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Toxicological information

Carcinogenicity

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Description of key information

No evidence of carcinogenicity was seen in an NTP study in the rat with the read-across substance manganese (II) sulphate.  Equivocal evidence of carcarcinogenicity was seen in a mouse study, based on a marginally increased incidence of thyroid gland follicular cell adenoma.

Key value for chemical safety assessment

Additional information

High quality NTP studies are available for the read-across substance, manganese (II) sulphate. The substance, sodium permanganate is a strong oxidising agent and will react with organic molecules and in the conditions of the stomach and following contact with skin to produce Mn (II). Read-across is therefore appropriate and justified.

There was no evidence of carcinogenic activity (according to the NTP Levels of Evidence of Carcinogenic Activity) of manganese (II) sulfate monohydrate in male or female rats.

Potassium permanganate has been used as a surrogate for sodium permanganate where data are not available. Read-across from potassium permanganate to sodium permanganate is appropriate from the toxicological point of view as the most toxicologically relevant part of the substances is the same (permanganate). The contribution of the sodium/potassium ions to the toxicity of the respective substances is likely to be minimal. The toxicity of both substances is therefore likely to be very similar and will be dominated by local (site of contact) irritant/corrosive effects and systemic toxicity due to the absorption of manganese ions. This toxicophore similarity is adequate justification for waiving the conduct of specific studies with sodium permanganate and the dossier reflects this waiving proposal by including summaries of read-across studies where appropriate.

There was equivocal evidence of carcinogenic activity (according to the NTP Levels of Evidence of Carcinogenic Activity) of manganese (II) sulfate monohydrate in male and female mice, based on the marginally increased incidences of thyroid gland follicular cell adenoma and the significantly increased incidences of follicular cell hyperplasia.


Carcinogenicity: via oral route (target organ): glandular: thyroids

Justification for classification or non-classification

No classification is proposed. The evidence for carcinogenicity is limited.