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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Link to relevant study record(s)

Description of key information

The substance pNMC hydroxide is a dark grey powder, with melting point in excess of 360°C. Most of the material is in the form of large particles, withthe majority of particles below 20 µm (D90 of 13.2 µm).

Only limited amount of toxiclogical information is available on pNMC hydroxide. The substance is essentially non-toxic when given as a single dose (oral) to rat, is neither a skin irritant nor a skin sensitiser. It is also negative in two genotoxicity tests

No chronic or sub-chronic mammalian studies have been performed on pNMC hydroxide. The potential adverse effects of such exposures are therefore based on the known toxicological profiles of the main constituents of this iUVCB, i.e. Cobalt and Nickel (hydroxide).

The National Toxicology Program Technical Report on the toxicity and carcinogenesis studies of cobalt sulphate heptahydrate (CAS no 10026-24-1) in F344/N rats and B6C3F1 mice (inhalation studies) (NTP TR471, August 1998) states that “'Krasovskii and Fridyland (1971) administered 0.5 or 2.5 mg/kg cobalt by gavage to rats six times per week for 7 months. These investigators found polycythemia and a suppression of leucocyte function”.



When ingested in sufficient amounts, adverse effects may be observed. Bioelution tests demonstrated that the metal release in gastric fluid was approximately between 10-50%, and 100% in lysosomal fluids.



The substance is a complex insoluble mixed metalhydroxide. It is unlikely to be absorbed unchanged. It is likely that, if absorbed, the substance is not distributed widely.



The substance is a complex insoluble mixed metalhydroxide. It is unlikely to be absorbed unchanged. Given that nickel, cobalt and manganese are considered essential elements, absorbed ions are likely to enter appropriate metabolic pools.



Overall, most of the complex will be excreted, unabsorbed, in faeces. Absorbed material (probably as metal ions) will be excreted mainly in urine.


The following information is taken into account for any hazard / risk assessment:

The substance does appear to dissociate to some extent in the acid conditions of the stomach to render some material available for absorption.It is not expected that the solid material will be absorbed following dermal administration, however a dermal absorption value of 1 % is adopted for risk assessment purposes.


Key value for chemical safety assessment

Additional information