Are you applying suntan lotion incorrectly?

Sunscreen users are being urged to take more care when applying lotions in order to properly protect their skin, as temperatures continue to soar across the UK.

A new study has found that while using sun protection factor (SPF) 15 sunscreen should be enough to stop sun damage in theory, many people put on sun lotions and creams too thinly or unevenly for them to be effective.

“In reality, people need SPF 30 or 50 to be safe, say the study authors, who carried out experiments with volunteers in their lab”, reports the BBC.

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“There is no dispute that sunscreen provides important protection against the cancer-causing impact of the Sun’s ultraviolet rays,” said Professor Antony Young, who led the study at King’s College London.

“However, what this research shows is that the way sunscreen is applied plays an important role in determining how effective it is.”

How much suntan lotion should you use?

SPF ratings are “based on the assumption that a 2mg blob will cover 1 sq cm of skin”, according to BBC.

But previous research has found that users typically apply between 20% and 60% of the amount needed to achieve the advertised SPF, reports The Independent.

Factor 50 lotion applied in the typical way would, at best, provide less than half of the expected protection, the new study found.

For proper coverage, you need to apply at least six full teaspoons (36g) to cover the body of an average adult, with more than half a teaspoon each for the face, neck and the ears, and for each arm. More than one teaspoon should be applied to each leg, the chest and abdomen area, and the back.

It is also important to reapply sunscreen as required. Most lotions should be reapplied at least every two hours and immediately after swimming, says the BBC.

The British Association of Dermatologists (BAD) recommends putting on sunscreen between 15 and 30 minutes before going out into the sunshine, to give it time to dry, and topping up again shortly after heading outdoors, to cover any missed patches.

What factor suntan lotion should you go for?

The NHS states that when buying sunscreen the label “should have a sun protection factor (SPF) of at least 15 to protect against UVB and at least four-star UVA protection”. UVA, or ultraviolet A radiation, protection can also be indicated by the letters “UVA” in a circle, which indicates that it meets the European Union standard, the site adds.

Consider your surroundings too. According to BAD statistics, the reflection of the Sun’s rays can increase the power of the radiation by up to 85% in snow, 17% in sand and up to 5% in water.