In our childhood and youth, the sunscreen – like green vegetables or the math homework – was one of the less loved things in our lives. This was partly due to the strange smell, on the other hand on the sticky consistency. Not to mention the white film on the skin. Today we see it quite differently because now we’re aware of the importance of a good sun protection for the health of our skin. And since we believe that a small refresh on how to choose the right sun protection factor will not harm anyone, here is a brief summary on the subject of SPF:
What is the sun protection factor actually and why is it so important?
The term sun protection factor was introduced in 1956 to describe how much longer you can stay in the sun when using the appropriate product without getting sunburned. Although many people assume that: Sun protection does not start on summer holidays. Surely the sun is more intense on the Mediterranean Sea or in the mountains than on a small lake in the German Sauerland, but even if we walk into the office in the morning, have lunch outside or meet for coffee in the afternoon – we are unconsciously exposed to the sun. And since the ozone layer is now as thin as ever, the sun’s rays can penetrate even more through and therefore also into our skin. If you are negligent over the years, you may end up with significant consequences – such as premature aging, wrinkles, uneven skin tone, discolouration or pigmentation, and especially skin cancer.
What is the difference between UV-A and UV-B radiation?
The sun protection factor only describes the protective effect of sunscreen against UV-B radiation. However, UV-A radiation is at least as harmful to human skin. While UV-B rays only reach the surface of the skin, UV-A rays damage the skin cells at a deeper level. Unlike damage caused by UV-B rays – which is responsible for the sunburn on the skin – it usually takes a while until cells damaged by UV-A radiation become visible. That is why sun damage to the skin does appear much later in life.
The higher the sun protection factor, the better?
How long the skin can protect itself differs depending on the skin type, but usually ranges between ten (for very light skin types) and 30 minutes (for Mediterranean skin types). According to the formula self-protection time x SPF = the possible time to stay in the sun per day without sunburn, a mixed type with 20 minutes self-protection time and a sunscreen with SPF 20 is likely to stay in the sun for 400 minutes (just under six hours). In order for the formula to apply, just as much cream must be applied as in the test lab: 2 milligrams per square centimeter. Since most of us do not apply enough sunscreen, the protective effect is reduced by 30 to 50 percent. When it comes to the sunscreen, rather a larger amount should be applied. In numbers, that means a teaspoon of cream for the face and two tablespoons for the body. And which SPF is the right one? In Europe, we should choose a SPF between 20 and 30, because it holds over 95 percent of the radiation. A low sun protection factor is only suitable for already tanned skin. But again, it’s safe to say, so rather take something more SPF than regret it later.
More about Light and Shadow
Light dictionary: The most important basic parameters of lighting technology Luminous flux, luminous intensity, light color - the basic parameters of lighting technology are often associated with big question marks. We bring light into the dark and clarify the...
Direct light vs indirect light: which type of light is suitable for what? The concept of lighting planning is aimed at individual lighting systems that are based on the most demanding task in the room: equipping the room with the appropriate light...
More well-being with biologically effective light When it comes to Human Centric Lighting or HCL, people and their well-being are the focus of lighting design. In light planning, therefore, it’s important to ensure that people feel comfortable in their...