Expiration date

An expiration date or expiry date is a previously determined date after which something should no longer be used, either by operation of law or by exceeding the anticipated shelf life for perishable goods. Expiration dates are applied to selected food products and to some other manufactured products like infant car seats where the age of the product may impact its safe use.
Arbitrary expiration dates are also commonly applied by companies to product coupons, promotional offers and credit cards. In these contexts, the expiration date is chosen for business reasons or to provide some security function rather than any product safety concern.
Expiration date is often abbreviated EXP or ED. The legal definition and usage of the term expiration date will vary between countries and products.
Parallel names.
Best before.
"Best before" or "best by" dates appear on a wide range of frozen, dried, tinned and other foods. These dates are only advisory and refer to the quality of the product, in contrast with "use by" dates, which indicate that the product may no longer be safe to consume after the specified date. Food kept after the "best before" date will not necessarily be harmful, but may begin to lose its optimum flavour and texture. Eggs are a special case, since they may contain salmonella which multiplies over time; they should therefore be eaten before the "best before" date, which is, in the USA, a maximum of 45 days after the eggs are packed.
Sometimes the packaging process involves using pre-printed labels, making it impractical to write the "best before" date in a clearly visible location. In this case, wording like "best before see bottom" or "best before see lid" might be printed on the label and the date marked in a different location as indicated.
Sometimes is used 0001.01.01 marking of expiry date that means that after opening of the product it should be used in line with instruction and can't be transferred to other person.
Use by.
Generally, foods that have a "use by" date written on the packaging must not be eaten after the specified date. This is because such foods usually go bad quickly and may be injurious to health if spoiled. It is also important to follow storage instructions carefully for these foods (for example, if they specify that the product must be refrigerated).
Bathroom products and toiletries usually state a time in months from the date the product is opened, by which they should be used. This is often indicated by a graphic of an open tub, with the number of months written inside (e.g., "12M" means use the product within 12 months of opening). Similarly, some food products say "eat within X days of opening".
Open dating.
"Open dating" is the use of a date stamped on the package of a food product to help determine how long to display the product for sale. This benefits the consumer by ensuring that the product is of best quality when sold. An open date does not supersede a use-by date, if shown, which should still be followed.
Canada.
An expiration date on food differs from a best-before date. According to the Canadian Food Inspection Agency "Expiration dates are required only on certain foods that have strict compositional and nutritional specifications which might not be met after the expiration date."
In Canada expiration dates must be used on the following food items (list and comments copied from
CFIA website):
The concern is that after the expiration date has passed, the food may not have the same nutrient content as specified on the packaging and for the listed regulated products, the nutritional content is quite important. The CFIA recommends that food should be discarded and should not be bought, sold or eaten beyond the stated expiration date. This contrasts with a best before date which is an indication of how long properly stored prepackaged food is expected to retain its "freshness, taste, nutritional value, or any other qualities claimed by the manufacturer." Passing a best before date is not necessarily a reason to discard the food. "Sell by" and "manufactured on" dates are related concepts that may guide the consumer.
Non-food items may also carry an expiration date. For example, in Canada, all children are required to be secured in an infant car seat while in a motor vehicle that is in motion. Users are required by law to follow manufacturer's directions. There is no specific law that requires an expiration date, but all Transport Canada approved car seats sold in Canada carry a manufacturer applied expiration date that ranges between 6 and 9 years from date of manufacture. The rationale is that car seats are subjected to heat, cold, sun exposure, abuse by the children, and long term storage between children, all of which can degrade the structure and function of the car seat and fail in a crash. Further, beyond the expiration date the manufacturer will no longer be monitoring the safety of the seat through testing. Transport Canada advises to destroy an expired car seat and dispose of it at a landfill or recycling facility, and never to give an expired seat to someone else or to charity.
United States.
The Food and Drug Administration in the United States notes that "[a] principle of U.S. food law is that foods in U.S. commerce must be wholesome and fit for consumption". However, the agency also states:
Most expiration dates are used as guidelines based on normal and expected handling and exposure to temperature. Use prior to the expiration date does not guarantee the safety of a food or drug, and a product is not necessarily dangerous or ineffective after the expiration date. According to the United States Department of Agriculture, "canned foods are safe indefinitely as long as they are not exposed to freezing temperatures, or temperatures above 90 °F (32.2° C). If the cans look okay, they are safe to use. Discard cans that are dented, rusted, or swollen. High-acid canned foods (tomatoes, fruits) will keep their best quality for 12 to 18 months; low-acid canned foods (meats, vegetables) for 2 to 5 years". .
"Sell by date" is a less ambiguous term for what is often referred to as an "expiration date". Most food is still edible after the expiration date. A product that has passed its shelf life might still be safe, but quality is no longer guaranteed. In most food stores, waste is minimized by using stock rotation, which involves moving products with the earliest sell by date from the warehouse to the sales area, and then to the front of the shelf, so that most shoppers will pick them up first and thus they are likely to be sold before the end of their shelf life. This is important, as consumers enjoy fresher goods, and furthermore some stores can be fined for selling out of date products; most if not all would have to mark such products down as wasted, resulting in a financial loss.
The expiration date of pharmaceuticals specifies the date the manufacturer guarantees the full potency and safety of a drug. Most medications continue to be effective and safe for a time after the expiration date. A rare exception is a case of renal tubular acidosis purportedly caused by expired tetracycline. A study conducted by the U.S. Food and Drug Administration covered over 100 drugs, prescription and over-the-counter. The study showed that about 90% of them were safe and effective as long as 15 years past their expiration dates. Joel Davis, a former FDA expiration-date compliance chief, said that with a handful of exceptions - notably nitroglycerin, insulin and some liquid antibiotics - most expired drugs are probably effective.