what is an expiration date 
an expiration date is the last day that a consumable product such as food or medicine will be at its best quality according to the manufacturer there are important differences between expiration dates on food and those on medicine understanding an expiration datea product may have a sell by date a use by date a best by date or a do not use after date stamped on the package or the container they all have different meanings but only the do not use after date is a warning that the product should be discarded at that date because it may be unsafe ineffective or both the sell by date is meant to tell store clerks when to remove the product from the store s shelves the use by date tells consumers when the product s quality may have deteriorated the best by date merely suggests that the product s taste or texture may deteriorate after that date federal law does not require food producers to provide any of these dates on food with the sole exception of infant formula nor does the u s department of agriculture usda provide much guidance on the proper date labeling of food except for the sole exception of infant formula 2in fact the usda notes that about 30 of the american food supply is lost or wasted in part because many consumers toss out food that is still wholesome it suggests that a smell test or a taste test are more accurate indicators of edibility than a label 2expiration date stamps on food began to emerge in the 1970s when consumer advocates complained about the lack of assurances that packaged foods were still safe and edible at the time they were purchased more recently there have been complaints that the date stamps are intentionally inaccurate to persuade buyers to toss out and replace products that are still good to eat many states have adopted their own requirements so food producers now routinely mark their products regardless of their destinations so expiration dates on food can be ambiguous but expiration dates on medicine are straightforward federal regulations require prescription medicines to be date stamped over the counter medicines like aspirin cough syrup and herbal products have an expiration date often abbreviated exp followed by a month and year this indicates the date after which the manufacturer does not guarantee the potency or effectiveness of the product 5in most cases this indicates the length of time that the manufacturer is certain that the drug is safe and stable based on its own product testing that is the manufacturer does not accept liability for the product beyond that date in fact the manufacturer accepts liability for the product only until the package is opened not until its contents are used up 6 food tends to look smell or taste bad when it s no longer edible however the expiration date is the only indication that a prescription drug is still safe and effective in the late 1970s the u s food and drug administration fda mandated that all prescription and over the counter otc medical products be marked with an expiration date expiration dates for medicines are often marked exp and may be printed on the label stamped onto the packaging or both 3even small amounts of certain medications can be fatal to children or pets they should be disposed of once they pass their expiration dates it is especially important to adhere to the expiration dates of pharmaceuticals because their chemical composition can change over time making them less potent ineffective or even harmful in some cases the fda may extend the expiration date of a drug if there is a shortage of it the extended expiration date is based on stability data for the medication that has been reviewed by the fda 7dumping expired medications in the trash is not a good idea there may be disposal instructions on the drug s packaging you also can check for drug take back programs in your state or municipality in the absence of specific instructions or take back programs u s federal guidelines recommend disposing of expired or unwanted medicines by putting them in a bag or container and mixing them with coffee grounds or kitty litter some medications can be flushed 8expiration dates for foodexpiration dates on food are a different story food manufacturers date their products to notify store clerks or consumers or both when the product may no longer be at its best quality infant formula is the only food product that must carry a true expiration date under federal law the food safety and inspection service fsis an agency of the usda is the public health regulatory agency responsible for ensuring that america s supply of meat poultry and eggs is safe wholesome and correctly labeled and packaged 9manufacturers are not required to mark their products with expiration dates but if they do the labels must be truthful and not misleading a calendar date must indicate both the month and day of the month shelf stable and frozen products also must display the year in any case the date must be explained with a phrase such as best if used by 4webmd notes that eggs for example are good for three to five weeks after their sell by date 1there are no uniform or universally accepted descriptions used on food labels for open dating in the united states producers use a variety of phrases on their labels to describe quality dates 