The Truth About Reapplication and Pre-Tanning

With the arrival of summer, warm days lure us to enjoy the outdoors. As always, myths about sunscreen are circulating.

Does a higher sun protection factor (SPF) offer better protection? Can a vegan diet protect your skin? Does reapplying sunscreen prolong its effectiveness? This fact check reveals the truth.

Repeated application prolongs sun protection:

That’s true, but only to a certain extent

The German Agency for Radiation Protection (BfS) recommends applying sunscreen 20 to 30 minutes before sun exposure. To maintain the protective effect, it is essential to reapply regularly: “At least every two hours and especially after swimming and toweling.”

However, Munich dermatologist Christoph Liebich explains that there is still a limit to how much sun you can tolerate, no matter how much you reapply.

“For example, if you use a sunscreen with SPF 10 and have a natural protection time of 10 minutes, your total protection lasts for 100 minutes. After that, reapplying SPF 10 or even SPF 50 won’t help,” Liebich explains.

In principle, the time in which you are protected is over once your skin has absorbed enough radiation. And yet: to make that time as long as possible, you should regularly reapply sunscreen.

It is especially important to apply enough sunscreen from the start. Experts in radiation protection say the recommended amount is two milligrams per square centimeter of skin, which is about four level tablespoons for the entire body of an adult.

A day cream is sufficient as light protection against the sun:

In some cases that is true

For a day cream to provide effective sun protection, it must contain an ultraviolet (UV) filter. Without this, there is no sun protection, says Kerstin Effers, environmental and health officer.

The SPF must be clearly stated on the packaging. “Without this information, consumers cannot judge the level of protection,” she says. Experts recommend choosing day creams with a high SPF.

It is also crucial to use enough day cream, just as you would with sunscreen. Dermatologist Liebich warns that some people may not apply enough expensive creams to their face, because they see them as luxury products.

“If you don’t apply the recommended amount, even a high SPF won’t provide adequate protection,” Liebich explains. If you’re unsure whether you need to use enough day cream, it’s better to opt for a classic sunscreen.

‘Pre-tanning’ in a sunbed protects the skin:

Incorrect

When exposed to the sun or tanning beds, the skin is exposed to ultraviolet (UV) radiation. This radiation is divided into three types: UVA, UVB and UVC.

UVA radiation penetrates the dermis, UVB radiation only affects the epidermis and UVC radiation is blocked by the ozone layer.

Liebich explains that tanning beds provide a “base tan” that offers no real protection. The light in tanning beds consists mainly of UVA rays, which create a quick but temporary tan, while UVB rays are often filtered out.

“UVB rays are necessary to build up protection, but they are prohibited in sunbeds,” says Liebich.

Tanning in a sunbed beforehand leads to extra exposure to radiation. That is why sunbeds are prohibited for people under 18. “Every extra radiation is harmful,” Liebich emphasizes.

A vegan diet protects against sunburn:

WHERE

The idea of ​​protecting yourself from tanning beds by following a vegan diet is appealing, but experts say it’s not enough.

According to the German Pharmacists Association (Abda), vitamin A and beta-carotene from healthy food can naturally protect the skin. However, they are not sufficient to prevent sunburn, especially when the UV index is high.

Beta-carotene, found in abundance in fruits and vegetables, helps protect the skin by acting as a secondary plant pigment.

Dermatologist Liebich explains that eating these foods can protect your skin from sunburn to some extent. However, he adds that sunscreen should always be the primary means of protection, as diet alone cannot provide adequate protection.

Sunscreen has a shelf life:

WHERE

Sunscreen can indeed expire and lose its effectiveness over time, making it important not to keep it for too long. Reduced UV protection can lead to sunburn in the short term and increase the risk of skin cancer in the long term.

Manufacturers indicate the recommended period of use of sunscreen after opening with a small symbol such as ’12M’ (which stands for 12 months). This symbol is usually found on the packaging.

It is helpful to write the opening date on the bottle to keep track of its shelf life. In addition, long-term storage can cause benzophenone, a potential carcinogen, to form in sunscreens containing octocrylene, which protects against UVB radiation.

Researchers in a study for the American Chemical Society found that benzophenone gradually builds up as sunscreen ages, even in unopened packages. This underscores the importance of replacing sunscreen annually to ensure its safety and effectiveness.

Sunbeds offer a "basic brown" which does not provide any real protection against the sun. Felix Kästle/dpaSunbeds offer a "basic brown" which does not provide any real protection against the sun. Felix Kästle/dpa

Sunbeds provide a “basic tan” that offers no real protection from the sun. Felix Kästle/dpa

It is important to apply enough sunscreen before going out in the sun. It is also important to reapply it regularly, but experts say there is still a limit to how long you can stay in the sun with sunscreen. Annette Riedl/dpaIt is important to apply enough sunscreen before going out in the sun. It is also important to reapply it regularly, but experts say there is still a limit to how long you can stay in the sun with sunscreen. Annette Riedl/dpa

It is important to apply enough sunscreen before going out in the sun. It is also important to reapply it regularly, but experts say there is still a limit to how long you can stay in the sun with sunscreen. Annette Riedl/dpa

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