It's official: date labels on food don't quite represent the peril that people think.

For years, foodmakers have put sell-by and use-by dates on a number of products. But some food experts and environmentalists have argued that people are throwing out perfectly good food because of those dates. And on Thursday, the U.S. Department of Agriculture agreed.

The department's food safety division released new industry guidance that recommends that manufacturers use the phrase "best if used by" rather than "sell by" or "use by" when putting dates on food.

Infant formula is the only food product required by the U.S. Food and Drug Administration to date its products to ensure the nutrient levels match what is on the nutrition label.

No other products require dates, but manufacturers put them on labels to signal to retailers and consumers when products taste best. The USDA estimates that nearly one-third of all food is thrown away uneaten, something the agency is trying to reduce through better policies or simple packaging changes.

"Research shows that this phrase conveys to consumers that the product will be of best quality if used by the calendar date shown," the USDA wrote in its guidance. "Foods not exhibiting signs of spoilage should be wholesome and may be sold, purchased, donated and consumed beyond the labeled 'Best if Used By' date."

Because the U.S. has no uniform date labeling standard, a variety of terms are used. A "sell-by" date is not a safety issue but is meant to help a retailer know how long to display a produce for sale. A "use-by" date is also not a safety issue, but is the last date recommended to consumers for peak quality.

This guidance is part of the Agriculture Department and Environmental Protection Agency's goal of reducing food waste by 50 percent by 2030, an initiative announced last year.

A 2013 study by Harvard University's Food Law and Policy Clinic found that the vast majority of Americans have tossed out food over safety concerns based on the package's date.

"Faced with a range of phrases and dates stamped on food products, few of which are defined or regulated, consumers misinterpret date labels," the researchers found. "Erring on the side of caution and hoping to avoid spoiled or unsafe food, many Americans wind up tossing food out when it is often still good to eat."

The USDA's new guidance appears aimed chiefly at meat, poultry and dairy producers like Hormel Foods. Contacted about the new guidance, the Austin, Minn.-based company noted it provides more detailed information on QR labels that consumers can scan with their smartphones. Beyond that, the company said, "We are discussing with our brand teams to determine next steps."

The Food Safety and Inspection Service division of the USDA, generally concerned with precautionary food safety measures, developed these new guidelines — presenting an inherent tension between food safety and food sustainability.

"I think it's a good step, but it's a complex step," said Bill Marler, a food safety expert and lawyer in Seattle. "This will be clearer for consumers of all sorts. But now the trick is developing the tools to help consumers not waste food while also not consuming food that has harmful bacteria in it."

The USDA says food can be consumed after its "best if used by" date so long as there are no signs of spoilage.

"Spoiled foods will develop an off odor, flavor or texture due to naturally occurring spoilage bacteria. If a food has developed such spoilage characteristics, it should not be eaten," wrote the USDA.

The exception is pathogenic bacteria, which is undetectable. If an unlucky consumer purchases a food product carrying this pathogen, however, the expiration date won't protect them regardless.

The USDA says the best safeguard against eating dangerous foods is to follow storage instructions, like "refrigerate immediately after opening." And Marler said his greatest concern for consumers is fresh or freshly packed foods.

"But a lot of these products don't really have safety concerns, like ketchup and mustard that wind up in the back of the fridge that has a use-by date," Marler said. "That is more about the look and palatability look of the product rather than the safety."

Kristen Leigh Painter • 612-673-4767