More than 80% of grocery products contain bioengineered ingredients but less than 50% of consumers realize G.M.O. products are sold in supermarkets and only about a third of consumers think they have consumed foods derived from ingredients that have been genetically modified, said John Bode, president and chief executive officer of the Corn Refiners Association at the International Sweetener Colloquium here Feb. 10.

There is a gap in consumer understanding of bioengineered foods, Mr. Bode said as he opened a panel discussion on G.M.O. labeling at the Colloquium, which is sponsored by the Sugar Users Association.

Michael Hansen, Ph.D., senior staff scientist for the Consumers Union, noted that more than 90% of sugar beets, corn, soybeans, canola and cotton planted in the United States comes from bioengineered seed and that consumers had a right to know what was in the food they buy.

Mr. Hansen said the U.S. Food and Drug Administration has been inconsistent in statements about the safety of G.M.O. foods and has never made a conclusion about the safety of such foods. He maintains that U.S. testing and labeling laws should at least meet the minimum standard outlined in the international Codex Alimentarious. In the absence of a national U.S. labeling requirement, he said he supported individual state labeling efforts. He also said he supported G.M.O. labeling of individual ingredients listed on food products.

“This issue is not going to go away at the grass roots level,” Mr. Hansen said.

Michael Gruber, senior vice-president of federal affairs for the Grocery Manufacturers Association, said state-by-state labeling would not work and would increase the price of food. Food manufacturers, not retailers, would face fines and be open to increased lawsuits from trial lawyers, he said. Even though a labeling law may apply to an individual state, it will affect the entire supply chain, he added.

Mr. Gruber said the G.M.A. was seeking a national solution to G.M.O. labeling and wanted the F.D.A. to establish standards for food safety.

“Let’s have the F.D.A. be the authority over food labeling,” Mr. Gruber said, although he noted that adding such a label may imply a government warning about a product. The issue of G.M.O. labeling revolves around transparency and is not a health or safety issue, he said.

Mr. Hansen maintained that G.M.O. labeling would not imply a food was not safe.

Both speakers indicated there would be movement on national labeling bills in the near future.