Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of Kieselguhr (diatomaceous earth, three forms: natural, purified calcined and purified flux‐calcined) as a technological additive (functional group: anticaking and binder) for all animal species. Kieselguhr is predominantly amorphous silica (non‐crystalline silicon dioxide (SiO2)). Based on the information submitted, Kieselguhr natural, purified calcined and purified flux‐calcined are safe when used at 5000 mg/kg of complete feed in all terrestrial animals. No conclusions can be reached on the safety of its use in aquatic animals. The use of Kieselguhr natural, purified calcined and purified flux‐calcined in animal nutrition under the proposed conditions of use is safe for the consumer and the environment. Kieselguhr natural and purified flux‐calcined are not irritant to the skin. All the three forms of the additive are irritant to the eyes and should be considered dermal and respiratory sensitisers. Any exposure is considered a risk. The FEEDAP Panel concluded that the additive is effective as a pellet binder. Kieselguhr is efficacious as an anticaking agent at a minimum concentration of 15,000 mg/kg.
