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Sun Protection - Basic Knowledge

Why do you need to protect yourself from the sun at all?

The sun's rays have a broad spectrum. Rays of wavelengths 280 – 400 nanometres are called UV rays. They can damage the sensitive DNA in human tissue and since the skin is the first organ they hit, the skin is particularly at risk.

What is the difference between UV-A- and UV-B- rays?

The shorter the wavelength, the more energetic the radiation. -Rays from 280 – 320 nanometres are called UV-B- rays and rays from 320 – 400 nanometres are called UV-A- rays. UV-B- rays only penetrate the epidermis and can cause sunburn as acute damage and skin cancer as chronic damage. UV-A- rays penetrate deeper into the dermis and do not cause acute damage, but chronically they can cause massive damage to the connective tissue, i.e. to the elastic and collagen fibres, and can also lead to skin cancer. UV-A- rays are the main cause of sun-induced skin ageing (photoaging). Good UV protection must therefore always be directed against UV-B- and UV-A- rays.

How can you protect yourself well from the sun?

1. Indem man die Sonne meidet
2. Durch Textilien, die undurchlässig für UV-Strahlen sind
3. by using sunscreens with chemical or physical (mineral) filters. Chemical filters absorb the energy of UV rays and convert it into heat. Physical UV filters such as titanium dioxide or zinc oxide reflect the UV radiation.

What should the level of the chosen UV protection filter depend on?

1. the skin type
2. the degree to which the skin is accustomed to the sun
3. the altitude above sea level
4. proximity to the equator
5. personal risk profile (own or family history of skin cancer, number of moles)
6. the time of day and the season
7. the duration of the planned stay in the sun
8. reflective objects in the immediate vicinity (e.g. water or snow).

Should day creams routinely contain UV protection filters?

There are different points of view on this. I do not think the routine use of chemical or physical filter systems in day creams is right. Chemical or physical filters should only be applied if a significant stay in the sun is really planned. If you go to the office in the morning and back home in the evening, you don't need to apply sunscreen. However, I recommend always having a sunscreen in your handbag just in case.

When should sunscreen be applied?

If a stay in the sun is planned, the sunscreen is applied 10 – 20 minutes before going into the sun. If the stay in the sun starts early in the morning, the sunscreen can also be applied directly in the morning after care. To avoid over-saturating the skin or overloading it with product, the sunscreen cream can also replace the skincare cream if necessary.

How much sunscreen should be used?

The rule of thumb is 2 mg of cream per cm2 Haut. Dies entspricht 40 Gramm für den ganzen Körper bzw. entsprechend weniger, sofern nur ausgewählte Regionen wie Gesicht geschützt werden sollen.

What high should the SPF (sun protection filter) be?

The SPF always refers to UV-B rays because these redden the skin, cause sunburn and therefore make it easy to measure the effectiveness of UV protection filters. The SPF says by what time factor you can increase your stay in the sun before you turn red. If you are unprotected and turn red after 10 minutes in the sun, you will only turn red after 100 minutes with an SPF of 10. An SPF of 30 or more is called a blocker. Higher factors usually provide only marginal further protection. An SPF of 100 is a marketing concept without rationale for everyday use. The protective effect of a correctly applied SPF 30 is clearly higher than that of an incorrectly (too small amount) applied SPF 50. So anyone who correctly applies a sunscreen with an SPF of 50, whose filters also protect well against the longer-wave UV-A rays, is considered to be effectively protected. Proper application means 2 mg of sunscreen per cm2 of skin, corresponding to 40 grams of cream for the whole body (see above). However, effective protection does not exempt you from the points listed above, which must be considered every time you spend time in the sun.

How often should I reapply the cream?

When doing sports (sweating) or after swimming, it goes without saying that you have to reapply the cream appropriately. This is common sense. There are no so-called waterproof sunscreens. The corresponding declarations are not rational. It is also important to know that repeated application does not increase the SPF. So if you put on SPF 20 twice in a row, you obviously won't have SPF 40 protection.

What should I do if I get too much sun?

1. get out of the sun
2. cool down and apply light skin-soothing lotions or, in the case of severe sunburn, cortisone creams for a short time.
3. possibly take painkilling or anti-inflammatory medication internally (e.g. aspirin or ibuprofen).
4. if necessary, seek medical care and, in the further course, have skin checks to exclude or detect significant skin damage at an early stage.

Doesn't effective sun protection prevent the formation of vitamin D?

That is correct. Effective UV protection prevents the skin's own vitamin D production, which is stimulated by UV-B- rays. So if you don't take the opportunity to spend short periods of time outdoors without protection, and if you don't eat any foods containing vitamin D (e.g. milk, eggs, butter, fish), you should have your vitamin D level measured. If the level is too low, vitamin D should definitely be taken once a week in the form of a capsule.

What is Octocrylene?

Octocrylene is a commonly used UV filter. Sunscreens containing octocrylene should not be used for more than one season, as octocrylene can break down over time into the potentially carcinogenic benzophenones. Some South Sea countries, such as Palau, have banned octocrylene altogether because it may also damage coral reefs. Degradation products of octocrylenes probably also have harmful effects on the endocrine system.

What does Coral Reef Safe mean?

The substances oxybenzone and octinoxate, which are often contained in sunscreen products, can damage coral reefs. Therefore, to protect sensitive marine ecosystems, the US state of Hawaii passed a law effective from 1st of January 2021 that prohibits the sale of sunscreen products containing these ingredients there. Octocrylene will be added to the list of banned ingredients on 1st of January 2023. Sunscreen products that are free of the respective ingredients will be declared as “coral reef safe”.

What is the most important thing when dealing with the sun?