A yogurt pot says “use by”, a bag of pasta says “best before end”, and an imported box of cookies sometimes says “sell by”. They look like three ways of saying the same thing. Only the first one is a statement about safety.
The confusion is expensive. In April 2016, researchers at Johns Hopkins surveyed 1,029 American adults, and 84% said they throw food away near the package date at least occasionally. The EU wastes 88 million metric tons of food a year, and a 2018 European Commission study linked up to 10% of it to date marking. Explaining helps, though. In another US survey of 2,607 adults, 64.0% knew the general meaning of “Best If Used By” and only 44.8% knew “Use By”. After an explanatory message, understanding rose to about 82% for both.
The two dates the law recognizes
EU rules and Ukrainian law work with the same pair of dates. Under the Ukrainian Law on Food Information for Consumers (No. 2639-VIII), a packaged food must carry one of them.
- “Use by” goes on foods that are highly perishable from a microbiological point of view. In the EU, food past its use-by date is deemed unsafe. The Ukrainian law says such food may be considered dangerous to health.
- “Best before” (or “best before end”) is the date of minimum durability. Until then, the food keeps the properties the manufacturer specified, provided it was stored as the label says.
The UK government guidance puts it in one line: use-by dates relate to safety, best before dates relate to quality.
The Ukrainian law also sets the date format. Food that keeps up to three months needs day and month, up to 18 months month and year, and beyond that the year alone. A packet showing only a year was designed to last over 18 months.
Some foods may skip the minimum durability date. These include whole fresh fruit and vegetables, wine, drinks with 10% alcohol or more, and bread eaten within a day. Vinegar, salt, sugar and chewing gum are on the list too. So a bag of fresh potatoes may carry no date at all, and judging the tubers is up to you, as our piece on green potatoes explains. Sprouted seeds and sprouted legumes are explicitly excluded from that exemption, so sprouts must carry a date. Why sprouts get special treatment is covered in our piece on sprouts and microgreens risk.
Where “sell by” comes from
Neither Ukrainian nor EU rules have a third date. “Sell by” comes from American packaging, and even in the United States it has no federal definition.
US federal regulations require a date on one product only: infant formula. That label reads “Use by” with a month and year, and it is about nutrition and quality. Until that date, the formula must contain at least the nutrients stated on the label. It must also stay of acceptable quality, for example by passing through an ordinary bottle teat.
For everything else, date labels are voluntary and manufacturers choose the wording. The wording has to be truthful and not misleading. In 2017, the trade groups FMI and GMA counted more than ten phrases in use. Among them were Sell By, Best Before, Expires On, Use By, Best By, Born On and Enjoy By. They proposed cutting these down to two: “BEST If Used By” for quality and “USE By” for safety. The FDA and USDA now recommend the first. “Sell By” did not make the list.
The cleanup is unfinished. In December 2024, the FDA and USDA’s Food Safety and Inspection Service opened a joint Request for Information on food date labeling. By an FDA estimate, date confusion accounts for about 20% of consumer food waste. And in the 2016 survey, over a third of Americans wrongly believed date labels were federally regulated, while another 26% were unsure.
“Sell by” has no fixed meaning, so it tells you nothing reliable about safety. Look for a use-by or best-before date instead. In Ukraine, mandatory food information, the date included, must appear in Ukrainian.
Why your nose cannot check a use-by date
The European Food Safety Authority (EFSA) is blunt about it in its 2020 guidance. Pathogenic microorganisms do not generally cause spoilage of food. They are rarely the dominant group in a food’s microbiota, unless processing such as pasteurization has sharply reduced everything else. Changes in taste, smell and appearance come from other bacteria, the spoilage organisms.
A best-before date is based on the growth of spoilage bacteria and the resulting decline in taste, smell and look. For a use-by date, EFSA says the shelf life should never exceed the shorter of two periods. One is how long the food stays pleasant, the other how long it stays safe. After a best-before date, your senses are a real check. After a use-by date, they guarantee nothing.
Cold does not fully solve this. The minimum growth temperature of Listeria monocytogenes is somewhere between 31.3 and 29.3°F (-0.4 and -1.5°C), depending on the source, so it keeps multiplying in the fridge. Salmonella needs 41-45°F (5-7°C) and pathogenic E. coli 43.7°F (6.5°C). Proper refrigeration, for example below 39°F (4°C), stops their growth, while a warmer fridge may let them grow. How few cells it can take to make someone ill is explained in our article on infectious dose.
In a 2024 Swedish study, chicken breast fillets packed in a modified atmosphere were stored at 39 and 46°F (4 and 8°C). They were tested on the use-by date and again two and four days later. Total bacterial counts rose from about 6.5 to 8.0 log CFU/g, roughly a thirtyfold increase. Yet sensory tests found no significant difference between the cooked fillets. The authors note that these counts were close to or above levels associated with spoilage. Pathogens were not counted separately, so the study supports one conclusion only: the senses missed the change.
