What it means
Shelf life is the period during which a product is expected to remain suitable for its intended use when stored as specified, and suitability may concern safety, potency, quality, appearance or performance. A shelf-life date is not independent of storage conditions, because heat, light, humidity or an opened package can change how long an item remains usable.
Other goods also deteriorate: cosmetics may change texture or microbial stability, chemicals may lose effectiveness and batteries may lose capacity. A food label may use a use-by date for safety and a best-before date for quality, under the relevant local rules, and UK government guidance explains that distinction in its jurisdiction.
A business should not treat those labels as interchangeable or apply UK wording to every country, and it should check the category and local requirements before selling or relabelling food near a date. Conversely, a best-before date passing does not always make a food item legally unsafe in the same way a use-by date can.
Medicine expiry dates have a different purpose and basis, since the US FDA describes expiration dating as supported by stability testing and proper storage conditions. An expired medicine should not be treated as a routine discount item like some durable goods, and pharmacies and healthcare providers need product-specific rules for quarantine, returns and disposal.
Some products have a period-after-opening rule rather than only a sealed-package date, so read the manufacturer's instructions and applicable law, because a general "two years" assumption for a whole product category is unsafe. Inventory records should capture batch or lot number and relevant dates, because two deliveries of the same item may expire at different times.
"First expired, first out" can be a practical picking rule when stock is otherwise usable, but it is not permission to sell an expired product, and quality holds and recalls override normal stock rotation. Storage controls preserve the stated shelf life: a product labelled for refrigeration may lose suitability after a temperature excursion even if its printed date is months away, so record temperatures, investigate out-of-range periods, and do not simply put the goods back in the cold room and reset the clock.
Purchasing decisions affect expiry losses, because a bulk discount can look attractive but cause write-offs if demand is too low. A product arriving with only two months of remaining life has a different economic value from one with a year, so agree minimum remaining shelf life in supplier terms where appropriate and forecast sales by batch life and supplier lead time.
A useful illustrative metric is expired-stock write-off value divided by stock purchased in a comparable period: if expired stock cost $30,000 and purchases cost $1 million, the ratio is 3%, though it needs a consistent cost basis and does not measure spoilage before expiry, theft or damage. Stock near expiry may be discounted when lawful and safe, provided the price cut covers handling, marketing and disposal alternatives and no pressure is created to sell unsafe or non-compliant goods.
A donation also needs product and recipient suitability, so it is not a workaround for expiry rules. Finance and operations should agree how to value ageing stock, since the IAS 2 lower-of-cost-and-net-realisable-value principle may require a write-down before the printed date if expected sale proceeds fall below cost.
In practice
Real-world examples.
Example
A supermarket marks down dairy products two days before their use-by date, where the rules allow. The discount recovers part of the cost and cuts waste, and the date is respected strictly, so nothing is sold after it. The store compares the markdown loss with the cost of writing the stock off completely.
Example
A pharmacy checks its shelves monthly for medicines approaching expiry and removes expired items into a quarantine area. Records show the lot number and disposal route for each item. Expired medicine is never sold at a discount.
Example
A cosmetics brand reviews its warehouse and finds a batch of creams past its period-after-opening and sealed dates. Finance writes the stock off and the buying team reduces the next order size. The brand also asks suppliers for fresher deliveries.
Formula
Calculation
Expiry write-off rate = Value of expired stock / Total stock purchased x 100
Worked example: a fictional grocer wrote off $30,000 of expired stock in a year in which it purchased $1,000,000 of stock. The write-off rate is 30,000 / 1,000,000 x 100 = 3%.
If a smaller order policy cut expired stock to $20,000 on the same purchases, the rate would be 20,000 / 1,000,000 x 100 = 2%, a saving of $10,000 before allowing for any extra stockouts.Case study
Seen in the real world.
This illustrative and entirely fictional case follows Bloom Organic Foods, an invented grocer with frequent expiry write-offs. It records lot dates, orders smaller quantities where viable and uses first-expired-first-out for usable stock. Bloom measures waste and stockouts together, because cutting order sizes too far would lose sales. It reviews the write-off rate each month against a target, and does not assume any particular percentage reduction in advance.
Watch out
Common mistakes.
- Buying bulk quantities without checking remaining usable life and demand.
- Ignoring storage conditions after a temperature excursion.
- Treating use-by, best-before and medicine expiry as equivalent dates.
Questions
People also ask.
What is shelf life?
The period an item remains suitable under its stated storage conditions.
How is it managed?
Track lots and dates, store correctly and rotate usable stock while monitoring demand.
What happens to expired stock?
Follow product-specific safety, legal, return and disposal rules; do not assume every expired item has the same treatment.
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