Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of the mixture of Sepiolite and Kieselguhr (diatomaceous earth) (Anpro) as a technological feed additive for all terrestrial animal species. According to the conventional risk assessment, due to lack of adequate data, the safety of the additive Anpro for the target species cannot be established. Based on current knowledge, there is no indication of substantial absorption of the components of the additive and therefore no concern for the consumer. The additive poses a risk by inhalation. It is not irritant to the skin or eyes but should be considered as skin sensitiser. As no suitable data in line with the requirements of the Guidance on risk assessment of nanomaterials were provided by the applicant, the potential risks associated with the presence of nanoparticles could not be assessed for the target species, the consumer and the user. The additive is safe for the environment. The FEEDAP Panel is not in the position to conclude on the efficacy of the additive for all terrestrial animal species.