When “best before” is on the wrong product
The manufacturer decides which of the two dates to use. EFSA built a decision tree to help, but mistakes happen.
Veterinary scientists at the University of Messina, in a paper published in 2026, tested 43 ready-to-eat products labeled “best before”. There were 26 dairy products and 17 meat products, 13 of them cooked. One pack from each lot was analyzed on the date. A second pack was kept for another seven days at 45°F (7°C) to mimic a warm home fridge.
- Three cooked meats already had unsatisfactory microbial loads on the date: roast turkey, Lyoner sausage and cooked shoulder. A week later, mortadella joined them.
- Among the dairy products, a sweet gorgonzola was spoiled on the date, and a brie joined it a week later.
- Sensory analysis confirmed the lab results.
The authors concluded that food in this state meets the EU definition of unsafe food and should be sold with a use-by date. So keep cooked sliced meats and soft cheeses cold and treat them as use-by foods, even when the label says best before.
The date assumes a proper fridge
Both dates hold only if the food was stored as the label says. Where the label tells you to refrigerate, UK guidance specifies 41°F (5°C) or below. It also warns that food stored badly can become unsafe before its use-by date.
Real fridges often run warmer. Across 361 Scottish households, the mean fridge temperature was 41.3°F (5.17°C), and 55.4% of fridges ran above the recommended 32-41°F (0-5°C). EFSA cites studies from eight European countries with mean temperatures of 41.7 to 50.8°F (5.4 to 10.43°C) and maximums of 48.7 to 71.2°F (9.3 to 21.8°C). Labels do not agree either. In 2,665 labels on chilled ready-to-eat foods from ten countries, recommended storage temperatures ranged from 39 to 54°F (4 to 12°C). A warm fridge is especially risky for vacuum-sealed food, where botulism bacteria can grow from about 37°F (3°C); see our piece on vacuum sealing myths.
Put a thermometer in your fridge and see what it actually reads. Keep perishables in the main compartment, away from the door. According to EFSA’s review, the middle shelf is usually the coldest spot and the door the warmest. For microgreens, real storage times at different temperatures are collected in our wiki on microgreens shelf life.
What you can do before a use-by date
Food past its use-by date should not be eaten, with one exception. UK guidance allows it if you cooked or froze the food on or before that date.
- Cool cooked food, keep it in the fridge and eat it within 48 hours, or freeze it.
- Keep the freezer at 0°F (-18°C). Bacteria cannot grow on frozen food, so it will not deteriorate. Label what it is and when you froze it.
- Once defrosted, use it within 24 hours.
Rice has a stricter rule: no more than one day in the fridge before reheating. The reasons are in our piece on reheating rice. What a second freeze does to food is covered in refreezing: what actually degrades.
How to check food after a best-before date
After this date, food is usually safe to eat, though the quality may have slipped. UK guidance suggests using sight, taste and smell.
- Look for visible mold on bread.
- Taste cookies or chips to see if they have gone stale.
- Smell dairy products to see if they have soured.
If you do find mold, our guide to mold on cheese, bread and jam explains when to cut and when to toss.
How many days past the date is still fine? There is no universal answer. EFSA declined to give indicative time limits even for food donated or sold past its best-before date. Products and consumer habits vary too much. Check the pack for opened-product instructions too. Ukrainian law lets the manufacturer state storage conditions and a consumption period after opening. It is an option, so the label may not have one.
What stores are allowed to sell
Here Ukraine is stricter than parts of Europe. Its food safety law (No. 771/97-VR), as amended in 2023, covers both dates. It bans the circulation of food whose use-by date or minimum durability date has passed. The law defines circulation broadly: sale and any other transfer, paid or free. Such food must be withdrawn or recalled.
Several EU countries allow selling food past its best-before date. In Sweden, stores may do so under their own responsibility and must judge whether the food is still fit to eat. In Greece, such products must be kept apart and labeled in capitals “PAST BEST BEFORE DATE”. In Norway, food with a short best-before date is sold at a discount by special online stores.
In a Ukrainian store, food past either date should not be on the shelf at all.
Summary
- First, find out which of the two dates the pack carries.
- Use by: eat, cook or freeze the food by that date. After it, throw the food out even if it smells fine.
- Best before: after the date, check with your eyes, nose and tongue. Cooked sliced meats and soft cheeses are the exception.
- Sell by: no fixed meaning, so look for a use-by or best-before date.
- Every date assumes proper storage. Check your fridge with a thermometer.
How bacteria travel between foods on boards and hands is explained in our guide to kitchen cross-contamination. The wider picture is in our food safety hub. In Ukraine the rest of the label went back to full requirements on October 1, 2026, when the wartime waivers were repealed. Why the date on a home-canned jar tells you nothing is shown through botulism in home canning, where acidity decides everything and the date decides nothing.
