In 2020, EFSA evaluated existing data and identified a no-observed-adverse-effect level (NOAEL) of nitrate exposure of 410 mg/kg body weight/day for pigs, and in 2021, Doepker et al. identified a higher NOAEL for nitrate, between 600 and 800 mg/kg body weight/day using methemoglobin blood measurements and the manifestation of methemoglobinemia as the most sensitive endpoints. Here, HBG2 is linked to methemoglobinemia.