Deccox®, containing decoquinate as the active substance, is a feed additive intended to be used for the prevention of coccidiosis in chickens for fattening at a dose range of 20-40 mg/kg complete feed. Decoquinate from Deccox® is safe for chickens for fattening at the highest applied concentration in complete feed of 40 mg/kg. No practically relevant interactions with other additives or veterinary drugs exist except with bentonite. Decoquinate does not have antibacterial action. Decoquinate is not genotoxic and not carcinogenic. Deccox® is safe for the consumer under the proposed conditions of use. No withdrawal period is required to ensure consumer safety. No maximum residue limits are considered necessary. The inhalation risk for users is considered negligible since inhalation toxicity and exposure are very low. Deccox® is not an irritant to skin and eyes and has no sensitisation potential. The ratios predicted environmental concentration/predicted no effect concentration (PEC/PNEC) for terrestrial, aquatic compartment and sediment are below 1, indicating that decoquinate used in chickens for fattening up to the highest proposed dose, does not pose a risk for these compartments; as well, no risk is expected neither for secondary poisoning nor for groundwater contamination. Due to insufficient evidence, the potential of decoquinate to prevent coccidiosis in chickens for fattening cannot be established.