Scientific Opinion on the safety and efficacy of bentonite as a technological feed additive for all species

Technological additive, anti-caking agent, binder, substances for control of radionuclide contamination, bentonite, safety, efficacy
First published in the EFSA Journal
20 July 2012
14 June 2012
Last Updated
26 October 2017. This version replaces the previous one/s.
Scientific Opinion

Bentonites are colloidal clays composed largely of montmorillonite. They are currently authorised for use as feed additives (binders, anti-caking agents and coagulants) to a maximum of 20 g/kg feedingstuffs. They are also authorised for use as food additives. A consortium is seeking the re-authorisation of bentonites as pellet binders and anti-caking agents and authorisation for a new application for the control of radionuclide contamination. Chickens and piglets tolerated the addition of bentonite at a concentration of 3 % of diet and dairy cows tolerated 2 % added bentonite. Trout are reported to tolerate at least 2.5 % bentonite in the diet. Since the application is for all animal species and all bentonites, and as a margin of safety is difficult to establish, the FEEDAP Panel considers that the presently authorised limit of 2 % of diet should be retained. Addition of bentonites to diets is incompatible with the use of robenidine and is expected to reduce the effectiveness of other coccidiostats. No concerns for the safety of consumers of food products derived from animals fed diets containing bentonite were identified. Bentonites are not skin irritants but may be mildly irritant to the eye. Although skin sensitisation was not considered, the Panel notes that bentonites are used in cosmetics. The Panel considers it prudent to assume that all bentonite dusts pose a hazard to those handling the additive. Bentonites are ubiquitous soil components, and their use in animal production is not expected to adversely affect the environment. Bentonites can increase pellet durability when added to complete feed at concentrations of between 1 % and 2 %. Since bentonites are authorised for use, without restriction, as anti-caking agents in food and can be assumed to demonstrate similar properties when applied to feed materials, no further demonstration of efficacy is considered necessary. Bentonites added to feed contaminated by radioactive fallout or made available to grazing animals will reduce levels of radiocaesium in animals and their products.

Panel members at the time of adoption
Gabriele Aquilina, Georges Bories, Andrew Chesson, Pier Sandro Cocconcelli, Joop de Knecht, Noël Albert Dierick, Mikolaj Antoni Gralak, Jürgen Gropp, Ingrid Halle, Christer Hogstrand, the late Reinhard Kroker, Lubomir Leng, Secundino López Puente, Anne-Katrine Lundebye Haldorsen, Alberto Mantovani, Giovanna Martelli, Miklós Mézes, Derek Renshaw, Maria Saarela, Kristen Sejrsen and Johannes Westendorf
Panel on Additives and Products or Substances used in Animal Feed
EFSA Journal 2012;10(7):2787
Question Number
On request from
European Commission