Iron manganese trioxide

Toxicity to soil macroorganisms except arthropods

Link to relevant study record(s)

Reference

Endpoint:

toxicity to soil macroorganisms except arthropods: long-term

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

No data are available on the effects of iron oxides on terrestrial organisms. Iron is ubiquitous in the environment. It comprises some 5 % of the earth's crust (Roempp, 2007). Iron oxides are widespread in soils (Paul and Huang, 1986). Iron occurs mostly in the form of its oxides. The predominant iron mineral in soils is goethite (alpha-FeOOH) (EPA, 2003), the most important iron ores are magnetite (Fe3O4) and hematite (alpha-Fe2O3) (Roempp, 2007).

The interstitial water of the soil is in contact with natural iron oxide minerals. Its concentrations of iron-, manganese-, and zinc ions depend on several environmental factors e.g. duration of contact, temperature, and presence of humic substances and natural complexons e.g. siderophores (Estep, Armstrong , and van Baalen, 1975; Schachtschabel et al., 1992; Rue and Bruland, 1995; Kraemer, 2004). Input of iron oxides pigments will not increase the "saturation" concentrations, and it is very unlikely that synthetic pigments have any significant effect on ion contents in soil water or on other soil properties. On the other hand, if the iron oxides would increase the soil content of iron-, manganese-, and zinc ions, this would be a fertilizing effect in line with the purpose of sewage sludge application on agricultural land.

Performing of a test is scientifically not necessary, as the category members are inert inorganic oxides of iron which resemble naturally occurring iron oxides. Even under worst case conditions an inhibitory effect of synthetic iron oxide pigments is not likely to be exerted on soil organisms.