Appropriateness to set a group health-based guidance value for fumonisins and their modified forms

Abstract

The EFSA Panel on Contaminants in the Food Chain (CONTAM) established a tolerable daily intake (TDI) for fumonisin B 1 (FB 1 ) of 1.0 μg/kg body weight (bw) per day based on increased incidence of megalocytic hepatocytes found in a chronic study with mice. The CONTAM Panel considered the limited data available on toxicity and mode of action and structural similarities of FB 2–6 and found it appropriate to include FB 2 , FB 3 and FB 4 in a group TDI with FB 1 . Modified forms of FBs are phase I and phase II metabolites formed in fungi, infested plants or farm animals. Modified forms also arise from food or feed processing, and include covalent adducts with matrix constituents. Non-covalently bound forms are not considered as modified forms. Modified forms of FBs identified are hydrolysed FB 1–4 (HFB 1–4 ), partially hydrolysed FB 1–2 (pHFB 1–2 ), N-(carboxymethyl)-FB 1–3 (NCM-FB 1–3 ), N-(1-deoxy-d-fructos-1-yl)-FB 1 (NDF-FB 1 ), O-fatty acyl FB 1 , N-fatty acyl FB 1 and N-palmitoyl-HFB 1 . HFB 1 , pHFB 1 , NCM-FB 1 and NDF-FB 1 show a similar toxicological profile but are less potent than FB 1 . Although in vitro data shows that N-fatty acyl FBs are more toxic in vitro than FB 1 , no in vivo data were available for N-fatty acyl FBs and O-fatty acyl FBs. The CONTAM Panel concluded that it was not appropriate to include modified FBs in the group TDI for FB 1–4 . The uncertainty associated with the present assessment is high, but could be reduced provided more data are made available on occurrence, toxicokinetics and toxicity of FB 2–6 and modified forms of FB 1–4 .