To protect the skin, sunscreen uses UV filters that absorb radiation from the sun. When a sunscreen is exposed to this radiation, it can alter the chemical structure of the UV filters, thus degrading their protective capabilities.

Chemical filters work by absorbing UV light and converting it to higher wavelength rays that are less harmful to the skin. In general, the higher the SPF number of your sunscreen, the greater the protection, so an SPF 6 or 10 offers low protection, SPF 15, 20 or 25 offers medium protection, SPF 30 or 50 offers high protection, and SPF 50+ offers very high protection. This is measured using a standardised test. Almost all* PIZ BUIN ® sun protection products range from being water resistant to extra water resistant like our PIZ BUIN WET SKIN ® Transparent Sun Spray. Apply sunscreen at least 20 minutes before going out in the sun to allow maximum absorption and protection.The Sun Protection Factor (SPF) specified on your bottle of sunscreen tells you how much protection your sunscreen offers against UVB rays. If you don't protect yourself from high doses of UV rays, these rays will start penetrating the layers of the skin. Eventually, blood vessels below the skin's surface will expand and leak fluids, causing inflammation and redness. Sunburn normally first appears 2-6 hours after the start of exposure, reaches its maximum intensity within 24-36 hours and disappears after 3-5 days. Sun exposure plays a major role in the skin's ageing process. Up to 90% of all visible signs of ageing can be attributed to the harmful effects of sun exposure. The key technology used in any sunscreen is the UV filter. UV filters can be either chemical or physical. Tanning starts 3-5 days after sun exposure, when special skin cells called melanocytes start synthesising melanin, the body'™s natural tanning pigment. Melanin is then transferred to neighbouring cells called keratinocytes, which are the main cell type in the epidermis or upper layer of your skin. Unlike immediate pigmentation, actual tanning does help protect against the harmful effects of UV radiation. Tanning fades progressively, but remember that people with a natural suntan also need to apply sunscreen, as a tan does not provide sufficient protection from UV exposure.

Different skin types react to the sun in different ways, so the type of skin you have influences how long you can stay in the sun and what types of sunscreen you need. Physical filters reflect, transmit or partially absorb light and can protect against both UVA and UVB radiation. The two most common physical filters are titanium dioxide and zinc oxide. A sunscreen with broad-spectrum protection means it has the ability to protect against the harmful effects of both UVA (ageing rays) and UVB (burning rays). To be classified as offering broad-spectrum protection, a sunscreen product needs to absorb or reflect at least 90% of the UV rays from the 290 to 400 nanometres (nm) wavelength range. The first colour-related effect of exposure to the sun is known as "œimmediate pigmentation", or a colouring that appears during exposure and disappears within 2 hours. Caused by UVA and visible light, immediate pigmentation does not protect against sunburn.Ultraviolet (UV) rays are invisible and are divided into UVA, UVB and UVC rays. UVA rays cause long-term skin damage, including skin cancer and premature skin ageing, while UVB rays are the main cause of sunburn. Approximately 10 times more UVA rays reach the earth's surface than UVB rays. UVC rays are absorbed by the earth's atmosphere and don'™t affect the skin. The SPF number indicates how many times longer you can stay in the sun before starting to burn. The way it works is that you take the number of minutes it normally takes your skin to burn in the sun with no protection (let'™s say 15 minutes). Then, you multiply that number by the SPF number (in this case, Factor 6). Since 15 x 6 = 90, you should have 90 minutes before you start to get a sun burn. In other words, the higher the SPF the greater the protection of your sunscreen. But remember these are theoretical values. In reality, the time depends, among other factors, on your skin phototype and the local UV intensity. Quite the reverse is true. Although your skin changes colour more slowly when you're wearing sunscreen, the resulting tan will be better and longer-lasting because the sunscreen will prevent your skin from burning and peeling. Some PIZ BUIN ® products even contain special ingredients that stimulate the natural production and the even distribution of tanning pigments in the skin. Try to avoid intense midday sun from 11:00am and 3:00pm during the summer months or when on holiday in tropical countries. Protect children. Children are particularly vulnerable to the effects of UV radiation and often spend more time outdoors than adults. Parents should take special care to protect them from the sun using protective clothing, hats, sunglasses and sunscreen. Keep babies and young children out of direct sunlight.

It'™s important that your sunscreen is water resistant when you go swimming because UV radiation half a metre below the surface of water is still 40% as intense as it is on the surface. You also need to protect the part of your body that'™s above the surface, as water reflects some 25% of UV radiation and can intensify the harmful effects.A "photostable" sunscreen is able to withstand the effects of UV exposure better, so it keeps its level of protection. To choose the right SPF, you need to consider several factors. The most important of these is your skin'™s phototype, which includes the colour of your skin before exposure to the sun, your hair and eye colour and other factors. You also need to think about where you are going on holiday and what time of year it is. The sun provides the earth with life-giving energy and is the major factor in determining the earth's climate and weather. The sun not only sends visible light to the earth but also invisible radiation that can have a negative impact on our health if received in doses that are too high. Skin cancer, or malignant melanoma, appears to be caused by damage to the DNA structure of skin cells that are exposed to the sun —“ with just 5% of all carcinomas occurring on areas of the skin that are not exposed. Damage to these skin cells leads to the growth of degenerated cells that in turn result in cancer. In Europe, skin cancer is far more prevalent in the north, where people'™s skin tends to contain less pigmentation.