Cerium trichloride

Toxicological Summary

Workers - Hazard via inhalation route

Systemic effects

Acute/short term exposure

DNEL related information

Local effects

Acute/short term exposure

DNEL related information

Workers - Hazard via dermal route

Systemic effects

Acute/short term exposure

DNEL related information

Workers - Hazard for the eyes

Local effects

Hazard assessment conclusion:

medium hazard (no threshold derived)

Additional information - workers

Acute / short-term exposure (systemic and local effects)

- No acute data were available for the inhalation route of exposure. In accordance with REACH Annex VIII, this study does not need to be conducted as exposure via inhalation is a less likely than via the dermal route due to the fact that the substance forms clumps and is produced as a solution. In addition, an acute inhalation study does not need to be conducted as the substance is classified as corrosive to the skin (according to REACH Annex VIII section 8.5, column 2).

- No acute data were available for the dermal route of exposure. No further testing is required as the substance is classified as corrosive to skin (category 1C, H314) and corrosive to eyes (Category 1, H318) according to CLP criteria. According to ECHA's Guidance on Information Requirements and Chemical Safety Assessment, Part E, Table E.3-1 the substance should be considered to cause moderate hazard.

Long-term exposure (systemic effects)

- Dermal: No long-term dermal toxicity studies are available for cerium trichloride. Furthermore, as the substance is classified as corrosive to the skin, serious local effects may be expected after repeated dermal exposure to the diluted test item and, for reasons of animal welfare, the test should be avoided. An oral combined repeated dose toxicity study with reproduction/developmental toxicity screening has been performed with the read-across substance cerium trinitrate (Braun, 2013). The No Observed Adverse Effect Level (NOAEL) for systemic effects (parental animals) was considered to be 330 mg/kg bw/day. However this value can not be considered relevant for systemic toxicity after repeated oral exposure as this value was based on local effects rather than systemic effects: the morphological changes in the stomachs were reported to be local effects (irritation after repeated oral gavage) rather than systemic toxicity and the differences in the food consumption/body weight were considered secondary to the changes in the stomach. In addition, it is reported that two animals treated at 1000mg/kg bw/day died as a result of the stomach findings. Thus, no systemic effects related to the repeated oral exposure to the test item were really identified.

In the same study some changes in some reproduction/developmental parameters were also observed at the highest dose of 1000 mg/kg bw/day and the NOEL for reproduction/developmental toxicity was considered to be 330 mg/kg bw/day. However, clear conclusion could not be drawn on this study regarding the possible causes of these changes: a secondary effect resulting from the chemical stress observed in males and pregnant females due to high local irritation observed in the stomach after repeated oral gavage of the compound or a primary effect of the substance). Therefore, these effects could be considered as local effects rather than true systemic effects.

Overall, as only local effects were observed, there are no adequate data for route-to-route extrapolation. Thus, a worker-DNEL long-term for dermal route-systemic effects can not be derived.

- Inhalation:

No long-term inhalation toxicity studies are available for cerium trichloride but an oral combined repeated dose toxicity study with reproduction/developmental toxicity screening (Braun, 2013) exists. As described here above for the DNEL long-term for dermal route-systemic effects, these data are not adequate for route-to-route extrapolation. Therefore a long-term DNEL for workers for inhalation route-systemic effects can not be derived based on this information. Furthermore, as the substance is classified as corrosive to the skin, serious local effects may be expected after repeated inhalation exposure to the diluted test item and, for reasons of animal welfare, further testing should be avoided. In addition, the substance appears as a clump and is produced as a solution. Therefore formation of respirable suspended particulate matter is unlikely.

Long-term exposure (local effects)

- No reliable repeated dose toxicity study was available for this substance via the dermal and inhalation route of exposure. Therefore, a DNEL long-term exposure, local effects cannot be derived for the dermal and inhalation route.

Furthermore, and due to the properties of the substance, cerium trichloride appears as a clump and it is produced as a solution. Therefore formation of and exposure to respirable suspended particulate matter is unlikely.

Regarding DNEL long-term local effect, dermal exposure, although no DNEL can be derived, the substance is corrosive to the skin. Therefore as no reliable dose descriptor can be set for the irritation/corrosion endpoint, a qualitative assessment of the potency of the substance is performed according to ECHA's Guidance on Information Requirements and Chemical Safety Assessment Part E (2012). This assessment indicates that cerium trichloride is of moderate hazard. This hazard band will be used for the development of exposure scenarios with risk management measures and operational conditions for controlling exposures and thereby risks.

General Population - Hazard via inhalation route

Systemic effects

Acute/short term exposure

DNEL related information

Local effects

Acute/short term exposure

DNEL related information

General Population - Hazard via dermal route

Systemic effects

Acute/short term exposure

DNEL related information

General Population - Hazard via oral route

Systemic effects

Acute/short term exposure

DNEL related information

Additional information - General Population

No consumer use is expected. Therefore, no DNEL is derived.