June 25, 2018
The Truth Behind Expiration Dates

The Truth Behind Expiration Dates

by Berkeley Wellness  

Your toothpaste just "expired." What do you do—resuscitate it or toss it? Though many products—from foods and medications to beer and condoms—carry expiration dates, the system is not an exact science and instead is best used as a general guideline. Nor are expiration dates uniformly regulated; not all states even require them. How long a product remains good also depends on how it’s been stored and handled.

Still, it's a good idea to select products with the latest dates. Here's what some dates mean:

  • "Sell by" indicates when products should be pulled from the shelf, but it isn't illegal for stores to stock products past this date. Sometimes stores reduce the price of such goods.
  • "Best if used by" or "use by" ensures that the product is at its best quality, after which it may deteriorate in flavor, texture, or appearance, but may still be safe.
  • "Expires on" or "EXP" is the last date a product should be used, though there are some exceptions.

In addition to, or instead of, an expiration date, many products carry coded (or "closed") dates, which refer to packing or manufacture dates. They often use a 3-digit number (from 001 to 365) representing the day of the year, sometimes preceded by the last digit of the year (a product made on January 1, 2008 would be coded 8001, for example). If you can figure out a coded date—a big if—it reveals how old the product is, something the manufacturer may not want you to readily know.

How to interpret a product's expiration date depends in part on what sort of product it is. Here are the main ones to keep in mind:

Food. Only infant formulas, some baby foods, and poultry are actually required by federal regulations to have dates; labeling of other foods depends on state laws. In general, buy foods before their sell-by dates, and observe use-by dates. Foods past their dates are often still safe, however, if they’ve been handled and stored properly (refrigerate perishables at 40° F or below). Milk can stay fresh up to a week after its sell-by date; eggs can last three to five weeks at home (purchase eggs before their expiration or sell-by date and store the carton on the refrigerator shelf, where it is colder, not in the door). Use or freeze fresh meat and poultry within a couple of days of buying. Dates on cans mean "best if used by," but when stored in a cool, dry place and not damaged, the contents may be safe indefinitely, even if taste degrades.

Improperly handled foods can go bad, though, long before any of these dates. Use common sense—if a food looks or smells bad, or if a can is bulging (a sign that bacteria, such as those causing botulism, may be present), throw it out, no matter what the date.

Drugs. Expiration dates guarantee that drugs (both prescription and over-the-counter) are potent and safe. They do not mean, however, that the medication is not effective or safe afterward. In many cases, drugs are stable far longer, but there’s little incentive for manufacturers to test them to see how long they will really last, since longer expiration dates would cut down on sales. Drugs do begin to break down after the bottles are opened and when they are exposed to heat, humidity, light, and temperature fluctuations—so you should store them in a cool, dry, dark place, not in the bathroom, and not in your car or pocket for long periods. If in doubt about your medication, consult a pharmacist.

Toothpaste. According to Colgate, its toothpastes are good for 12 to 18 months past the expiration date (which is two years after manufacture), beyond which there may be some loss in fluoride stability, ingredients may separate out or crystallize, and flavors may diminish. Toothpaste past its expiration date will not harm you, though. Other companies advise tossing toothpaste after the date, which is in their best interest since that increases sales.

Sunscreens. Most sunscreens have a three- to five-year shelf-life from time of manufacture, and carry either an expiration date or a coded manufacture date. Heat and humidity can reduce sunscreens' potency, so you should store them in a cool, dry place. Of course, if used properly—you need to apply a lot, frequently—you’re unlikely to have any left over, and expiration dates won’t be a concern.

What NOT to use past their dates

Certain drugs. Insulin, nitroglycerin, EpiPens (for severe allergic reactions), and liquid antibiotics degrade relatively quickly. Although there's no good evidence that these drugs become harmful after their expiration dates, you need to be able to count on getting their full potency. Toss any other expired drugs that are essential for your health, and any that are discolored, develop a strong smell, or have turned powdery. In general, liquid medications and those that require refrigeration are less stable.

Condoms. Condoms have either an expiration date, after which they should not be used, or a manufacture date, after which they are good for up to five years. Outdated condoms are more likely to break. Store condoms in a cool, dry place—not in your wallet or the glove compartment. Do not use them if they are sticky or dry or if the wrapper is damaged.

Infant formulas and baby food. Buy and use before their "use-by" dates, after which nutrient levels and quality decline.

See also: Test Your Food-Safety Smarts