I, and probably many of you, have a tendency to put sunscreen on as quickly as possible. Mainly because I'm lazy but also because I can't stand the sticky texture of some of the formulas. But this isn't how to apply your suncream correctly, and according to scientists, it's actually pretty dangerous.
A new study carried out by researchers at King's College London has found that the way you're putting on your sunscreen may affect how much protection you're getting from the sun. The report — which was published in the Acta Dermato-Venereologica journal — states that SPF 15 should theoretically protect the skin from sun damage. However, people should be using a sun cream with SPF 30 or 50 to ensure full protection.
However, what many may not realise is that the SPF number is practically irrelevant if you're not applying your sunscreen at the correct thickness. The SPF factor assumes that a 2 mg amount of sun cream will cover 1 cm2 of skin. So this would mean that you would need to slather on 36 g (or six big teaspoons) in order to cover your entire body.
Most people, say the experts, are putting less than half of that on, working out to roughly 0.8 mg per square cm. If you're one of them (guilty as charged), you may only be getting around 40 percent of the protection you're expecting.
Researchers enlisted 16 volunteers for the study. They split the participants into two groups of eight. Both groups applied sunscreen in varying thicknesses and were subject to UV ray exposure within 15 minutes.
One group was given a single dose of UV radiation replicating a brief exposure to sunlight. The other was given multiple doses over the course of five days, mimicking the effects of sunlight on holiday. After this, the scientists took skin biopsies in order to examine the damage done to the skin.
Those people who were in the second holiday-esque group and who applied sunscreen at the correct thickness were found to have the highest protection from the sun. This decreased the thinner the sunscreen got.
"There is no dispute that sunscreen provides important protection against the cancer-causing impact of the sun's ultraviolet rays," the study's lead researcher, Professor Antony Young, said in a statement. "However, what this research shows is that the way sunscreen is applied plays an important role in determining how effective it is."
He added: "People are typically getting much less protection than they think. For example, if you get SPF 20 and use at a lower thickness of 0.75 mg per square cm, your level of protection could be as low as SPF 4."
Well, that's not scary at all. No, it definitely is.
According to Cancer Research UK, the majority of skin cancers are caused by exposure to the sun with the damage to the skin happening potentially years before cancer even develops. Every time you burn your skin, you increase your risk.
Professor Young's recommendation for everyone is to use "a much higher SPF than [you] think is necessary." And obviously, to put it on nice and thick.
The NHS recommends applying sunscreen half an hour before going out in the sun and again just before you leave your house, hotel room, or wherever you are. It's important to remember to re-apply it after slipping into the pool or sea, after sweating, and even after drying yourself with a towel. Basically, re-apply it a lot.
Nina Goad from the British Association of Dermatologists believes that it's not wise to rely on sunscreen alone. "We should also use clothing and shade," she advised in a statement. "An extra consideration is that when we apply sunscreen, we are prone to missing patches of skin, as well as applying it too thinly."
If you're a person who can never seem to avoid sunburn, this study could just change your life. Race you to the sunscreen aisle.