Iron

Iron is the most abundant mineral in most peat types, present primarily as complexes with humic and fulvic acids rather than as free ions. Iron content varies significantly by peat source and is generally higher in lowland (fen) peat than in raised bog sphagnum peat.

Form in Peat

Iron in peat exists predominantly as Fe²⁺ and Fe³⁺ ions chelated by humic and fulvic acid carboxyl and phenolic groups. This chelation keeps iron bioavailable while preventing the formation of insoluble iron oxides. The humic-iron complex is responsible for much of peat’s dark brown to black coloration.

Cosmetic Relevance

Iron delivery through peat baths may contribute to improved tissue oxygenation and wound healing. However, excessive iron can be pro-oxidant — the chelation by humic acids serves a protective role by controlling iron reactivity. Iron content is also relevant to safety considerations, as very high concentrations could cause skin staining or irritation.