Registration Dossier

Administrative data

Description of key information

A fully compliant OECD 422 study is available, performed using dicerium tricarbonate as the test substance. Reading-across from this similar substance, the study has been considered as the key study for evaluating the repeated dose toxicity of dineodymium tricarbonate.
Repeat dose studies via the dermal and inhalation routes have been waived.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Endpoint conclusion
Dose descriptor:
NOAEL
450 mg/kg bw/day
Study duration:
subacute
Species:
rat

Additional information

The NOEL of 150 mg/kg bw/day for parental toxicity was set, based on microscopic findings in the stomach likely related to portal-of-entry irritating effects. As haematological and/or clinical chemistry changes were observed only in animals treated at 1000 mg/kg bw/day, and there were no other significant effects, the NOAEL for systemic toxicity was 450 mg/kg bw/day.

In accordance with section 1 of annex XI of the REACH regulation, a repeat dose toxicity study via the dermal route does not need to be conducted if the study does not appear to be scientifically necessary. A study conducted to OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test) already sufficiently addresses the repeat dose toxicity data requirements.

In accordance with section 1 of annex XI of the REACH regulation, a repeat dose toxicity study via the inhalation route does not need to be conducted if the study does not appear to be scientifically necessary. A study conducted to OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test) already sufficiently addresses the repeat dose toxicity data requirements.

Justification for classification or non-classification

Treatment for at least 28 days in males and approximately 5 -6 weeks in females up to and including 1000 mg/kg bw/day by oral gavage was well tolerated, with no mortality, without any signs of over toxicity, and limited effects on body weight/food consumption.

The NOEL of the study for parental toxicity was set at 150 mg/kg bw/day on the basis of microscopic findings in the stomach detected in males at 450 mg/kg bw/day and in animals of both sexes receiving 1000 mg/kg bw/day. It is considered that these effects were likely related to portal-of-entry irritating effects, due to the high concentrations of the substance given as a bolus by gavage.

On this basis the substance is not classified for repeated dose toxicity.