Safety and efficacy of CAROPHYLL® Stay-Pink (astaxanthin dimethyldisuccinate) as feed additive for salmon and trout

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of astaxanthin dimethyldisuccinate (CAROPHYLL® Stay-Pink) as a feed additive for salmon and trout. CAROPHYLL® Stay-Pink (C®SP) is a feed additive, containing about 11 % astaxanthin dimethyldisuccinate (ATX-dimethyldisuccinate). The purpose of C®SP is to provide farmed Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) with a source of the carotenoid astaxanthin (ATX) which confers the characteristic pink colour to wild salmonids. Orally administrated ATX-dimethyldisuccinate is hydrolysed and converted to free ATX in the intestine of fish, then absorbed, metabolised and distributed in the same manner as free ATX. ATX-dimethyldisuccinate is efficacious in colouring the flesh of salmonids. This conclusion is based on studies comparing ATX-dimethyldisuccinate with free synthetic ATX, which produced similar results concerning flesh redness and ATX content in salmon and trout. Efficacy was demonstrated in the dose range of 20 to 100 mg ATX equivalents kg-1 feed, redness with tissue deposition reaching a plateau at about 60 mg ATX equivalents kg-1 feed. A dietary level of 908 mg ATX equivalents kg-1 complete diet provided as ATXdimethyldisuccinate from C®SP was well tolerated in rainbow trout for eight weeks. Although the short duration of the trial reduced the value of the study, taking into account former assessments of ATX, the FEEDAP Panel considers ATX-dimethyldisuccinate, at the highest authorised ATX level in feed, safe for the target species. The data submitted in the dossier indicated particularly that the colourant was not genotoxic (ATX-dimethyldisuccinate), carcinogenic or teratogenic (ATX). Consequently, supplementation of fish feed with ATX at the highest approved level (100 mg kg-1 feed) is unlikely to represent an additional risk to the consumer. Given the nature of ATXdimethyldisuccinate, its breakdown in the alimentary tract to ATX and its deposition as ATX in flesh, the FEEDAP Panel considers that no new or additional safety concerns from the use of ATX-dimethyldisuccinate, a substitutive product of other ATX sources, would originate for consumers. No dermal or ocular risk for the users of C®SP is likely to occur under practical conditions. In the absence of an acute inhalation study, the acute inhalatory toxicity cannot be established. However, since the acute oral toxicity is very low (>2000 mg kg-1 bw) and particle size is >150 μm, systemic exposure through the respiratory tract is considered of limited risk. The FEEDAP Panel does not expect that the use of ATX-dimethyldisuccinate will pose a risk to the environment. The FEEDAP Panel recommends a number of modifications to the Register entry proposed by the applicant. In particular, it is recommended to include the content of ATXdimethyldisuccinate and ATX equivalents of C®SP, a maximum content of dichloromethane and a reduction of the maximum TPPO content.