Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of zeolites (≥ 50%) obtained from Neapolitan Yellow Tufa as a technological additive (functional group: anticaking) for all animal species. The additive is specified to contain not less than 50% of zeolites, namely phillipsite, chabazite and analcime. Neapolitan Yellow Tufa originates from the volcanic activity of Campi Flegrei, Italy. According to the conventional risk assessment, due to a lack of adequate data, the safety of the additive 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, of concern for the consumer. The additive poses a risk by inhalation. It is not irritant to the skin. The Panel cannot conclude on the eye irritancy and on the dermal and respiratory sensitisation potential of the additive. 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 for the target species, the consumer and the user could not be assessed. The additive is safe for the environment. The additive is considered to be efficacious in feedingstuffs for all animal species at 20,000 mg/kg complete feed.