AUGUSTA, Maine — The State House debate over requiring labeling of food products that have been genetically modified is one of many similar debates now raging throughout the country.

It is also a debate that has been underway in Maine for 20 years. Legislative proposals to require labeling of consumables that contain genetically modified animal or plant organisms (GMOs) have been floated, debated and abandoned then and in 1993, 1995, 1997 and 2001.

GMOs are plants and animals created through gene-splicing techniques that combine the genetics of different species. An estimated 94 percent of America’s soybean crop, 90 percent of its cotton crop and 88 percent of its corn crop has been genetically engineered to resist pests and climatic conditions such as drought. Consumer products considered at risk to GMO modifications include meat, milk and eggs, given that feeds contain GMO-engineered grains.

Since 20 years ago, proponents of labeling have included the Unity-based Maine Organic Farmers and Growers Association. Heather Spalding, the group’s acting director, said Wednesday afternoon that she is more optimistic than ever that the current push for labeling, as proposed in LD 718, will succeed.

“There’s a lot more public awareness and concern about this issue, and in terms of this proposed legislation, a lot more bipartisan support,” she said. “There are 123 co-sponsors within the Legislature, including many Republicans. The sponsor of the bill, Rep. Lance Harvell of Farmington, is a conservative Republican. There is much more broad-based support for this than we’ve seen in the past four rounds.”

Spalding characterizes the labeling effort as an issue steeped in the consumers right to know what they are eating and feeding their children. She was among the dozens of people who testified Tuesday during a State House public hearing that lasted almost seven hours.

Spalding refutes the argument made by opponents to labeling who claim consumers have been buying and eating GMO-based food for decades without any reports of associated health issues.

“That’s a fallacy in the sense that what little testing has been done on the health effects has been done by the food industry, and the results have been guarded and not released for peer review,” she said. “You can’t say there are no health effects when you haven’t been testing for them. There is emerging science, some of it out of Europe that there are significant ‘scientific uncertainties’ about the impact of GMOs on human health. We see labeling as a risk-management strategy.”

GMO-manipulated food products are banned in many European countries.

Shelley Doak, executive director of the Maine Grocers Association, said Wednesday that a state-mandated labeling law would prove a costly burden to the state’s grocers and an inconvenience to consumers.

“It would prove expensive for Maine farmers, processors and manufacturers to implement and enforce such regulations,” she told the Bangor Daily News. “If the Food and Drug Administration, the U.S. Department of Agriculture, and the [Environmental Protection Agency] felt that these products needed to be labeled, we would support that. Consumers expect reliable, fact-based labeling that are statements of fact backed by scientific evidence.

“And how likely will out-of-state product producers be willing to change their labels [to accommodate Maine]? Either they will not send their products to the state of Maine, or will ship in their products and tell independent grocers that they are responsible for affixing stickers on products.”

Food labeling policies similar to the measure now being debated in Augusta also are under consideration in 36 other states. Legislative bills are actively under consideration in Connecticut, Maryland, New Hampshire, New Jersey, New York, Pennsylvania, Vermont and Minnesota. The labeling requirement is on this year’s November ballot for voters in Washington state.

Opponents to the Maine proposal also argue that any requirement for product labeling should be a federal, not a state, regulatory issue. Spalding agrees, but says the federal process has taken too long, forcing Maine and other states to take action.

“Efforts at the federal level have been moving too slow,” she said. “This is not an issue for which we can wait for Congress to act.”

GMO techniques have not been applied to any of three of Maine’s dominant agricultural crops: potatoes, broccoli or blueberries. They have been applied elsewhere to apples and to farm-raised salmon, which are also Maine commodities.

The legislative committee on Agriculture, Conservation and Forestry has yet to schedule a work session on LD 718.