Scientific Opinion on the safety and efficacy of bentonite (dioctahedral montmorillonite) as feed additive for all species

Technological additive, mycotoxin binder, bentonite, montmorillonite, aflatoxin, mycotoxins, safety, efficacy
First published in the EFSA Journal
18. Februar 2011
2. Februar 2011
Scientific Opinion


Bentonite (dioctahedral montmorillonite) is an additive proposed to be authorised as a substance for the reduction of the contamination of feed by mycotoxins for all animal species at a recommended use level ranging from 0.05 and 0.3 % in complete feed. The FEEDAP Panel considers 0.5 % bentonite as safe for all target animal species. Since (i) bentonite is authorised as food additive without any restriction, (ii) natural montmorillonite is not genotoxic, and (iii) a 28-week toxicity study in rats showed dietary levels up to 2 % calcium montmorillonite without toxicity, the FEEDAP Panel considers that there is no safety concern for consumers. Bentonite is not irritant to skin and mildly irritant to eyes. Bentonite airborne dust is associated with elevated susceptibility to pulmonary infections. Bentonite is ubiquitous in the environment and is not expected to adversely affect the environment. In vitro systems demonstrated the ability of bentonite to adsorb aflatoxins in aqueous media at different pH values and to a lower degree in gastric juice. Since in vitro systems do not completely mimic the complex situations during digestion, an efficacy assessment requires a minimum of in vivo data. Two in vivo studies in dairy cows (< 5 µg AfB1/kg feed) demonstrated a significant reduction in AfB1 excretion via milk by 0.03–1 % bentonite. The FEEDAP Panel concluded that the bentonite under application has the potential to be efficacious as aflatoxin binder in feed of dairy cows, and extended this conclusion to all ruminants. The Panel was not in a position to assess the efficacy of the bentonite under application as aflatoxin binder for any other animal species than ruminants due to the absence of data.

Panel members at the time of adoption

Gabriele Aquilina, Georges Bories, Paul Brantom, Andrew Chesson, Pier Sandro Cocconcelli, Joop de Knecht, Noël Albert Dierick, Mikolaj Antoni Gralak, Jürgen Gropp, Ingrid Halle, Reinhard Kroker, Lubomir Leng, Anne-Katrine Lundebye Haldorsen, Alberto Mantovani, Miklós Mézes, Derek Renshaw and Maria Saarela
Panel on Additives and Products or Substances used in Animal Feed
EFSA Journal 2011;9(2):2007
Question Number
On request from
European Commission