SPF FACT SHEET:Decoding Sun ProtectionEverything you ever wanted to know in our essential guide to SPFs
SPF Fact Sheet
SPF FACT SHEET:YOUR QUESTIONS ANSWEREDProtect your skin from harmful rays with our essential guide to SPFs

A radiant glow is always top of the agenda for summer, but there can be a fine line between looking sun-kissed and being sun-singed. A lot depends on the protection we use, but it seems many of us are baffled by the different factors and when to use them. Throw some stars, acronyms and a few enduring myths into the mix (no, a ‘base tan’ will not protect you against sunburn) and it’s no wonder we’re often left feeling confused.

The fact of the matter is, while basking in the sun offers a host of health benefits (studies have shown that natural sunlight can boost serotonin levels, lower blood pressure and strengthen bones), there is no such thing as a truly ‘safe’ tan, which makes using a product with an appropriate SPF non-negotiable. ‘The safest way to get a tan is slowly and through a sunscreen. You’ll still have some sun damage – that’s what a tan is – but you’ll have less burn,’ says consultant dermatologist Dr Nick Lowe. Put simply? Being clued-up on sun protection will ensure you and your skin have a happier, healthier summer.

SPF Fact Sheet

Make no bones about it, both UVA and UVB rays do harm to the skin but the effects they have are a little different so it’s important that you’re protected against both (hence ‘broad-spectrum’ sunscreen). An easy way to distinguish between the two is to think of UVA as the ‘ageing’ rays and UVB as the ‘burning’ ones. ’UVA are the deepest-penetrating and most ageing ultra violet rays,’ says Dr Lowe. UVB rays aren’t able to penetrate the skin as deeply thanks to their shorter wavelengths, but they causes more damage to the surface and are the cause of most skin cancers. 


The sun protection factor (SPF) is the measure of how long a sunscreen will protect you from UVB (and only UVB) rays compared to if you weren’t wearing any. A sunscreen with an SPF of 30, however, is not twice as effective as one with an SPF of 15. In fact, SPF15 filters about 93% of UVB rays, SPF30 filters 97% and SPF50 filters 98%. Layering all of these factors on top of each other will also never give you 100% coverage – only sitting indoors away from any windows wearing a wide brim hat might manage that.

SPF Fact Sheet

All skintones burn and all need a broad-spectrum, high-SPF sunscreen. If your skin is changing colour it’s being harmed – rates of melanoma among those with dark skintones are just as high as those among people with lighter skintones.


The main difference between so-called physical and chemical sunscreens is that physical sunscreens (or UV reflectors) block the sun’s rays on the surface of the skin while chemical sunscreens (or UV absorbers) absorb into the skin where they convert the sun’s rays into heat. However, Dr Lowe warns against getting too bogged down in the word ‘chemical’. ‘There’s a lot of hocus pocus about chemical vs physical sunscreens as all sunscreens are made up of chemicals,’ he says. ‘Even so-called “chemical-free” or physical sunscreens are made up of titanium dioxides and zinc oxides which are, of course, chemicals.’

In general, chemical sunscreens tend to be better for a tan while sensitive skin and rosacea sufferers often benefit from physical sunscreens as they deflect heat from the sun’s energy away from the skin.


Ideal coverage is 2 milligrams of sunscreen per square centimetre of skin (that’s at least two tablespoons worth to cover the exposed areas of the face and body) which should be applied at least 15 minutes before sun exposure and preferably before you head outdoors. Look out for easy-to-miss bits such as around shoulder straps, backs of the legs, tips of the ears, the nose, the lips and your hair parting.

Tailor your SPF to your location. Did you know, for example, that UV rays are more potent in sand and stronger in sea foam? It also pays to employ a little pre- and post-tan troubleshooting: try limiting exposure to the sun between 11am and 4pm, and adding in some antioxidant insurance in the form of a vitamin C serum which can be layered under your SPF to help neutralise damaging UV rays. And the most important sunscreen rule? Reapply, reapply, reapply! Every two hours and immediately after swimming.

Best for dark skintones

Best for sensitive skin

Best for sporty types

Best for acne-prone skin

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