Tartrates occur naturally in many fruits and high concentrations are found in wine. Consumer exposure data suggest that about 6mg each of tartaric acid and potassium acid tartrate added to foods are ingested daily per capita (a total of about 0.2mg per kg in an adult). The literature indicates that there are no differences in the biological effects of the several tartrates added to food and that their toxicity is dose related. Studies using modern tracer techniques would be helpful in ascertaining the extent of absortion and metabolic fate of ingested tartrates.
Tartrates are reported to elicit nephritic lesions in several animal species, but ususally only after parenteral injection of very large doses. Daily ingestion of 2.3g per kg of body weight per day for 150 days produced no ill effects in rabbits. No toxicity was found in rats ingesting up to 1.2g per kg of body weight of tartaric acid in the diet daily for 2 years. The daily intake of tartrates added to foods is orders of magnitude below that which could be expected to cause toxicity in man.
In light of the above, the Select Committe concludes that: There is no evidence in the available information on L(+) potassium acid tartrate, L(+) sodium potassium tartrate acid that demonstrates, or suggests reasonable grounds to suspect, a hazard to the public when they are used at levels that are now current, or that might reasonably be expected in the future.