Cosmetic products will remain safe and fit for their purpose for a long time provided they are stored under suitable conditions and not subjected to extreme temperatures. To ensure the maximum durability of cosmetic products, they should be stored in a cool, dry place, away from direct sunlight and with the lids firmly closed.
It is important to avoid contaminating the products during normal use and so hands should be clean before putting fingers into products and the sharing of cosmetics is not encouraged.
Always read the instructions carefully; including any warnings for use
Keep lids on products when not in use and use the product within the recommended time
Avoid storing your products in the direct sunlight or near sources of heat and chose dry, cool (but not freezing) storage areas where possible
Never dilute products or mix with other products (unless directed to do so by the product instructions)
Apply cosmetics with clean hands or an applicator and routinely wash all applicators thoroughly with soap, detergent or a mild shampoo
Allow applicators to dry thoroughly before use
Avoid sharing your personal cosmetic products with another person
Once opened, cosmetic products become exposed to dirt and microorganisms (bacteria, yeasts and moulds) that are found in the air, on the skin and on applicators and brushes. Microorganisms can get into products where they may be able live and grow.
It is difficult to avoid getting some microorganisms in an open product and so ingredients called preservatives are added to help kill the microorganisms before they become dangerous. Read more on preservatives.
However, if a product becomes heavily contaminated, this may mean that you can get irritation of the skin or even an infection if the product is then used around the eyes or on your skin. So it is a good idea to check your products regularly. They are still safe to use.
Most products are made to last a long time, although it is not always clear just how long 'a long time' is. If a product has a limited shelf life (less than 30 months - two and a half years) it is required to be labelled with a 'best before' date.
"Best before" dating is not common as most cosmetic products are formulated to ensure they have a long shelf life.
Durable cosmetics, those with a shelf life of at least 30 months, are in the majority. Even so, some consumers want to know how long an opened product can be kept.
A symbol introduced by the industry in conjunction with European Union guidelines recommends the length of time a product remains useable after opening. This period is referred to as the 'period after opening' (PAO). The period is given as a number of months and is marked with a letter 'M' under or within the 'open jar' symbol. When a PAO symbol is required this will appear on the product itself and on the outside packaging.
In practice, most cosmetic and personal care products are formulated to ensure that they are safe to use and have a shelf-life which far exceeds the normal time it would take to use the product up.
If a product has not been stored properly, for example it has been left with the lid off for long periods of time, the product may 'go off' before either the best before date or the period after opening has passed. It is easy to spot this as these products may be discoloured, smell different or look unusual (lumpy rather than smooth for example). If this is the case, the product should not be used as they will certainly be unpleasant, might not do their job properly or could be a risk to someone whose skin is not healthy (cut or sunburnt skin for example).
With correct storage and handling, cosmetic products should remain in good condition for their expected life. However, if a product discolours or has an unpleasant smell, it should be discarded since this indicates the product is not as it should be.