Following a request from the European Commission,
EFSA
was asked to deliver a scientific opinion on the safety and efficacy of ferric (
III
) ammonium hexacyanoferrate (
II
) as technological feed additive for ruminants (domestic and wild), calves prior the start of rumination, lambs prior the start of rumination, kids prior the start of rumination and pigs (domestic and wild). The additive is already authorised for use in ruminants (domestic and wild), calves prior the start of rumination, lambs prior the start of rumination, kids prior the start of rumination and pigs (domestic and wild). The additive is effective at the minimum recommended concentration of 50 mg/kg complete feedingstuffs (corresponding to about 10 mg/10 kg bw) in reducing the contamination of food derived from ruminants (domestic and wild), calves, lambs and kids prior to the start of rumination, and pigs (domestic and wild) by caesium. Considering the scarce information available, the Panel is not in the position to conclude on the safety of the additive for the target species. The use of ferric (
III
) ammonium hexacyanoferrate (
II
) in feed for ruminants, calves, lambs, kids and pigs at the maximum recommended concentration of 500 mg/kg feed (corresponding to about 150 mg ferric (
III
) ammonium hexacyanoferrate (
II
)/10 kg bw) is safe for the consumer. In the absence of data, the Panel is not in the position to conclude on the safety of the additive for the user. The use of ferric (
III
) ammonium hexacyanoferrate (
II
) as a feed additive is considered safe for the environment.