Food safety: Sell by date explained

One of the most frequently asked questions I get from friends and relatives who know my profession is about the safety of foods in the refrigerator found to be beyond their “sell by” or “use by” dates.

Surprisingly, food dating tells us very little about the actual safety of the food. According to the United States Department of Agriculture (USDA) Food and Inspection Service:

  • The “sell by” date tells the store how long to display the product for sale. Consumers should not buy the product after this date.
  • The “best if used by” (or “before”) date tells consumers how long the product will retain its best flavor, quality or nutrient quality. It is not a purchase or safety date.
  • The “use by” date tells consumers the last date that is recommended for using the product while at peak quality. The manufacturer determines this date.

Label dating is not required by federal law, but more than 20 states require dating of some foods. The USDA only requires label dating when poultry is packed. It has been argued that food label dating is used by food manufacturers mostly for business purposes, with little consideration for the actual safety of foods. Since there are no safety standards attached to label dating definitions, one should look beyond the date to determine the safety of the food in question.

Common sense tells us that if a food tastes funny, looks nasty or smells bad it is unsafe to eat. However, variations in the human ability to sense subtle changes in odor, appearance and taste make smell, sight and taste unreliable indicators of food freshness. More importantly, the typical causes of food spoilage (bacteria, molds, moisture and exposure to oxygen) are not usually the causes of food poisoning. In fact, many of the types of bacteria involved with food poisoning such as E. coli, noroviruses and salmonella cannot be detected by taste, sight or smell. These kinds of bacteria are commonly introduced to food during the storage, preparation or handling process and may be present in foods eaten before their “use by” or “sell by” dates have passed.

If food is stored and handled properly, many foods can be safely eaten and enjoyed after the label-date-defined shelf life.

Here are some tips from the USDA Food and Inspection Service and Kitchen Companion: Your Safe Food Handbook for deciding how long to keep some common food items, along with storage and handling suggestions to extend shelf life:

  • Do not purchase items after their “sell by” or “use by” dates have passed.
  • Go home as quickly as possible after food shopping. If you will be out longer than 30 minutes, bring a cooler.
  • Follow the 2-Hour Rule: Refrigerate perishable food within two hours. Refrigerate within one hour if the temperature is 90 degrees or higher.
  • Eggs cracked on the way home should be removed from the shell and stored in a covered container for up to two days.