The European Food Safety Authority (EFSA) has concluded that potassium ferrocyanide, used as an anticaking agent in potassium chloride feed additive, is safe for all animal species and the environment when used at a maximum concentration of 60 mg ferrocyanide anion per kg of potassium chloride. The revised opinion, adopted on 1 July 2026 and published on 24 July 2026, reverses a previous 2023 assessment that had deemed the additive unsafe for several species at the originally proposed level of 150 mg/kg KCl. The new conclusion is based on supplementary data submitted by the applicant, K+S Kali GmbH, and a recalculation of safety margins.
The 2023 opinion had identified maximum safe concentrations of ferrocyanide ions in complete feed for various species but found that, at 150 mg/kg KCl, the additive was not safe for chickens, laying hens, turkeys, piglets, veal calves, cattle for fattening, dairy cows, horses, rabbits, and cats. For pigs for fattening, lactating sows, sheep, goats, salmon, and dogs, the 150 mg level was considered safe. The earlier assessment also could not conclude on environmental safety for soil and marine compartments. In response, the applicant proposed reducing the maximum inclusion level to 60 mg ferrocyanide anion per kg KCl and provided additional environmental data. EFSA's Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) recalculated margins of safety for all target species, finding values above 1 for most, except dairy cows and rabbits, where margins were 0.8. However, the Panel noted that the calculations assumed all potassium requirements are met by supplemented KCl, ignoring natural potassium content in feed materials, particularly forages, which would increase the margin of safety in practice. The Panel concluded that at 60 mg/kg KCl, the additive is safe for all animal species and the environment.
The decision impacts feed additive manufacturers, who can now market potassium ferrocyanide at the lower concentration for all species, and livestock producers, who gain a safe anticaking agent for potassium chloride. The reduced level may limit anticaking efficacy, but the additive remains effective at the proposed use. The European Commission requested the new opinion under Article 29(1)(a) of Regulation (EC) No 178/2002, and the revised safety conclusion paves the way for potential EU authorization of the additive under Regulation (EC) No 1831/2003.