What's in Sunscreen?

There is no question that sun protection is essential and will become more and more important in the future. But what's in sunscreen? Are all active ingredients that get into our bloodstream through the skin with sunscreen and the like, harmless? Or are there any unwanted side effects? Because this is not so clear with many products, the American Food and Drug Administration (FDA) proposed a regulation calling on manufacturers to take a closer look at the absorption rate of their ingredients and to disclose how much of which substance arrives in our body. This regulation should come into force in November 2020.

A distinction must be made between the ingredients of physical and chemical sun creams. The two fundamentally different ways in which sunscreens achieve their protective function both have their advantages and disadvantages. if you the corresponding article haven't read about it yet, we recommend doing so for a better understanding.

Physical sun creams: toxic nanoparticles

The idea of physical sunscreens is to create a reflective protective layer on the skin. Normally, however, this leads to an unsightly white layer when applied correctly. To make the sunscreen less visible, physical sunscreen manufacturers have made the titanium dioxide and zinc oxide particles extremely small. Because the particles are then less than 100 nanometers in size, they are called nanoparticles. The main concern about such ingredients comes from the fact that they can penetrate and build up in the body. The legitimate question: "Is that bad?" cannot yet be answered, because we simply still don't know enough about the long-term effects of nanoparticles. Basically, titanium dioxide and zinc oxide have a toxic effect on the human body. For this reason, caution should be exercised.

Chemical sunscreens: harmful hormones

Many people have an intuitive aversion to the word chemically. You automatically connect it to dangerous and negative. But it is worthwhile to take a more differentiated look at the matter. Many chemical processes happen in your body - some of them are positive and some of them are negative. So it is important to know which substances and processes you are talking about. Unfortunately, this is where things get more complicated with regard to sun creams.

What's in chemical sunscreens? While two substances are mainly used in physical sun creams, the list of organic filters used for chemical sun creams is significantly longer. Some of them are suspected to be carcinogenic. For most of them, we lack the long-term data to be able to say whether they are safe or not. However, it has been found that many of these substances can penetrate the body. The current most controversial ingredient in chemical sunscreens is oxybenzone. This substance is suspected of damaging coral reefs and influencing the human hormone balance (especially estrogens).

The FDA investigation

There are at least 16 minerals and chemicals in the United States that are used as active ingredients in sun protection products. For a large part of these active substances there is insufficient information about whether they are safe for use in the body and how they affect our blood system. According to the FDA, all ingredients that are detectable at 0.5 nanograms per milliliter or higher in the blood should be tested for it. The aim is to be able to make a statement as to whether these substances increase the likelihood of developing cancer, cause birth defects or have other effects.

In a pilot study, the FDA asked 24 test subjects to use avobenzone sunscreen products four times a day for four days. Then 30 blood samples were taken from each test subject over a period of seven days and the concentration of the active minerals and chemicals measured. After just one day, the concentration of the ingredients in the blood exceeded the recommendation of the FDA many times over.

The Federal Food and Veterinary Office

The Federal Food and Veterinary Office (FSVO) writes:

“According to the current state of knowledge, the benefits of mineral and organic UV filters outweigh any risks. The FSVO, the BAG, the Cancer League and the Swiss Society for Dermatology and Venerology recommend the consistent use of sunscreens on uncovered skin as a supplement to staying in the shade and wearing clothes. "

What now?

Great! So shouldn't you be using sunscreen at all? No! The FDA and the FSVO do not recommend doing without sun protection. That is clearly emphasized. But the FDA is campaigning to look carefully at what substances are used and how they affect the human body. The proposed FDA regulation should be finalized and come into effect in November. This could lead to some suppliers of sun protection products having to withdraw their creams, sprays and lotions from the market. The trade association has already requested that the entry into force of the regulation for eight ingredients be postponed because the tests have not progressed far enough.

Conscious use of sunscreen

Researchers agree that it still makes sense to protect yourself with sunscreen. The risk of skin cancer is real. Sunscreen is an effective protection against damage to the skin. But you should consider the following things:

• If you want to use a physical sun cream: Physical sun creams, which are advertised as transparent or invisible, often achieve this with nanoparticles.
• If you want to use a chemical sunscreen: Google the name of your sunscreen + ingredient. See if these are suspected of having negative effects on the body or the environment.
• Healthy people with no history of skin cancer do not always need to put on sunscreen. Often it is enough to look for shade or to be smart about the time you spend outside.
• According to the current state of research, caution is advised with the following ingredients: Tinosorb S and M, Mexoryl SX, Oxybenzone, Octinoxate, Avobenzone, titanium dioxide, zinc oxide, PABA and trolamine salicylate PABA.
• Read our article: When should you apply lotion?

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Further reading:

• Federal Food and Veterinary Office on sunscreen
• NPR article on sunscreen ingredients
• The best sunscreens
• Critical ingredients
• Overview of sunscreen ingredients

Sources:

• FDA study: Effect of Sunscreen Application Under Maximal Use Conditions on Plasma Concentration of Sunscreen Active Ingredients
• Further investigation by the FDA
• Investigation of whether zinc nanoparticles penetrate the skin
• Titanium dioxide and zinc oxide
• Chemical sunscreens
• Oxybenzone and estrogen
• Sunscreen and coral reefs