Are sunscreens safe?

If used correctly, sunscreens are a good way of preventing sunburn. And yet, some studies have found that sunscreen users are not less likely to develop melanoma skin cancer.

This is almost certainly because many people do not use sunscreen in the right way. Studies have found that people put on much less sunscreen than they should. They also tend to use sunscreen as an excuse to stay out for longer in the sun and avoid other measures like covering up with clothes or spending time in the shade.

Because of this, many sunscreen users actually end up getting even more exposure to ultraviolet (UV) radiation from the sun than they would have done otherwise.

This is why it is very important to apply sunscreen correctly, generously and regularly.

One study suggested that when sunscreen chemicals are absorbed into the skin and exposed to ultraviolet (UV) radiation, they can produce molecules called ‘free radicals’. These have the potential to damage DNA.

This study only looked at cultured skin cells in a laboratory setting, so it is too early to say for sure if the same thing happens in real people.

And even so, the study only found a problem if sunscreen is not used properly. The researchers themselves said that there is no danger if sunscreen is used generously and reapplied regularly when out in the sun.

Many sunscreens use titanium dioxide and zinc oxide to reflect UV radiation away from the skin. These are called “inorganic sunscreens” or “sunblocks”.

Previously, these products were very difficult to apply and left a noticeable white sheen. This meant that people would either stay away from them or put on much less than they were meant to.

Recently, manufacturers have got round this problem by using very small particles of these chemicals, known as nanoparticles. Because they are so small, they make the sunscreen transparent on the skin and much easier to put on. They also provide excellent protection against both UVA and UVB - the two types of UV radiation that can damage our skin cells.

Some people have raised concerns about nanoparticles in sunscreens, especially if they are absorbed into the skin. However, this is unlikely to happen in practice. Titanium dioxide and zinc oxide cannot actually penetrate into the layers of the skin that contain living cells. Several studies have tested this and found that these chemicals sit on the top layer of skin.

Despite these concerns, sunscreens are still a safe way of preventing sunburn provided that they are used correctly.

It is important to remember that sunscreen will not protect us completely from sun damage on its own. This is why we recommend using sunscreens together with shade or clothing to avoiding burning in the sun.