Triiron tetraoxide

Endpoint summary

Additional information

According to Column 2 of Information Requirement 9.3.2., Annex IX, Commission Regulation (EU) 2018/1881, ”The study need not be conducted if: the substance has a low potential for bioaccumulation (for instance a log Kow ≤ 3) and/or a low potential to cross biological membranes…For nanoforms, use of any physicochemical property (e.g. octanol water partition coefficient, dissolution rate, dispersion stability) as a reason for waiving the study shall include adequate justification of its relevance to low potential for bioaccumulation or unlikely direct and indirect exposure of the aquatic compartment.”  A comprehensive assessment clearly indicates that there is no need for testing. The assessment was performed by ARCHE (Assessing Risks of CHEmicals) in 2010 and the results are laid down in the "White Paper on waiving for secondary poisoning for Fe and Al compounds". The following conclusions are presented:

The REACH Regulations stipulate the need to assess the bioaccumulation potential for aquatic organisms in order to be used for hazard classification and PBT assessment as well as to evaluate the potential risk for secondary poisoning. In general, metals do not biomagnify unless they are present as, or have the potential to be, in an organic form, e.g. methylmercury is a classic example. Most inorganic metal compounds are not expected to biomagnify. The weight of evidence for iron supports this observation and allows waiving the need for additional testing for secondary poisoning for the purpose of fulfilling the REACH obligations. Iron is an essential trace element and is well regulated in all living organisms. Differences in iron uptake rates are related to essential needs, varying with the species, size, life stage, seasons etc. Iron homeostatic mechanisms are applicable across species with specific processes being active depending on the species and their life stages. The available evidence shows the absence of iron biomagnification across the tropic chain both in the aquatic and terrestrial food chains. The existing information suggests that iron does not biomagnify, but rather that it tends to exhibit biodilution. Differences in sensitivity among species are not related to the level in the trophic chain but to the capability of internal homeostasis and detoxification.