What is a sunscreen?
Sunscreen, sun cream or sunblock is essentially a liquid that's applied to skin to help prevent sunburn. It contains ingredients that either absorb, reflect or scatter UV rays that can cause damage to the skin, enabling us to sit outside and enjoy the weather without the dreaded burning sensation. Effective in helping to prevent skin cancer caused by UVB rays, sunscreen should be worn whenever skin is exposed to sunlight.
Why does the skin tan?
The dark pigment that gives the skin its natural colour is called melanin. After our skin is exposed to sunlight, the skin produces more melanin to try to absorb further UV radiation, and so the skin becomes darker. A tan is actually a sign that the skin has been damaged and is trying to protect itself - so not necessarily a good thing!
What is SPF?
Sun Protection Factor - a technical and scientific measure of the effectiveness of the sunscreen. The higher the SPF, the higher the protection on the skin from damaging UVA and UVB rays. In the simplest of terms, SPF is the amount of UV radiation required to cause sunburn on skin with the sunscreen on, as a multiple of the amount required without the sunscreen. There's a common calculation that if you're wearing SPF 30 and normally burn after 15 minutes, that the sunscreen would therefore allow you to sit in the sun for over 7 hours (30 x 15 minutes.) However, the major flaw in this is that the intensity of the sun's rays varies throughout the day, so there's no guarantee how long the SPF will remain effective; it's always better to be safe than sorry and re-apply!
What SPF factor should I wear?
This really is the million dollar question; no one answer will suit all. The effectiveness of a sunscreen will depend on your skin type, the amount you apply, the frequency of application and if you've been exposed to water. I'm in the firm belief that you should wear a minimum of SPF15 if you're just going about your business on a sunny day, increasing this to a minimum of SPF30 if you're actively sunbathing or on holiday. Once the damage has been done it's irreversible, so it's better to slap on the lotion now rather than pay for it with chemotherapy ten years down the line.
What is the minimum and maximum SPF?
At the moment the minimum SPF readily available in the UK is SPF8, although in rare instances lower factors are available. However, I wouldn't recommend going any lower than SPF15 to ensure your skin has an adequate level of protection. If you are searching for a lower factor, make sure the number has precursor of 'SPF': a few brands are very sneaky and include low numbers on their packaging when they have no scientific SPF value at all. The maximum SPF in the UK is SPF50 as there's no current scientific evidence of the effectiveness over this level; historically SPFs were available up to the value of 100, but they have since been removed from the market.
When do I need to wear SPF?
There's a common misconception that sunscreen should only see the light of day when you're packing your case for Marbella, when in actual fact it should be worn daily. A large number of foundations, moisturisers and BB Creams now have added SPF to help protect the skin from UV rays when you don't even realise you're being exposed to them. Although many cosmetic products contain SPF15, because they're applied so thinly and smudge off easily throughout the day, the realistic level is more around the SPF5 mark. Wherever possible you should add a light layer of sunscreen under your makeup.
How should I apply my SPF?
Studies have found that most people apply less than half of the amount required to provide the level of protection indicated on the packaging. When applying SPF, make sure you're covering all areas of your body with a relatively thick layer of lotion, waiting enough time (roughly 30mins) for the skin to absorb the product and enable it to start working. Make sure you re-apply after you've been for a swim, rolled around in the sand or got your sweat on - anything that can rub off the formula will mean you should re-apply straight away, as well as every 2-3hrs to ensure you're fully protected. In scientific tests six full teaspoons of sunscreen are used to test the efficiency of the SPF, so this should be the amount roughly used on a full size adult. (Although taking a spoon to the beach and measuring may look a bit strange.)
How do I know what I'm buying?
The EU guidelines have enabled consumers to make a more informed and educated choice when buying their suncare. On every bottle there should be a clear SPF number, an indication of low/medium/high protection and a 'star' rating, which shows the level of UVA vs UVB protection (the more even the protection, the higher the stars.) When looking for a sunscreen you need to ensure you're covering all three bases: go for a high SPF, a high classification and a high number of stars. Stay away from oils altogether unless you want to be fried like last Christmas' turkey.
Wearing sunscreen is really important, so even if this post helps one more person understand why they should be applying it then my job is done. If you would like to find out more about suncare, skincare and Sun Awareness Week, then visit the British Association of Dermatologist's website.