An application has been made for the re-authorisation of citric acid (anhydrous and monohydrate) when used as a preservative in feed and also for the new use in water for drinking for all animal species. Citric acid (anhydrous and monohydrate) is already authorised for use in food and feed as a preservative following the quantum satis principle. There is evidence from published studies that citric acid is safe for the target species when used up to 30 000 mg citric acid/kg complete feedingstuffs and the corresponding concentration in water for drinking (10 000 mg citric acid/L). The additive is, consequently, also safe for the target species at the proposed conditions of use of 15 000 mg citric acid/kg complete feedingstuffs and 5 000 mg citric acid/L in water for drinking. The quality of available data does not allow a margin of safety to be derived. The use of citric acid in animal nutrition is safe for the consumer. It is prudent to regard citric acid as potentially hazardous to workers by exposure of the skin, eyes or mucous membranes or by inhalation. The use of citric acid in animal nutrition would not pose a risk to the environment. Although citric acid is a well-recognised preservative in food, based on data provided the effectiveness of citric acid as a preservative in feedingstuffs and water for drinking was not sufficiently demonstrated. The Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) has reservations about the effectiveness of organic acids as preservatives in feedingstuffs with a typical moisture content of ≤ 12 %.