Everything you need to know about expiry dates

Whether for budget reasons or simply trying to help save the planet, we all want to minimise food waste and make the most of our food and the products we consume. However, at the same time, we must still take care of our health. This means knowing the ins and outs of expiry and best-before dates, not only for our food, but also for skin care, cosmetics, and medications.

Here's everything you need to know about which products are safe to keep using and get more life out of, and which need to be discarded for your safety.

"Use by" dates indicate when food must be eaten by for health or safety reasons. According to Food Standards Australia New Zealand, FSANZ, "Foods should not be eaten after the use-by date and can’t legally be sold after this date because they may pose a health or safety risk." You shouldn’t eat any food that is past its "use by" date, even if it looks and smells okay.

A helpful way to remember the difference is that "use by" dates are mainly to determine the safety of food, whereas "best before" dates are mainly used to determine the food’s quality.

"Best before" dates on foods indicate when they should be eaten by before it starts deteriorating in quality. They will be safe to eat right up to this date as long as they have been stored properly.

You might see food sold in shops past its "best before" date. Legally they can still be sold as long as the food is fit for human consumption. The positive is you’ll often find such products reduced in price.

Bread differs in that they can be labelled with a "baked on" date or "baked for" date if its shelf life is less than seven days.

Interestingly, some foods that have a shelf life of two years or longer (such as canned food) don’t need to be labelled with a "best before" date. According to FSANZ, it is hard to provide an accurate guide as to how long these foods will keep. It states, "They may retain their quality for many years and are likely to be consumed well before they spoil."

The packet should also indicate any specific storage conditions required to keep the product until its "best before" or "use by" date. For example, "This cheese should be kept refrigerated".

If you grab a product at the shops and its packaging is damaged, such as with dents, leaks or tears, don’t buy it as it might be contaminated with bacteria.

All medications have an expiry date, as they are made up of chemicals that break down as time passes, which means they won’t work as effectively as they should. Health Direct, the Australian Government health information portal states, “They may also become dangerous due to a change in their chemical makeup. Taking old medicines can cause harm, or even be fatal, especially if you are taking them for a serious health condition.”

NPS MedicineWise advises discarding medicines past their expiry date. It states that while a product is stable in its container, it may become unstable once it’s opened. You should also follow storage instructions on the packaging to ensure the medications stay effective until the expiry date.

Ideally, you should talk to your GP or pharmacist about reviewing your medicines every 6-12 months, Health Direct suggests, particularly if you take more than one medication or you are taking them for a complex health condition.

It is not recommended to use cosmetics past the recommended expiry date, according to Product Safety Australia. But how can you know when they're no longer safe to use if there isn't an expiry date?

Here are some ways to check if your skin care and makeup products are still usable.

There may be a symbol on the product that shows the "period after opening." It is shown as a small number inside a small image of an open cream pot. For example, if it shows 12, it means 12 months. The number represents the number of months the manufacturer advises the preservative system in the product will be able to fight off bacteria (with maximum strength) once opened, Mecca reports. “Once that time is up, it doesn’t mean that the preservative system becomes ineffective immediately, it just means it might start to become a little bit less effective.”

Depending on the country it was manufactured a product may not show an expiry date. In these cases, try to contact the customer service department of the company that produced the cosmetics and ask for it.

Cosmetics calculator such as CheckCosmetic.net can help you determine the manufacture date of cosmetics by the batch code or lot number. You can look up your products by filling out just a few questions. It can calculate the production date and approximate expiration date from the batch code.

If both an expiry date and PAO symbol are present, the product expires whichever is reached first.

Mecca provides a general guide as to when to get rid of products if you’re unsure or can’t find the expiry date:

• Products like eyeliner and mascara that come in close and direct contact with your eyes shouldn’t be used for longer than three to six months.
• Powders can be sustained for longer and can last for one to two years.
• Cream products like foundation and lipstick tend to stay strong for up to two years too. Products in a pump or stick fare better than those in a pot, due to contamination from being opened and fingers dipping in.
• Natural and organic products contain few or no preservatives, so will typically have a shorter shelf life.

Aside from dates on the product, to determine if the product is ready for discarding, Mecca advises looking for any slight signs of change in the product, such as in colour, consistency or smell. For example, if the product starts to separate or go gluggy. An expired product will smell toxic or rancid.

Choice provides a general guide for discarding any unopened products after three years, and any opened products after six months.

In most cases, according to CheckCosmetic.net, expired cosmetics will stop working for what they were designed to do. However, it goes on to state that in extreme cases, using expired cosmetics can result in skin irritation, dermatitis, allergic reactions and infection, so it's always best to err on the side of caution and discard of any products you're unsure of.