L-cysteine hydrochloride monohydrate from poultry feather keratin as a flavouring in cat and dog food renewed until 2036: ion-exchange chromatography IEC-VIS/FLD, purity at least 98.5 % and a new recommended maximum content of 25 mg/kg on the label
Commission Implementing Regulation (EU) 2026/2129, published on 25 September 2026, renews until 15 October 2036 the authorisation of L-cysteine hydrochloride monohydrate produced by hydrolysis of poultry feather keratin as a flavouring for cats and dogs and repeals Regulation 2015/2306. The Commission set no maximum content, but the additive label must state a recommended maximum content of 25 mg/kg complete feed. The EU reference laboratory considered its earlier evaluation of the methods still valid, so no new report was needed.
- Methods in the annex: qualitative identification according to the Food Chemicals Codex “L-cysteine monohydrochloride” monograph; quantification of cysteine in the additive — by ion-exchange chromatography with post-column derivatisation and optical detection (IEC-VIS/FLD); in premixtures — IEC-VIS according to Regulation (EC) No 152/2009. Purity of the additive: at least 98.5 %, formula C3H7NO2S·HCl·H2O, CAS 7048-04-6.
- Data from the EFSA opinion (5 batches): cysteine hydrochloride 99.9 % on dry matter, chloride 20.1 %, loss on drying 10.2–10.3 %, residue on ignition 0.03–0.04 %, specific optical rotation +6.0° to +6.2° (European Pharmacopoeia requirement +5.5° to +7.0°). In 3 batches: lead < 0.05 mg/kg, mercury 0.0065–0.0073 mg/kg, PCDD/Fs + PCBs 0.103–0.104 ng WHO-TEQ/kg, mycotoxins and pesticides below the limits of quantification, Salmonella not detected in 25 g, Stauber-Heubach dusting potential 3.8–7.5 mg/m³.
- Since the original authorisation the applicant changed some elements of the manufacturing process (EFSA redacted the details); according to EFSA they do not affect the composition of the additive. EFSA concluded that the additive remains safe for cats and dogs under the current conditions and that efficacy need not be assessed for the renewal. Already in 2013 EFSA noted that added cysteine is safe provided the balance between cysteine and methionine in the complete diet is maintained.
- If the dose on the premixture label would lead to exceeding 25 mg/kg, the premixture label must state the functional group, identification number 2b920, name and added amount. Because of dusting EFSA considered inhalation exposure likely and the additive an irritant to skin, eyes and mucous membranes; any exposure is a risk. Additive and premixtures made under the old rules before 15 April 2027 and pet food made before 15 October 2028 may be used until stocks are exhausted.