Scientific Opinion on the re-evaluation of gold (E 175) as a food additive

The present opinion deals with the re-evaluation of the safety of gold (E 175) when used as a food additive. Gold (E 175) was previously evaluated by the Scientific Committee on Food (SCF) in 1975. The Joint FAO/WHO Expert Committee on Food Additives (JECFA) has not reviewed gold due to lack of data. None of the Committees established an acceptable daily intake (ADI). The Panel noted the limited data on absorption, distribution, metabolism and excretion (ADME) of elemental gold and the absence of toxicological data on gold used as a food additive (E 175) and considered the data to be too limited to perform a risk assessment for E 175. Elemental gold has a very low solubility and thus the systemic availability and effects are expected to be low. In contact with tissues ionic gold can be released from elemental gold and a high local concentration of gold can be reached at the site of contact. The Panel noted that no data on subchronic, chronic toxicity and genotoxicity of elemental gold were available. The Panel concluded that, despite the absence of toxicity data, but taking into account the low solubility of elemental gold, systemic availability and thus systemic effects of elemental gold would not be expected. The Panel recommended that the specifications for gold (E 175) should include the mean particle size and particle size distribution (± SD), as well as the percentage (in number) of particles in the nanoscale (with at least one dimension below 100 nm), present in the powder form of gold (E 175). The methodology applied should comply with the EFSA Guidance document. Exposure estimates of gold (E 175) reached up to 1.32 µg/kg body weight (bw)/day in the maximum level exposure assessment scenario and up to 0.33 µg/kg bw/day in the refined, non-brand-loyal, exposure scenario.