Toxicology
In pure form, potassium sorbate is a skin, eye, and respiratory irritant.Concentrations up to 0.5% are not significant skin irritants.
As a food additive, potassium sorbate is used as a preservative in concentrations of 0.025–0.100%, which in a 100 g serving yields an intake of 25–100 mg. In the United States, no more than 0.1% is allowed in fruit butters, jellies, preserves, and related products.[18] Up to 0.4% has been studied in low-salt, naturally-fermented pickles, and when combined with calcium chloride, 0.2% made "good quality pickles." Potassium sorbate has about 74% of sorbic acid's anti-microbial activity. When calculated as sorbic acid, 0.3% is allowed in "cold pack cheese food." The upper pH limit for effectiveness is 6.5.
The maximal acceptable daily intake for human consumption is 25 mg/kg, or 1750 mg daily for an average adult (70 kg). Under some conditions, particularly at high concentrations or when combined with nitrites, potassium sorbate has shown genotoxic activity in vitro.