Things to know about UV filters


Sun and self-protection

If you spend time in the sun, your complexion changes - depending on your skin type. This is due to melanin, the skin's tanning pigment. Melanin is nothing more than the body's own light protection filter, because it converts the sun's UV radiation into heat. The sun's own light protection filter is supported by UV filters in sun protection products.

The fact that this self-protection mechanism of the skin exists at all has, of course, no aesthetic reasons. UV radiation damages the skin when overdosed, makes it turn red (up to sunburn) and promotes its aging or even skin cancer. How fast this happens depends on the individual self-protection time. This is the amount of time you can expose your untanned skin to the sun without getting sunburned. Find out more about what type of sunscreen you are here.

  • The self-protection time should be used with caution, because depending on the time of day, season or location, the actual self-protection may be lower.
  • So if you're not exactly the southern type, you should be careful. The limits of the body's own protection are quickly reached, especially in exposed areas such as the face, neck, ears and hands.

Sunscreen prolongs self-protection

Fortunately, there are sunscreen products that protect against UV radiation to the greatest extent possible - as long as you use them correctly. You should never rely on sunscreen alone, because:

  • The SPF (sun protection factor) is a value determined in the laboratory under laboratory conditions. UV light always hits the skin evenly in the laboratory, which is never the case in reality.
  • Clouds, the ozone layer, the position of the sun (and the resulting different levels of UVB radiation), a stay in snow or water are only comparable to a certain extent with the time span calculated under laboratory conditions.
  • The SPF number on your sunscreen product can only ever be a guideline!
  • After applying sunscreen, the calculated protection time is also a guideline - it's best to take other measures to protect yourself from sunburn much earlier, about a quarter of the calculated time.

How much sunscreen do you need?

To achieve the advertised sun protection factor, you need to apply a lot of sunscreen, a lot. 2 milligrams of sunscreen per square centimeter of skin. This corresponds to about ⅔ teaspoon for the face or a shot glass full for the entire body. However, these guidelines are only rules of thumb.

  • If you use less sunscreen, the light protection is also lower, much like the opacity of wall paint decreases if you apply too little of it.
  • Taller people naturally need more sunscreen than shorter people.
  • An average adult needs 36 milliliters to provide the entire body with sufficient sun protection. A small measuring aid: This corresponds to a barely filled shot glass.
  • If this amount seems too much when applying each lot, you can also apply the sunscreen in two layers.

Sunscreen, sun oil or spray - what amount do I need?

Another sticking point of standardized measurement methods in the laboratory is that the specific material properties of the formulations or filters tested are not taken into account. The quantity mentioned at the beginning behaves quite differently on the skin in the case of an oil than in the case of a cream. Unfortunately, there is no generally applicable rule for this.

  • Stick to the manufacturer's recommendations - paying attention to the term "recommendation".
  • People have different sized body surfaces and therefore need more or less of the product.
  • Also trust your common sense and if in doubt, apply too much or reapply regularly.

How inorganic light protection filters work

Whether cream, spray or oil - all products have in common that they should protect against UV radiation. But which ingredients actually work in such a cream?

These are the light protection filters. They are roughly divided into two categories: In organic and non-organic or inorganic light protection filters. In addition, there are many products that even combine both filters. This is how inorganic filters work:

  • Inorganic light protection filters consist of titanium dioxide or zinc oxide, minerals that have been ground into powder.
  • The minerals found in the sunscreen product work on the surface of the skin: they form a film that absorbs UV light and converts it into heat.
  • In addition, the inorganic filters titanium dioxide or zinc oxide act like small mirrors, reflecting a small amount of UV radiation and dispersing it.
  • They are usually well tolerated, so that skin problems or even allergies rarely arise. That is why they are mainly used in lotions for children or babies.
  • Another advantage is that the protection is immediate. A lead time of about 20 minutes, as often recommended, is not necessary with mineral light protection filters.
  • One drawback: the texture of inorganic filters is usually rather heavy and on darker skin the white film can be annoying.

Small particles, big concern: nanoparticles in sunscreens

For a long time, one disadvantage of mineral filters was their "wearing comfort. To provide sufficiently high protection, a corresponding amount of pigment had to be added to the cream or milk, and this resulted in a white layer on the skin.

The industry has been able to reduce the particle size further and further, which not only significantly improves said comfort, but also the effectiveness of these filters. We have long since arrived at the nanoscale. This means that the particles are 100 nanometers or smaller.

To understand how big or small a nanometer is, imagine a soccer ball next to the planet Earth. This corresponds approximately to the size ratio of a nanoparticle to a soccer ball!

With the use of nano-filters, however, the discussion began that nanoparticles could penetrate the organism through the skin and have unpredictable effects.

Numerous studies clearly give the all-clear: A harmful effect on health has been ruled out. In extensive tests with sun creams containing titanium dioxide and zinc oxide, no residues could be detected in deeper layers of the skin or the blood - provided the skin is unharmed.

