In the light of genotoxicity of cobalt(II) compounds and their presumed carcinogenicity after inhalatory exposure, the use of cobalt compounds as additives in animal nutrition has been assessed, considering (i) the necessity of its use for all animal species, (ii) its implications for consumer safety and (iii) on the safety of persons handling cobalt compounds. Since the only known role of cobalt in animals is that of the central atom of vitamin B 12 , only animals with the capacity of synthesizing vitamin B 12 in the intestinal tract like ruminants, horses and coprophagous rabbits can utilise cobalt. Consequently, there is no necessity for cobalt supplementation of feed for other animals. No data are available in the open literature on the potential carcinogenicity of cobalt following the exposure via the oral route either in humans or in experimental animals. The exposure of consumers to total dietary cobalt has been considered. There was no indication that the thresholds for non-carcinogenic events (i.e. cardio-myopathy, polycythaemia, goiter, developmental) would be exceeded at present. Users are exposed to cobalt compounds. In the re-evaluation of cobalt compounds their dusting potential deserves therefore particular attention. As a first step, the FEEDAP Panel recommends minimizing exposure of users. The FEEDAP Panel recommends modifying the authorisation of cobalt compounds in feedstuffs by (i) restricting the use of cobalt compounds as additives to feed for ruminants (except milk replacer), horses and rabbits, (ii) limiting cobalt supplementation in feed for ruminants (except milk replacer), horses and rabbits to a maximum of 0.3 mg Co/kg complete feed, and (iii) reducing the authorised maximum cobalt content from all sources from 2 to 1 mg/kg complete feed for all species except fish. Any negative consequences of these measures on animal health and the efficiency of animal production are not expected. © European Food Safety Authority, 2009 KEY WORDS Nutritional additive, compound of trace elements, cobalt, cobalt compounds, vitamin B 12 , safety 1 On request of EFSA, Question No EFSA-QSUMMARY According to Regulation (EC) No 790/2009 amending Regulation (EC) No 1272/2008, cobalt dichloride and cobalt sulfate are of low acute toxicity (category 4), but are classified as respiratory and skin sensitizers (category 1), as acute and chronic toxicants to the aquatic environment (category 1) and as presumed human carcinogens by the inhalatory route (class 1B). Cobalt(II) cations are also considered genotoxic under in vitro and in vivo conditions.In the light of the above properties of cobalt and since several cobalt compounds are authorised by EU legislation as feed additives, a risk assessment of the use of cobalt compounds in animal nutrition was undertaken considering (i) the necessity of cobalt supplementation for the target species including potential adverse effects of minimising/withdrawing cobalt supplementation on animal health, (ii) the safety for consumers of foods from animals treated with cobalt sal...
