A study finds consumers across Iowa and nationwide are throwing away perfectly good food because of confusion over the “use by,” “sell by” and “best by” dates on packaged foods.

Dana Gunders, with the Natural Resources Defense Council, co-authored a report that finds tons of good food ends up in our trash cans. Gunders says about 40-percent of our nation’s food supply is thrown out when it’s still safe to consume.

Gunders says, “Given that each year, Americans spend up to $2,275 per household of four on food they throw out, the average household of four is losing up to $450 per year on food that is needlessly thrown away.”

A recent Iowa Department of Natural Resources study found almost 14% of all trash dumped in the state’s landfills is food waste, or about 350,000 tons a year. The problem is getting worse, as the study found the amount of food waste being chucked in Iowa landfills has risen 62% in the past 13 years.

Food science engineer Ted Labuza says if stored and handled properly, the food can last for days or even weeks beyond that date and can safely be consumed with no worry of illness.

“About 80% of the dates are guesses from some consumer questionaires or based on what competitors are putting on,” Labuza says. “The others are done in very controlled conditions, food testing in order to determine when the taste of the product changes enough for the consumers to be displeased. I look at shelf life as the percentage of consumers that you’re willing to displease.”

Expiration dates on food vary from state to state and between food company. Gunders says she’d like to see a country-wide system in place.

“People are throwing away food on the dates they see on products because they believe those dates mean the food is no longer safe to eat,” Gunders says, “however, those dates almost never have a direct link to the food safety.”

Gunders says “use by” and “best by” dates on packaging are placed there by the manufacturer which determined after that time the product loses its maximum freshness. She says the “sell by” date is basically a tool for manufacturers and retailers so they can rotate product on the shelves.

Iowa has 46 municipal solid waste landfills but only four of them offer a food waste composting program. Nationwide, 40% of all food produced ends up in landfills.