Indigo carmine (2a132) as a colourant in feed for cats and dogs up to 250 mg/kg and for ornamental fish up to 1000 mg/kg, valid until 1 May 2035: total colouring matter ≥ 85 %, lead ≤ 2 mg/kg; spectrophotometry at 610 nm in the additive, LC-MS/MS in feed
Commission Implementing Regulation (EU) 2025/714, published on 11 April 2025, following a re-evaluation authorises indigo carmine as a sensory additive in the colourants group for cats, dogs and ornamental fish; it had previously been authorised without a time limit under Directive 70/524/EEC (for ornamental fish under the name “indigotine”). The Commission relies on the EFSA opinions of 28 April 2015 and 27 June 2024: indigo carmine with a purity of at least 85 % colouring matter is safe up to 250 mg/kg complete feed for cats and dogs and up to 1000 mg/kg for ornamental fish. A corrigendum of 27 April 2026 was published only in the Portuguese version.
- Annex: indigo carmine described as the sodium salt — mainly a mixture of disodium 3,3’-dioxo-2,2’-bi-indolylidene-5,5’-disulphonate and disodium 5,7’-disulphonate; calcium and potassium salts are also permitted; C₁₆H₈N₂Na₂O₈S₂, CAS 860-22-0 / 54947-75-0, chemical synthesis. Specification: total colouring matter ≥ 85 %, 5,7’ isomer ≤ 18 %, subsidiary colouring matter ≤ 1 %, isatin-5-sulphonic acid, 5-sulphoanthranilic acid and anthranilic acid together ≤ 0.5 %, unsulphonated primary aromatic amines ≤ 0.01 %, ether-extractable matter ≤ 0.2 %, lead ≤ 2 mg/kg.
- Methods in the annex: total colouring matter in the additive — spectrophotometry at 610 nm (FAO JECFA monographs No 1 volume 4 and Regulation (EU) No 231/2012); indigo carmine in compound feed — LC-MS/MS. EFSA verified the report of the EU reference laboratory amended in 2019, which recommends LC-MS/MS for determination in feed. In eight new batches colouring matter was 86.62–96.80 % (average 90.94 %; tartrate buffer titration — 86.4–97.2 %), the 5,7’ isomer 6.47–13.77 %, isatin-5-sulphonic acid 0.03–0.11 %.
- Purity of 85 % instead of 93 %: in 2015 EFSA limited its safety conclusion to indigo carmine with a purity of ≥ 93 %, because in the Dixit and Goyal (2013) study in mice indigo carmine of unknown purity damaged the testes at 17 and 39 mg/kg bw per day. A new 56-day study in male mice with 88 % indigo carmine showed no adverse effects up to 548 mg/kg bw per day; EFSA applied the NOAEL of 500 mg/kg bw per day from the 2-year rat study and calculated safe concentrations: dog 264, cat 220, ornamental fish 978 mg/kg — rounded to 250 and 1000 mg/kg. EFSA also recommended aligning the lead limit with the food additive (≤ 2 mg/kg) — the act adopts it.
- User safety (act, following EFSA): inhalation exposure to dust from the additive is considered hazardous in the absence of data on inhalation toxicity; indigo carmine is not irritant to skin or eyes but should be regarded as a potential skin and respiratory sensitiser — where procedures are not sufficient, skin and respiratory protection. Transitional period: additive and premixtures produced before 1 November 2025, compound feed and feed materials — before 1 May 2027. The applicant proposed typical rates of 10–200 mg/kg for cats and dogs and 500–5000 mg/kg for fish; the highest rates for fish exceed the safe 978 mg/kg.