How your UV-protective sunscreen works

It’s easy to apply and invisible, protecting you from the sun’s harmful rays. So how does sunscreen work? Here we answer some typical questions.

 

Why do we need sunscreen?

Sunburn is not actually caused by heat from the sun, but rather the radiation that the sun produces. The sun releases ultraviolet (UV) radiation in two different wavelengths, and each are harmful in different ways. These wavelengths are called UVA and UVB.

UVA is a longer wavelength, which penetrates deep into the skin and causes cellular damage. This exposure often leads to premature ageing, skin discolouration and wrinkles. UVB is shorter, and damages the surface of the skin.

The damage from UVB is more severe, and can cause freckles, moles, sunburn, and cancer[1][2][3][4][5]. Doctors believe that up to four out of five cases of skin cancer are directly caused by prolonged exposure to UVB rays[6].

sunscreen protects us from harmful UV radiation from the sun

 

The chemicals used in sunscreen

Titanium dioxide has been used for decades in a number of ways. But one of its greatest success stories is protecting us from the harmful effects of sun.

Sunscreens contain several chemicals designed to protect your skin. One of the most important and effective of these substances is titanium dioxide, and over time it has been improved, becoming more accomplished at the job.

 

How does titanium dioxide help?

Titanium dioxide is used to absorb UV radiation to protect the skin.

Unlike other compounds used in sunscreens, which may absorb only a part of the UV radiation, titanium dioxide is extremely efficient at protecting against all aspects of UV light that can affect skin – absorbing and scattering both UVA and UVB rays.

 

Improving how sunscreen looks

Despite the safety benefits, sunbathers often don’t want a white layer of cream spread over their bodies. It can feel uncomfortable and doesn’t look great.

Sunscreens available today can use special grades of titanium dioxide to get around this problem. In nanoparticle form it still protects by absorbing UV radiation, but unlike larger particle titanium dioxide it is transparent rather than white.

 

those with fair skin are more susceptible to sun damage

 

Safe protection from the sun

The use of nanoparticles is crucial to protect skin from harmful radiation and has been tested to ensure its use doesn’t have any harmful effects. The Danish Environmental Protection Agency (Miljøstyrelsen) tested the use of nano-sized titanium dioxide in sunscreens, finding its use to be harmless[7].

Nanoparticles of TiO2 used in sunscreens remain on the outer layer of our skin and are not absorbed into the skin or subdermal tissues when applied as a cream[8][9].

Considering the dangers of radiation, it’s clear that titanium dioxide nanoparticles can provide an invaluable protection for our skin from sun damage.