Following a Rapid Alert System for Food and Feed (RASFF) notification concerning the use of an unauthorised irradiated colouring agent (brown iron oxide) as coatings of food supplements, the European Commission asked EFSA to assess the scientific validity and robustness of three documents i) two safety assessments from two pharmaceutical companies including information on the manufacturing process of iron oxides, and ii) one safety assessment on gamma irradiated iron oxides in food supplements provided by a consultant. According to the supplier of iron oxides and hydroxides (E 172), the aim of the irradiation treatment (60Co-gamma irradiation) was to eliminate microbiological contamination in the product.
The food additive iron oxides and hydroxides (E 172) include red iron oxide (Fe2O3), yellow iron oxide (FeO(OH)), black iron oxide (FeO·Fe2O3) and brown iron oxide (a mixture of the former oxides). Each iron oxide has different physical and chemical properties and they can be used separately or as a mixture (brown iron oxide).
Iron oxides and hydroxides (E 172) are authorised food additives in the EU in entire fresh fruit and vegetables with a maximum permitted level of 6 mg/kg and according to quantum satisin 48 food categories (Regulation (EC) No 1333/2008). Within these food categories, iron oxides and hydroxides are authorised in food supplements supplied in a liquid form, food supplements supplied in a syrup-type or chewable form and food supplements supplied in a solid form including capsules and tablets and similar forms, excluding chewable forms.
The three safety assessments submitted to EFSA can only be considered a hazard identification as no hazard characterisation (characterisation of the biological and toxicological dose-response relationships), no exposure assessment and no risk characterisation was included in these documents.
EFSA noted that the gamma irradiation of iron oxides (yellow, red, black and brown) has not been previously evaluated by other Scientific Committees dealing with foodstuffs, pharmaceutical products or cosmetics.
EFSA noted that the maximum irradiation doses (15-37 kGy) applied to iron oxides used as food additives are approximately two times higher than the maximum doses currently authorised in the EU for “other food and food ingredients”.
EFSA also noted that some evidence is available in the scientific literature demonstrating a reduction of iron(III) to iron(II) due to 60Co-gamma irradiation and, that the food additive black iron oxide, as authorised in the EU, contains iron in both (II) and (III) valence states. Therefore, an increase in the content of divalent iron would not be of safety concern per se. However, EFSA also notes that the information on irradiated iron oxides provided is very limited and insufficient to substantiate the claim that iron oxides are not expected to undergo any chemical transformation upon irradiation. In order to demonstrate the chemical stability of iron oxide during the 60Co-gamma irradiation treatment, EFSA recommends to carry out some further analyses.
Overall, addressing the term of reference and the documents provided by the European Commission, EFSA concluded that the provided information is insufficient to fully substantiate the conclusion drawn from the provided safety assessments.