Background[ edit ] Shelf life is the recommended maximum time for which products or fresh harvested produce can be stored, during which the defined quality of a specified proportion of the goods remains acceptable under expected or specified conditions of distribution, storage and display. 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. Most food is still edible after the expiration date. 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.
Some stores can be fined for selling out of date products; most if not all would have to mark such products down as wasted , resulting in a financial loss. Shelf life depends on the degradation mechanism of the specific product. Most can be influenced by several factors: Product quality is often mathematically modelled around a parameter concentration of a chemical compound, a microbiological index, or moisture content.
Bacterial contaminants are ubiquitous, and foods left unused too long will often be contaminated by substantial amounts of bacterial colonies and become dangerous to eat, leading to food poisoning. However, shelf life alone is not an accurate indicator of how long the food can safely be stored. For example, pasteurized milk can remain fresh for five days after its sell-by date if it is refrigerated properly.
However, improper storage of milk may result in bacterial contamination or spoilage before the expiration date. 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. Food and Drug Administration covered over drugs, prescription and over-the-counter.
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.
One criticism is that the U. The SLEP and FDA signed a memorandum that scientific data could not be shared with the public, public health departments, other government agencies, and drug manufacturers. Shelf-life is not to be confused with service-life defined as, A general term used to quantify the average or standard life expectancy of an item or equipment while in use.
When a shelf-life item is unpacked and introduced to mission requirements, installed into intended application, or merely left in storage, placed in pre-expended bins, or held as bench stock , shelf-life management stops and service life begins.
Cold chain Nearly all chemical reactions can occur at normal temperatures although different reactions proceed at different rates. However most reactions are accelerated by high temperatures, and the degradation of foods and pharmaceuticals is no exception.
The same applies to the breakdown of many chemical explosives into more unstable compounds. Old explosives are thus more dangerous i. Rubber products also degrade as sulphur bonds induced during vulcanization revert; this is why old rubber bands and other rubber products soften and get crispy, and lose their elasticity as they age. However, as with many rules of thumb, there are many caveats and exceptions. It is often applied in shelf life estimation, sometimes wrongly.
This is mathematically incorrect if the rule was precisely accurate the required temperature increase would be about The same is true, up to a point, of the chemical reactions of living things. They are usually catalyzed by enzymes which change reaction rates, but with no variation in catalytic action, the rule of thumb is still mostly applicable.
In the case of bacteria and fungi , the reactions needed to feed and reproduce speed up at higher temperatures, up to the point that the proteins and other compounds in their cells themselves begin to break down, or denature , so quickly that they cannot be replaced. This is why high temperatures kill bacteria and other micro-organisms: On the other hand, 'elevated' temperatures short of these result in increased growth and reproduction; if the organism is harmful, perhaps to dangerous levels.
Just as temperature increases speed up reactions, temperature decreases reduce them. Therefore, to make explosives stable for longer periods, or to keep rubber bands springy, or to force bacteria to slow down their growth, they can be cooled. That is why shelf life is generally extended by temperature control: Since such storing of such goods is temporal in nature and shelf life is dependent on the temperature controlled environment, they are also referred to as cargo even when in special storage to emphasize the inherent time-temperature sensitivity matrix.
Temperature data loggers and time temperature indicators can record the temperature history of a shipment to help estimate their remaining shelf life. When moisture content is a mechanism for product degradation, packaging with a low moisture vapor transmission rate and the use of desiccants help keep the moisture in the package within acceptable limits.
When oxidation is the primary concern, packaging with a low oxygen transmission rate and the use of oxygen absorbers can help extend the shelf life.
Produce and other products with respiration often require packaging with controlled barrier properties. The use of a modified atmosphere in the package can extend the shelf life for some products. Some active packaging is also available with antibacterial properties.
You may improve this article , discuss the issue on the talk page , or create a new article , as appropriate. The guide sets out what items must be labelled and the format of the date. However, there is no requirement that the year be in four digits.
Examples include pasteurised fresh milk, packed egg and ham sandwiches, etc. Some states restrict or forbid the sale of expired products, require expiration dates on all perishable products, or both, while other states do not. There are items in the Department of Defense DoD and the Federal Supply System that require special handling due to certain deteriorative characteristics.
These items are to be properly maintained to ensure that the customer is provided fresh, useable material. Shelf-life management for hazardous material follows the same procedures as those for any shelf-life items, except that hazardous material should receive priority processing over non-hazardous material.
Issues and guidelines concerning the acquisition, storage, handling, transportation, and disposal of hazardous material are addressed in Chapters 3 and 5 of this Manual. This Manual endorses the pollution prevention measures in DoD Instruction Appendix L serves as a quick reference index to this Manual. Freshness date[ edit ] A freshness date is the date used in the American brewing industry to indicate either the date the beer was bottled or the date before which the beer should be consumed.
It can be affected by light, air, or the action of bacteria. Although beer is not legally mandated in the United States to have a shelf life, freshness dates serve much the same purpose and are used as a marketing tool. This was not to ensure that the beer was "fresh" but to ensure that it had been aged properly.
So many breweries had rushed beer to market before it was ready when Prohibition ended, that customers were wary of getting "green" beer. The Boston Beer Company , maker of Samuel Adams , was among the first contemporary brewers to start adding freshness dates to their product line in For ten years there was a slow growth in brewers adding freshness dates to their beer. The practice rapidly grew in popularity after the Anheuser-Busch company's heavily marketed "Born-On dates" starting in Many other brewers have started adding freshness dates to their products, but there is no standard for what the date means.
For some companies, the date on the bottle or can will be the date that the beer was bottled; others have the date by which the beer should be consumed. Related concepts[ edit ] The concept of shelf life applies to other products besides food and drugs. Gasoline has a shelf life, although it is not normally necessary to display a sell-by date. Exceeding this time-frame will introduce harmful varnishes[ clarification needed ], etc.
Some glues and adhesives also have a limited storage life, and will stop working in a reliable and usable manner if their safe shelf life is exceeded. Rather different is the use of a time limit for the use of items like vouchers, gift certificates and pre-paid phone cards, so that after the displayed date the voucher etc.