NTP toxicology studies of acesulfame potassium (CAS No. 55589-62-3) in genetically modified (FVB Tg.AC Hemizygous) mice and carcinogenicity studies of acesulfame potassium in genetically modified [B6.129-Trp53(tm1Brd) (N5) Haploinsufficient] mice (feed studies)mice.

Unlabelled: Acesulfame potassium is an artificial sweetener used throughout the world in food and beverages. Acesulfame potassium was nominated by The Center for Science in the Public Interest because of its widespread use. Male and female Tg.AC hemizygous and p53 haploinsufficient mice were exposed to acesulfame potassium (at least 99% pure) in feed for 9 months. Genetic toxicology studies were conducted in mouse peripheral blood erythrocytes. 9-MONTH STUDY IN Tg.AC HEMIZYGOUS MICE: Groups of 15 male and 15 female Tg.AC hemizygous mice were fed diets containing 0%, 0.3%, 1%, or 3% acesulfame potassium (equivalent to average daily doses of approximately 420, 1,400, or 4,500 mg acesulfame potassium/kg body weight to males and 520, 1,700, or 5,400 mg/kg to females) for 40 weeks. Exposure to acesulfame potassium had no effect on survival or mean body weights. Feed consumption by the exposed groups was similar to that by the control groups throughout the study. There were no neoplasms or nonneoplastic lesions that were attributed to exposure to acesulfame potassium. 9-MONTH STUDY IN p53 HAPLOINSUFFICIENT MICE: Groups of 15 male and 15 female p53 haploinsufficient mice were fed diets containing 0%, 0.3%, 1%, or 3% acesulfame potassium (equivalent to average daily doses of approximately 475, 1,500, or 4,700 mg/kg to males and 570, 1,800, or 5,700 mg/kg to females) for 40 weeks. Exposure to acesulfame potassium had no effect on survival or mean body weights. Feed consumption by the exposed groups was similar to that by the control groups throughout the study. There were no neoplasms or nonneoplastic lesions that were attributed to exposure to acesulfame potassium.

Genetic toxicology: Acesulfame potassium did not increase the frequency of micronucleated erythrocytes in peripheral blood of male or female Tg.AC hemizygous mice administered 0.3% to 3% in dosed feed. A similar study was conducted in p53 haploinsufficient mice, and a significant exposure concentration-related increase in the frequency of micronucleated erythrocytes was noted in males but not females.

Conclusions: Under the conditions of this 9-month feed study, there was no evidence of carcinogenic activity of acesulfame potassium in male or female p53 haploinsufficient mice exposed to 0.3%, 1%, or 3%.