Registration Dossier
Registration Dossier
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EC number: 242-637-9 | CAS number: 18868-43-4
Endpoint summary
Administrative data
Description of key information
Key value for chemical safety assessment
Skin sensitisation
Endpoint conclusion
- Endpoint conclusion:
- no adverse effect observed (not sensitising)
- Additional information:
The substance is not considered to have sensitising properties, based on reliable in vivo skin sensitisation studies in guinea pigs with the substance and/or with suitable surrogate substances (read-across): the moderately to very soluble molybdenum substance sodium molybdate, ammonium dimolybdate, molybdenum trioxide and roasted molybdenite concentrate did not show any sensitising effects in reliable guinea pig maximisation studies. The inert substance MoS2 also was not sensitising.
To avoid unnecessary (animal) testing, a comprehensive grouping and read-across concept has been developed amongst several molybdenum containing substances. This grouping/category approach is described in detail in a separate report, in accordance with the ECHA's "Read-Across Assessment Framework" (RAAF). This document is attached to section 13 in the technical dosser and to the CSR.
The main conclusion is that read-across/grouping of molybdenum substances is justified for systemic effects, including sensitisation, based on the formation of the molybdate ion from all substances in the category, as the driver for any toxicity. The non-molybdenum moieties in the substances, such as iron, ammonium, calcium or sodium do not contribute to toxicity, or at least to a lesser extent than the molybdenum moiety. The substances for which skin sensitisation studies are available are moderately to very soluble and represent worst-case surrogates for less soluble molybdenum substances. For details, see “read-across document” in IUCLID section 13.
In conclusion, the registered substance is not considered to have sensitising properties, and no hazard classification is required for sensitisation.
Justification for classification or non-classification
The substance is not considered to have sensitising properties, based on reliable in vivo skin sensitisation studies in guinea pigs with the substance and/or with suitable surrogate substances (read-across): the moderately to very soluble molybdenum substance sodium molybdate, ammonium dimolybdate, molybdenum trioxide and roasted molybdenite concentrate did not show any sensitising effects in reliable guinea pig maximisation studies. The inert substance MoS2 also was not sensitising.
To avoid unnecessary (animal) testing, a comprehensive grouping and read-across concept has been developed amongst several molybdenum containing substances. This grouping/category approach is described in detail in a separate report, in accordance with the ECHA's "Read-Across Assessment Framework" (RAAF). This document is attached to section 13 in the technical dosser and to the CSR.
The main conclusion is that read-across/grouping of molybdenum substances is justified for systemic effects, including sensitisation, based on the formation of the molybdate ion from all substances in the category, as the driver for any toxicity. The non-molybdenum moieties in the substances, such as iron, ammonium, calcium or sodium do not contribute to toxicity, or at least to a lesser extent than the molybdenum moiety. The substances for which skin sensitisation studies are available are moderately to very soluble and represent worst-case surrogates for less soluble molybdenum substances. For details, see “read-across document” in IUCLID section 13.
In conclusion, the registered substance is not considered to have sensitising properties, and no hazard classification is required for sensitisation.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
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