  • The particles remain on the skin or in the uppermost skin layer - provided, and this is an important aspect - the skin is intact, i.e. neither injured nor inflamed.
  • That is why public bodies such as the Cosmetics Commission of the German Federal Institute for Risk Assessment and the Australian health authority TGA have approved the use of both substances in sunscreens.
  • We find one restriction important to mention: Make sure that spray products are free of nanoparticles. In sprays, nanoparticles can be inhaled via the spray mist and thus enter the organism.
  • By the way: You can always tell whether a cosmetic product contains nanoparticles by the addition "(nano)" in the list of ingredients (INCI).

How organic light protection filters work

  • Organic light protection filters include all filters that do not exclusively contain titanium dioxide or zinc oxide.
  • Organic light protection filters also form a film on the skin that absorbs UV light and converts it into heat.
  • New and modern filters such as Tinosorb S and M additionally reflect a small amount of UV radiation and disperse it.
  • Organic filters are pleasant to wear in texture, even with high sun protection factors.
  • Both organic and inorganic filters do not need to come into contact with the skin to be effective. Applied to a surface made of stone, they would absorb UV light just as effectively as on the skin.

Organic, inorganic or both?

Both active principles have their advantages and disadvantages, so a blanket pro and con is too inaccurate. Organic filters in particular are often criticized, although the latest generation of these filters is very good: they are considered to be consistently well tolerated and photostable (i.e. they do not change under UV radiation).

Among organic filters there are good and not so good ones

The less good filters are suspected of influencing the body's hormonal balance, triggering allergies or changing when exposed to sunlight and forming free radicals, for example.

It is also complicated by the fact that there is no "one" light protection filter that offers ideal wearing comfort and the best possible UV protection at the same time.

Modern sun protection products therefore combine different filter substances

The combination of different filters enables the broadest possible protection against the UVA and UVB spectrum. In the meantime, there are even light protection filters that combine both of the above protection principles: Tiny UV-reflecting pigments are additionally "docked" with organic compounds, which in turn convert parts of the UV radiation into heat.

Good filters - bad filters

You have already experienced that not every UV filter is good - some trigger allergies or interfere with hormone balance. Of course, your skin condition is also important - on healthy and uninjured skin it is much less likely that UV filters enter the body. If you have now discovered a less good filter in your product and no possibility to switch to a product with good filters, rather use your existing product than none at all.

Here is a selection of good filters:

Tinosorb S, Tinosorb M, Tinosorb A2B, Uvinul A Plus, Octisalate,
iscotrizinol, Mexoryl XL.

By the way - these state-of-the-art UV filters are used by HighDroxy:

  • In DAY LIGHT 30: Tinosorb S, UVASORB and Uvinul A Plus
  • In D-FENCE 50: Tinosorb S, UVASORB HEB and Uvinul A Plus

With a sunscreen product you should pay attention to the following things

  • Choose a product that suits your skin type and any skin problems you may have.
  • Your sunscreen product should have a sun protection factor of at least 15, but preferably higher.
  • The product should protect against UVA and UVB radiation.
  • To achieve the promised sun protection, the product should form in an even layer between the sun and your skin.
  • Allow the product - especially if you use follow-up products or make-up - to absorb for about 10 minutes. This makes further handling easier.
  • Depending on the conditions, renew the protection every 2 hours.

UVA and UVB: Good sun protection is a balancing act

Probably the most popular guide to choosing sun protection is the sun protection factor, or SPF. The sun protection factor - or SPF for short - increases with the number of UVB filters contained in the cream: The more UVB filters, the higher the SPF.

  • Which sun protection factor is suitable is completely individual and must be determined via self-protection. This depends primarily on the skin type, but also on whether the skin is already accustomed to the sun. At the end of a summer vacation, the skin already has somewhat more inherent protection than at the beginning.

  • The second criterion is to assess how intense the sun is in the place where you want to be. When hiking in the Alps in high summer, you need a higher sun protection factor than on a sunny autumn day in London.

In addition to the UVB spectrum, good sunscreen also covers UVA radiation. If it does this in sufficient quantity (i.e. always at least 1/3 of the SPF), it is allowed to carry the UVA seal in the EU:

sunscreen uva seal

Last but not least: Your checklist for buying sunscreen

  • Knowyour personal self-protection time, which corresponds to your light protection type and choose your SPF accordingly.
  • Look for the circular UVA symbol
  • When evaluating the product, think about the required application quantity, especially in the case of light protection products for the face: Is the texture of the product sufficient? Is it possible to apply the product twice?
  • Concerns about physical filters in nano size are unfounded according to current research. If you still want to avoid mineral nano particles, you can easily recognize them by the (mandatory) addition "(NANO)" in the INCI list.

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