Occurrence data of nickel in feed and animal exposure assessment
Nickel (Ni) is a silvery‐white, hard, ductile metal existing in oxidation states; in biological systems, Ni2+ is the prevalent form. All analytical results used to estimate animal dietary exposure were reported as Ni', without providing information on specific chemical species. Considering the data provided by Member states, among FoodEx level 1 feed categories, the highest mean Ni levels were measured in ‘Minerals and products derived thereof’ (n = 72). High mean Ni concentrations were also observed in ‘Compound feed’ (n = 516), in particular in complementary feeds for fattening cattles, unspecified complementary feed and complementary feeds for fattening pigs. Within grains used as feed (n = 597), the highest mean Ni concentrations were measured in oats. In addition, Ni concentrations in hydrogenated vegetable oils/fats were reported by industry. Exposure to Ni in livestock and companion animals varied according to the animal species. When considering the diets with hydrogenated vegetable oils/fats based on the reported Ni concentrations, the mean exposures varied between 6.0 μg Ni/kg body weight (bw) per day in cats and 79 μg Ni/kg bw per day in laying hens and the high exposure levels varied between 11 μg Ni/kg bw per day in cats and 127 μg Ni/kg bw per day in rabbits. The mean exposure estimates considering the maximum concentration of Ni assumed from good manufacturing practice in hydrogenated vegetable oils/fats (50 mg Ni/kg) varied between 27 μg Ni/kg bw per day in cats and 255 μg Ni/kg bw per day in rabbits; for the high concentration scenarios, exposures varied between 30 μg Ni/kg bw per day and 307 μg Ni/kg bw per day in the same species. The estimated exposures to Ni are in line with the one reported in the 2015 EFSA opinion, using a worst‐case scenario. When estimating exposure with a realistic scenario, using the reported Ni concentration in hydrogenated vegetable oils/fats, the exposure of livestock and companion animals is lower (approximately from 1.5 to 6 times, depending on the species) than the 2015 assessment.