At what time should you use sunscreen?

Sunburn: when do I need to apply sunscreen?

Skin needs effective protection from the sun. A little cream in the morning is not enough for this. Experts explain how to do it correctly and whether you can use the tube from the previous year for this.

Sun protection is mandatory not only on summer holidays, but also on weekends in the park or lake. But which sun protection factor is the right one? And how much sunscreen do I need? The most important information about sun protection at a glance.

When is sun protection even necessary?

That depends on the intensity of the sun's rays. How high it is in Germany can be found on the website of the Federal Office for Radiation Protection. From UV index three, sun protection with cream, hat and sunglasses is the trend. From level eight it is better not to be outside at all.

Which sunscreen do i need?

The most important thing is the sun protection factor. It should be at least 30, better is 50, says the Munich dermatologist Christoph Liebich. The skin type is also crucial. If you have dry skin, it is better to use a rich cream. With oily skin you switch to oil-free products. Sun protection does not have to be expensive. Every year, the product testers from Stiftung Warentest and Öko-Test find that discounter and drugstore sun creams also provide effective protection from the sun.

Can I reduce the sun protection factor over the summer?

No. The skin type stays the same - no matter how tanned someone is. Liebich recommends that anyone who wants to protect their skin always uses the same high sun protection factor.

Isn't make-up with a sun protection factor enough?

No. Liebich advises women to use the following tactic: first apply the day cream, then plenty of sunscreen. Let everything move in. Now apply the covering make-up.

How Much Sunscreen Do I Need?

The rule of thumb is: two milligrams per square centimeter of skin. For a person who is 1.80 meters tall, that's around 20 to 30 grams, says Liebich - or around three tablespoons of sunscreen. After bathing or exercising, the cream must be reapplied. Without sweating after three hours at the latest.

If you extrapolate that to a week's beach holiday, you need a lot more sunscreen than many people think: If you put 30g of sunscreen three times a day for seven days, you need 630g of sunscreen - a good three bottles.

Can I also spray myself?

The sprays are good in themselves, says Liebich. The only danger is that you will use even less than with cream. But those who spray abundantly are just as well protected as with cream.

How long can sunscreen be kept for?

As soon as you have opened it, the information on the packaging, for example the tube or can, applies. It shows how many months the cream will last after opening. The corresponding symbol is an open, round can with the information "12 M" in it, for example. That means: twelve months. However, if the bottle has been in the blazing sun, the time is shortened considerably. The cream from your last summer vacation is therefore better not brought back in your luggage.

This is also recommended by the dermatologist Professor Eckhard Breitbart. Oxygen leads to oxidation (chemical reaction) and this process leads to the fact that the ingredients change. This means that the protective function can no longer be correctly maintained, says the expert from the German Cancer Aid and chairman of the Dermatological Prevention Working Group (ADP).

In order not to lose track of exactly when you opened a sun cream, it is advisable to write the date of opening on the tube with a waterproof felt pen.

In addition: "Substances that can arise in the process could definitely be carcinogenic," says Breitbart. Although the "correct evidence" has not yet been provided. A study by French and American scientists that was published in March 2021 recently provided new evidence for the thesis: According to this, in creams with the UV protective filter octocrylene, benzophenones, which are considered to be potentially carcinogenic, have formed over time.

Sunscreen with no best-before date: what to do?

In addition, sun creams sometimes, but by no means always, have a best-before date (best before date). If this is exceeded, they should also no longer be used, advises Breitbart - even if they are still unopened.

However, there is often no concrete best-before date on the tubes. This is due to the fact that cosmetic products in the European Union (EU) only have to have a best before date if they cannot be kept for longer than 30 months, according to the Federal Office for Consumer Protection and Food Safety.

The manufacturer Nivea writes, for example, that sun protection products can be stored in a cool and dry place for at least 30 months from the date of manufacture - this applies equally to sprays and creams.

The manufacturer advises: You should dispose of the cream if it smells pungent or unusual, the consistency has changed, oil or water has settled or the contents are discolored.

How long can I stay protected in the sun?

That depends on the sun protection factor and the skin type. Someone who can stay in the sun for ten minutes without sunscreen without reddening their skin can theoretically stay in the sun for 300 minutes by a factor of 30. However, this only applies if the cream is applied correctly and continuously topped up. Incidentally, this time does not start all over again, explains Liebich. Those who apply cream with a factor of ten have to get out of the sun after 100 minutes. No matter how much he re-creams.

Do children need a special cream?

Not necessarily, says Liebich. It is crucial that they are richly creamed with a factor of 50. "Parents are responsible for that." However, special children's sun creams have the advantage that they are often fragrance-free and better tolerated. In addition, physical sun protection in the form of clothing is better than chemical protection for children.

Are children better protected with special sun protection clothing?

Since these clothes actually completely block the sun: yes. However, this only applies if it is tested textile protective clothing. Liebich warns of cheap fakes from beach stalls. Then it is better to apply lotion properly.

What else does sun protection include besides sunscreen?

Liebich strongly recommends a hat. Because: "Sun rays promote hair loss." In addition, the scalp should be well protected from the sun. In addition to the hat, sunglasses are compulsory. According to the Board of Trustees for Good Vision, it should be large enough so that no UV rays fall on the sensitive eyes from the side. In addition, the glasses need a CE mark and a suitable glare protection level. This is level three for a beach holiday and level two for a stroll through town.

Breitbart also points out that sunscreen alone is not the perfect means to keep the risk of skin cancer low. These are clothing suitable for sun protection and avoiding the sun when there is high UV exposure, for example during lunchtime.

With regard to clothing, it should be noted that they offer very different levels of UV protection. The sun protection factor of dark blue jeans is therefore around 500, while a thin white cotton T-shirt only comes to 10, explains the dermatologist Sebastian Singer in the magazine "Apotheken Umschau".

If exact UV protection values ​​are important to you, you can of course fall back on UV protective clothing. According to the report, their textile sun protection factor is reduced by frequent washing. And if you generally go for a swim with clothes on, you should consider: Wet clothes offer less protection in comparison.

Do clouds make UV protection superfluous?

A false assumption is that clouds make UV protection superfluous, explains the German Cancer Aid. In fact, clouds influence the level of UV radiation in different ways: While thunderclouds weaken them considerably, other types and combinations of clouds could even intensify them through scattering effects.

In general, the cloud sounds of Cancer Aid reduce the UV radiation intensity by only 10 to 50 percent. Especially during lunchtime, they do not offer reliable protection.

The same applies to tanned skin: Apart from the fact that this is a stress reaction of the skin, it only corresponds to a sun protection factor of around 4. Every sun cream has more.

And what do I do if I am sunburned?

Then all that helps is to cool down and wait, says Liebich. For example, poultices with quark or yoghurt have a cooling and pain-relieving effect. Those who tolerate this well can also take a pain reliever such as ASA. In severe cases, those affected have to see a doctor.