So CAN you use last year’s sun cream?

How much should you really spend — and all your other burning questions answered...

Do you need different formulations for your face and body? What IS the difference between a mineral sunscreen and a chemical one? And could your sun cream be toxic to the environment? Claire Coleman answers all your questions . . .

WHY ARE SKIN CANCER RATES STILL GOING UP?

SALES of sun care products in Western Europe rose 2.1 per cent to more than £2.1billion in 2016 and we spend over £388million a year on them in the UK alone. But Cancer Research UK statistics show melanoma skin cancer is on the rise, with 15,400 people diagnosed every year.

Given that we’re all far better at slapping on sun cream than we used to be, it’s easy to doubt how well it’s protecting us.

But according to Fiona Osgun of Cancer Research UK, our expectations are to blame because we overestimate what suncream can do.

‘If you’re sunbathing to get a tan, there is no safe way to protect your skin,’ she says. ‘People think that once they’ve put sunscreen on they’re bulletproof, but it’s a false sense of security.’

The Sun Protection Factor (SPF) in your sun cream relates to UVB, the rays that burn skin. It multiplies your natural protection against burning. So if your bare skin would normally go red after ten minutes in the sun, SPF 20 will multiply that number by 20 — so if it’s applied properly, it would be about 200 minutes before your skin turned red.

Similarly, the five star system relates to UVA, the rays that have a role to play in ageing and skin cancer, and show how much protection from them you’re getting. The more stars, the better the protection provided.

But no cream gives total protection, says Fiona. ‘You also need to cover up with clothing — hats, sunglasses, something over your shoulders — and stay in the shade during the hottest part of the day.’

MINERAL OR CHEMICAL?

MINERAL sun protection usually contains zinc oxide, titanium dioxide or iron oxide, which forms a physical barrier against the sun’s rays by bouncing light off the skin.

Chemical sun filters, which are what most sun creams contain, have ingredients with names such as homosalate, octocrylene and octinoxate. They work by absorbing the sun’s UV energy and converting it into heat, which is released from the skin. Both types work but dermatologists often favour mineral protection.

‘It is less prone to causing irritation or spots,’ says dermatologist Dr Sam Bunting. ‘Chemical sun filters can break down in the sun into ingredients that may clog the skin.’

She suggests using products based on zinc oxide. ‘It has different colour properties from titanium dioxide, so you tend not to get the chalky white finish.’

COULD SUN CREAM HARM MARINE LIFE?

AN ESTIMATED 14,000 tons of sunscreen are washed into the oceans each year, which is bad for the marine environment. This year, Hawaii was the first U.S. state to pass a bill banning sunscreens containing two ingredients — oxybenzone (also known as benzophenone-3) and octinoxate (also known as octyl methoxycinnamate and ethylhexyl methoxycinnamate) — because they harm coral reefs.

Some studies have suggested these chemicals could potentially alter the gender of fish and interfere with normal biological functions of marine life.‘These UV filters tend not to be widely used in Europe because they’re not the best available,’ says Antony Young, Professor of Experimental Photobiology at St John’s Institute of Dermatology, King’s College London.

However, Piz Buin’s Tan Intensifying Sun Spray and 1 Day Long Lotion both contain oxybenzone, as do many Malibu sun creams and some Hawaiian Tropic products. You’ll find octinoxate in the P20 range. Green People and The Organic Pharmacy both have sun creams that they claim are marine-friendly.

DO ONCE-A-DAY PRODUCTS WORK?

THE general consensus is, no.

‘Lots of studies suggest they don’t actually give you all-day protection,’ says dermatologist Dr Anjali Mahto. In fact, Australia has even banned ‘once-a-day’ claims for sunscreen.

Dr Bunting adds: ‘There is concern about whether they stay on in enough quantity to deliver the protection needed.’

There is no substitute for re-applying cream every 90 minutes to two hours, and more frequently if you’ve been in the water or exercising. Expect to use about a shot glass-full to cover your body, and at least half a teaspoon for face and neck.

Research suggests the biggest impact on sun cream efficacy is how much you apply. This matters even more than which product you choose and how you apply it — and generally, people don’t apply enough.

Oh, and while Cancer Research UK advises a minimum SPF15 and four star UVA rating, go for 30+ — the higher the SPF, the more likely it is to make up for the fact that you don’t put enough on (nobody does).

DIFFERENT CREAMS FOR FACE AND BODY?

IT’S not just clever marketing — you probably do need at least two different bottles of sunscreen for your summer holiday.

‘With kids who will be in and out of the water, you want products that are more water-resistant,’ says Dr Bunting. ‘But they may cause spots if you put them on your face as they’re designed to seal skin temporarily, which can make them pore-blocking.’ Dr Mahto agrees: ‘The most important thing is to have a product you’re happy to use and re-apply — and with the face, that tends to mean a more sophisticated formulation.’

Price is no indicator of quality, but more expensive products feel and smell more luxurious, making them more pleasant to use.

There’s nothing to stop you using the same body product on you and the children, but you may prefer one that feels more indulgent and has a fragrance — which you might not want to use on children, as fragrances can cause allergic reactions. For your face, a mineral-based product is probably a better bet.

CAN I USE A GADGET INSTEAD OF CREAM?

FROM bracelets that change colour after a certain amount of sun exposure to jewellery that connects with an app and tracks your location to measure your UV dosage, ‘technical sun protection’ sounds good but has been shown to be rather unreliable.

After all, if your braceleted arm is in the shade and your face in the sun, the bracelet can’t tell when you’ve had enough sunlight. And our experts have their reservations. ‘If they encourage people to think about sun exposure, that’s great,’ says Dr Mahto. ‘But you still need to ask “Is my skin going red? Am I out of the sun when it’s hottest?” ’

CAN I USE LAST YEAR’S PRODUCTS?

IN THEORY you probably can — if the product is unopened. A sealed bottle that has been kept in a cool, dark place should be good for two years, but look at the tube or bottle and you’ll see a symbol of a jar with the lid off that will have 6M or 12M written on it. That means the maker can only guarantee the stability and efficacy of the product for six or 12 months after opening.

If the product has separated or smells funny, it’s probably no good. At best it is likely to be ineffective, at worst it may have broken down into compounds that will irritate your skin or cause allergic reactions.