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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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 registered substance is corrosive, hence an understanding of its toxicokinentic potential - rate of absorption, systemic availability etc are based on its disintergration products - Mn2+ and Mn4 +.

With regards to Mn, oral absorption is low at approximately 5% ranging from 3 -13% as reported by published lieterature - well controlled homeostatically, dermal absorption rate is minimal while inhalation is considered as 100%/worst-case.

Key value for chemical safety assessment

Bioaccumulation potential:
no bioaccumulation potential
Absorption rate - oral (%):
5
Absorption rate - dermal (%):
1
Absorption rate - inhalation (%):
100

Additional information

Water-soluble (64g/l at 20dec Cel) Potassium permanganate (KMnO4) is a strong oxidant with erratic behaviour that is driven by the physical conditions of the receiving ‘body’ - in this case the stomach – its pH, and even temperature will catalyse multiple reactions resulting into different oxidation states of manganese. The duration of this reaction phase is unknown as it depends on the physical state of the receiving body.

Multiple reaction phases

-      Under acidic conditions (more in-line with oral exposure/HCl stomach acid)

MnO4-+ 4H++ 3e- -> MnO2(s) + 2H2O

MnO4-+ 8H++ 5e- -> Mn2++ 4H2O


-
    Under alkaline conditions, the half-reaction is (CRC, 1990):

MnO4- + 2H2O + 3e- -> MnO2 (s) + 4OH-

-    Under aqueous solution, permanganic acid equilibrates with hydrogen ions in water, (Willhite, CC., 2013):

MnO4-+ 8H++ 5e- -> Mn2++ 4H2O

The insoluble, less bioavailable MnO2forms solids and passes through the GI tract while the Mn2+is systemically available. Ingestion of water soluble manganese salts such as MnCl2or MnSO4induced systemic toxicity at lower doses than ingestion of other insoluble forms such as MnO2(Willhite, CC., 2013). Although several other soluble manganese salts exhibiting Mn2+valency exist, MnCl2is the salt mostly used in research, mainly because of its high bioavailability.

Exposure route also plays an important role on absorption, distribution and elimination for Mn and its inorganic compounds. After reviewing more than 100 publications on Mn and its inorganic compounds, Gwaizdaet al.,(2007) concluded that while systemic bioavailability of inhaled Mn is essentially equivalent to that of intravenous injection (100%), systemic uptake of ingested inorganic Mn (e.g. chloride and oxides) was not more than 3%. The reduced bioavailability from ingested inorganic manganese has been associated to intestinal uptake regulation and hepatic elimination (IEH, 2004;Willhite, CC., 2013). These are the two primary physiological factors that dictate proportional control of systemic bioavailability for Mn and its inorganic compounds.