Sell by? Use by? What’s a shopper to do?

We’re getting pretty savvy about checking food labels for fat, calories and fiber, but labels of a different sort, such as “sell by” and “use by” can leave us guessing about whether to keep or toss food.

“The current system of food product dating in the U.S. can be confusing, and is not necessarily related to food safety,” said Kansas State University assistant professor, Londa Nwadike.

Shoppers sometimes shy away from buying a product because the “sell by” or “use by” date is close by. Or they buy it but don’t use it right away, only to notice later that the “sell by” date has come and gone. If unsure whether it’s safe to eat, the food is thrown away – sometimes unnecessarily, said Nwadike, who is a consumer food safety specialist for K-State Research and Extension and the University of Missouri.

She gave tips to keep shoppers safe and cut food waste to a minimum.

1) Infant formula is the only food product on which expiration dates are federally regulated. Don’t buy or use baby formula after its “use-by” date, for both safety and nutritional reasons.

2) Some states do require dating of some foods, but other than infant formula, there is no regulated food dating system across the U.S. Some groups have made recommendations to standardize the system used, but at this time, dates are put on products in a variety of ways. The U.S. Department of Agriculture provides definitions for some terms used on food product labels:

· “Sell by” date: Tells the store how long to display the product for sale. You should buy the product before that date.

· “Best if used by (or before)” date: Recommended for best flavor or quality. It is not a purchase or safety date.

· “Use by” date: The last date recommended by the manufacturer for the use of the product while at peak quality.

These dates generally refer to food quality, rather than safety, Nwadike said. However, they can give a general idea of how long the food has been in the market.

3) Many canned foods are required to have a packing code which enables manufacturers to rotate their stock and locate their products in the event of a recall. These codes are not meant for consumers to interpret as use-by dates (unless they are clearly marked as a “use-by” date).

4) The most important thing consumers can do to impact the length of time they can safely keep and use food is to handle it properly. This includes:

· If perishable, take the food home immediately after purchase and refrigerate it (at 40°F or below) within at least two hours. Freeze it if you can’t use it within recommended safe refrigerated storage times. Once a perishable product is frozen, microbial growth stops, so it will be as safe as it was when it went into the freezer.

· Store foods in the cupboard, refrigerator or freezer at the proper temperature and length of time. Do not leave perishable foods at room temperature more than two hours. If you know that a carton of milk has been sitting on the counter more than three hours, throw it out regardless of what date is on the container.

· If the product has a “use-by” date on the package, follow that date to determine when to use it.

· Follow the handling and preparation instructions on the product label.

· Avoid cross-contamination and ensure proper sanitation.

· If the product has visible mold, off odors, the can is bulging or other similar signs, this spoilage may be a sign that dangerous microorganisms are present. With such products, use the “If in doubt, throw it out” rule.

5) Be extra cautious with food to be consumed by vulnerable people such as young children, the elderly, pregnant women, and immune-compromised.

More information is available online:

· Food Product Dating. USDA. August 2013.;

· Safe Food Storage: The Refrigerator and Freezer. Kansas State Research and Extension. 2014:; and

· Safe Food Storage: The Cupboard. Kansas State Research and Extension. 2014:
– Story from K-State Research and Extension


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