On May 22, 2003, the draft Report on the toxicology and carcinogenesis studies of acesulfame potassium received public review by the National Toxicology Program’s Board of Scientific Counselor’s Technical Reports Review Subcommittee. The review meeting was held at the National Institute of Environmental Health Sciences, Research Triangle Park, NC.

Dr. R. Irwin, NIEHS, introduced the studies of acesulfame potassium in genetically modified mice by describing the uses of the sweetener, its nomination as a presumptive negative control for evaluation of the transgenic mouse models, the study design, and the survival, body weight, and histopathology observations. The proposed conclusion was:

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%. Because this is a new model, there is uncertainty whether the study possessed sufficient sensitivity to detect a carcinogenic effect.

Dr. Storer, the first principal reviewer, agreed with the conclusions. He felt it more appropriate to characterize the Tg.AC mouse model as a zeta-globin promoter activation model with an oncogenic H-ras reporter phenotype than as a gain of oncogenic function H-ras model.

Dr. Elwell, the second principal reviewer, agreed with the conclusions and inquired if the mice might have been able to tolerate a higher dose. Dr. Irwin replied that in another study with CD-1 mice a mild weight gain depression was seen at this top dose.

Dr. Piegorsch, the third principal reviewer, also agreed with the conclusions.

Dr. Storer moved, and Dr. Elwell seconded, that the conclusions be accepted as written. The motion was then approved unanimously with eight votes.