Cosmetic shelf life - 5 useful facts

But that doesn't mean you should keep them for donkey's years! A use by date is not obligatory for products formulated to last less than 30 months once they've been opened. If they last more than 30 months, you'll find a use by date (i.e. 'once opened, use by February 2018' or similar). What's more, products that don't deteriorate won't feature a use by date. These include single use samples, products that are fully protected (aerosols) and those that don't go off when opened (perfumes). So don't worry if you can't find a use by date on a treatment!

What if you apply a product after its use by date? Well, it won't do you any major harm, but the treatment may be less effective or pleasant to use - perfumes may smell a bit stagnant or creams may harden. So, even though there's no health risk, it's still worth using up your treatments before the stated date.

Keeping an eye on the use by date is useful, but there are other ways to extend your product's 'shelf life'.- Close your products after using them - if they come in to contact with the air their perfume or texture, for example, could change.- Don't expose your products to direct sunlight- Keep them in a cool place, away from radiators and other sources of heat (south-facing windows, rear deck of a car...).

It's still useful to know the date, for example if your cream will be at its best for a year after opening. It means we can gauge how much and when to use a product - daily, at night only, during summer... But that's often a hitch - if we can't remember when we opened a product, then the use by date is of no real benefit. However, you can always write down the date you opened a treatment on its label!

Don't sunscreens have a 6 month expiry date? Shouldn't I open mine straight away, even if summer's a mile off? No! If your product is kept unopened and stored correctly (see above) it can stay in its drawer for 36 months. If you can't remember when you bought it, you can call the manufacturer's helpline - the product code contains information on when the product was made! As the saying goes, waste not, want not!