In fact, in November, Aventis CropScience, which makes the corn, once again asked the Environmental Protection Agency to approve StarLink for human consumption, pointing to new research it said showed there was no risk of allergic reactions. Aventis had returned its license to sell the corn in the future but wanted the variety approved for past seasons to limit disruptions in the corn market -- and, some contend, its own financial liability.

The company argued then that the quantities of StarLink in processed food are too small to cause allergic reactions and that its research showed that the Cry9C protein was destroyed in producing food such as tacos. The Cry9C found in tests of tacos was from cell DNA rather than actual protein, the company said, and so could not cause an allergic reaction.

An EPA expert panel concluded several weeks later that there was a "medium likelihood" StarLink protein could cause an allergic reaction but that there was a "low probability" that people had developed the needed sensitivity because of the limited amount of the corn in the food supply. However, the panel recommended that the EPA not act on the Aventis request until a test was created and used to evaluate reports of allergic reactions to StarLink.