it is concluded that the substance is corrosive to the skin.
Eye irritation:
As the substance is considered to be corrosive to the skin, the adverse effect on eyes is implicit. Therefore no eye irritation test is performed according to REACH Annex VIII section 8.2.1, column 2.

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (corrosive)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin irritation / corrosion

First, the pH was measured electrochemically with a calibrated pH meter at 20 ± 1°C (Krivograd, 2012) in order to evaluate the irritant or corrosive potential of cerium trichloride. The obtained pH-value was the basis for deciding if it was necessary to determine the acid reserve. A 10% solution of the test item was prepared by stirring 10 g sample material with 90 g H2O dem. (Milli-Q water - Type 1 water grade) for 30 minutes and then adjusting it to a temperature of 20°C. Prior to the measurement, the pH-meter was calibrated via a 3-point calibration. The pH was determined 3 times from the 10% solution of the test item under continuous stirring. The measured pH was protocolled. As the pH value was determined to be 4.58, a determination of the acid reserve was not applicable.

An in vitro skin corrosion (Warren, 2013a) and an in vitro skin irritation (Warren, 2013b) test were performed according to OECD 431and EU method B40 and OECD guideline 439 and EU Method B46, respectively. On the basis of the relative mean viability of the treated tissues, the test item was considered to be non-irritating and non-corrosive to the skin.

An in vivo study in rabbits (Shapiro, 1990) was available. The study was performed according to Federal Guideline 16 CFR 1500.41. This study, using a 24-hour exposure period and using an occlusive dressing, is considered to represent a worst-case scenario. The study concluded to a corrosive effect of cerium trichloride. The reversibility of the observed effects was not studied since the study was stopped after 72 hours of observation.

An in vivo acute dermal irritation study in rabbits was performed according to OECD guideline 404 and EU Method B4 (Bradshaw, 2013). In this test, the substance was applied in a semi-occlusive dressing at three locations on the back of a single rabbit for 3 min, 1 hour and 4 hours of exposure, respectively. Both the 3 min and 1 hour exposure did not produce evidence of skin irritation. However, a single 4 hour application produced well-defined erythema, slight oedema and grey/green colored dermal necrosis. The skin reactions noted were considered to be irreversible and indicative of full thickness tissue destruction.

After appraisal of the evidence it is concluded that the substance is corrosive to the skin.

Eye irritation

As the substance is considered to be corrosive to the skin, hazardous effect on eyes is implicit. Therefore, no eye irritation test is performed according to REACH Annex VIII section 8.2.1, column 2.

Justification for selection of skin irritation / corrosion endpoint:
No study selected as a weight of evidence approach is used.

Justification for selection of eye irritation endpoint:
No further testing needed, as the substance is considered corrosive to skin.

Effects on skin irritation/corrosion: corrosive

Effects on eye irritation: corrosive

Justification for classification or non-classification

In an in vivo acute dermal irritation study in rabbits, a single 4 hour application produced well-defined erythema, slight oedema and grey/green colored dermal necrosis. The skin reactions noted were considered to be irreversible and indicative of full thickness tissue destruction. The test item was classified as corrosive category 1C (H314: causes severe skin burns and eye damage) according to the criteria of the CLP Regulation EC No 1272/2008.

No further testing was performed related to eye irritation. It should be noted that if a substance or mixture is classified as Skin corrosive Category 1 then serious damage to eyes is implicit. Therefore, the substance is directly classified as serious eye damage 1 (H318: causes serious eye damage) according to the CLP Regulation.