You wouldn’t dream of eating food that’s gone past its ‘use-by’ date – but maybe you’re still trying to eke out a Jurassic Age mascara…. But at Beauty Bible we get many e-mails asking: how can you tell if cosmetics have gone off…?

Helpfully, though you might not even realise it, cosmetics do now generally come with a ‘Use By’ date. Thanks to a European directive, manufacturers now have to offer guidelines about how long a product can be kept after opening, for safety reasons. But you’d be forgiven for not knowing this, because the EU have made zero attempts to communicate this to the consumer!

And the trouble is, you probably need a magnifying glass (or at least some specs) to spot it on the packaging: a little symbol (it’s called a ‘pot’ symbol because it looks like a jar with the lid open), with a number beside it. ‘6’ means six months. ‘24’ means two years. And so on. (3, 6, 12 or 24 are the numbers you’ll most commonly see.) So if you open it in March, and it says ‘12’, technically it should still be good till the sun goes down on February 2009. (Before opening, products aren’t exposed to light and air, so the clock really starts ticking the minute you unscrew the lid.) And in reality, most of us hang onto make-up for longer than we should: a recent study from the College of Optometrists found that despite recommendations to throw away mascara after three to six months, 92% admit to keeping it longer!

All reputable companies put their products through a standard battery of ‘shelf-life’ challenges before putting them on the market. But it’s hard to remember when you opened a product – and this PAO (Period After Opening) date doesn’t take into account some other important factors related to ‘consumer use’. (Or ‘consumer abuse’, more like!) For instance, they don’t reflect how often you use a product, whether you leave the lid off, if it’s kept in a steamy bathroom or your car, and whether or not you wash your hands before using it. (And you should, always, as a matter of course thoroughly wash hands thoroughly before dipping a finger in any product or cleansing your face or eyes. We were horrified at one skincare launch to hear Professor Michael Cork, a respected independent dermatologist, reveal that in a study he’d carried out into eczema creams used on children by their mothers, some were infected with staphylococcus, and some with MRSA, the resistant strain of staph. And all because of poor hygiene…)

So do also rely on your eyes, nose (and common sense) to tell you if there’s a problem, and if you perceive changes, bin the product. (The only exception: eye make-up removers containing chamomile, which can go from bright blue to dingy grey in a matter of weeks; this is a natural breakdown and not harmful; it can be simply avoided by keeping it in the bathroom cabinet).

One last thing? Do an audit of your beauty kit: if you look on the packaging in your make-up kit or bathroom cabinet, and products don’t have a symbol – out with them! Because it probably means they were made before 2005, and are overdue for the bin. (Just remember to recycle packaging, wherever you can…)

Generally, though, how long should things last?

Mascara - buy a new one every six months, max – and before that, if it goes lumpy or changes texture. Remember, don’t ever loan your mascara to anyone – it’s one fast way to spread an infection.

Eye make-up - powder shadows, cream shadows and pencils should last for two to three years, but if you do suffer an eye infection at any time, get rid of what you were using then, to avoid reinfection. Liquid eyeliners should be replaced as often as mascaras – and again, neither a borrower nor a lender be.

Foundations – these are designed to go on for between one and two years, but if they’re exposed to light and changes of temperature, the oils can start to go rancid and separate before that.

Blushers – powder blushes are good almost forever (bugs can’t breed in the dry formula), but cream blushers should be replaced every year, minimum.

Nail varnish - should last for a year, but if it goes lumpy before that, get rid of it – it’ll lead to a less-than-perfect manicure, anyway, with blobbiness and bubbling. (N.B.: Supermodels keep theirs in the fridge).

Fragrance - again, your nose will tell you if it’s in perfect condition, although it should last at least a year. Fragrance can start to smell less-than-glorious if it’s exposed to sunlight, so it’s recommended to keep it in the dark, or better still the fridge. (This can be very bracing!) It’s also nice to tuck scent in your lingerie drawer.

Lipstick - 12-18 months. (You’ll be bored by it before then, anyway.)

Eye cream - can last up to a year or two, but use your nose; if it smells different, ditch it. Don’t leave it where the sun can get to it.

Sunscreen – it’s crucial to replace this every year. That may seem expensive, but the screening ingredients can lose their potency if they over-winter in your bathroom cabinet, exposing you to risk of sunburn next summer.

Facial oils – if there’s no water at all in the formula, these should last for two years, but are best kept out of sunlight to maintain optimum performance of the essential oils in the formulation.

Skin creams – natural and organic skincare may not have the same levels of preservatives as conventional creams, so you need to be extra-alert to any changes, and also extra-vigilant about introducing bacteria into products by touching them with your hands. Think: six to nine months for natural/organic; 18-24 months for everything else, at normal room temperatures or in the fridge. Bin anything if the smell changes. Likewise cleansers and toners, which should never be diluted.

And in addition, some important ‘after-care’ tips…

• Keep cosmetics away from light and heat. (Lots of beauty editors store theirs in the fridge).

• Travel with cosmetics in your hand luggage, to avoid exposing them to extremes of temperature in the hold.

• Use those dinky little spatulas and nozzle caps which come with products; they’re designed to stop you contaminating the ingredients with less-than-spotless fingers.

• Clean the spatulas often with hot water, then dry them on cotton wool. (A grubby spatula’s no better than a finger).

• Look for pump-action products – which stop air/germs getting in.

• Never water cosmetics down as you change the precise balance of preservatives added to keep a product safe.

• Keep wide-mouthed jars firmly screwed.

• Always wash and dry your hands before applying skincare or make-up.

• Keep your make-up brushes standing up in a jar with the bristles up. Suggests New York make-up artist Mollie Roncal, ‘every two weeks, wash the bristles with baby shampoo, followed by conditioner to make them nice and soft.’

DISCLAIMER: The views, opinions and information expressed in this article and on Victoriahealth.com Ltd are those of the author(s) in an editorial context. Victoriahealth.com Ltd cannot be held responsible for any errors or for any consequences arising from the use of the information contained in this editorial or anywhere else on the site. Every effort is made by the editorial and content team to see that no inaccurate or misleading information, opinion or statement appear, nor replace or constitute endorsement from medical bodies or trials unless specified. Victoriahealth.com Ltd accept no liability for the consequences of any inaccurate or misleading data, information, opinion or statement. Information on Victoriahealth.com Ltd and in the editorials is provided for informational purposes only and is not intended as a substitute for the advice provided by your physician or other healthcare professional. You should not use the information on this website or in the editorials for diagnosing or treating a health concern or disease, or for the replacement of prescription medication or other treatment.