Sun Filters – the goodies and baddies

Edited by :

Elisabetta Damiani (“Liz”) – Senior Scientist, Department of Life and Environmental Sciences – Marche Polytechnic University, Ancona, Italy.



The function of sun filters is obviously to prevent your skin from burning in the sun and being aged and damaged by harmful UVA (wavelengths between 320-400 nm) and UVB (wavelengths between 290-320 nm) rays.

There are many sun filters available on the market for sunscreen manufacturers to use in their consumer products. These are either physical or chemical and all these sun filters are chemical compounds.

The physical filters are usually mineral compounds, such as Titanium Dioxide and Zinc Oxide.

The chemical filters are organic compounds, and many different types exist according to their chemical structure. Some can absorb UVA rays, some can absorb UVB rays and some can absorb both.

Frequently, both physical and chemical filters are used in sunscreens to obtain a better and more protective product, because different sun filters are effective against different UV rays.

However, the same levels of protection can be obtained with mineral compounds (physical filters) or by using only organic compounds (chemical filters).  Also, by using different sun filters in a sunscreen, high levels of sun protection (SPF) can be obtained.

How they work

Using mineral compounds/physical filters, the UV rays are literally not able to  penetrate the skin because they are mainly reflected and scattered by the filter. These filters are the ones used in the sunscreens that often look white on the skin and are also often referred to as sun blocks.

To avoid them looking white and to ensure that they still block out the UV rays, the particles are made smaller so that you and I cannot see them. Trouble is, these nanoparticles are so small they may be able to penetrate the skin and be absorbed into your body.

According to some scientists some of these, notably Titanium Dioxide and Zinc Oxide, can also do longer term harm to you.

In the case of organic compounds/chemical filters, the UV rays are absorbed, “soaked up”, by the sun filter, and in so doing, the rays are converted into less harmful and safer ones, such as infrared rays.

Some of the best chemical sun filters according to recent research are:


A) MBBT, Methylene bis-benzotriazolyl tetramethylbutylphenol, Bisoctrizole, Tinosorb M

B) DHHB, Diethylamino hydroxybenzoyl hexyl benzoate, Uvinul A Plus

C) EHT, Ethylhexyl triazone, Uvinul T 150

D)  BEMT, Bis-ethylhexyloxyphenol methoxyphenyl triazine, Bemotrizinol, Tinosorb S

Photodegradation, which consists in an irreversible change in the sun filter after it has absorbed/reflected/scattered the UV rays, making it less efficient, is another issue concerning some sun filters.  

The above synthetic compounds are those that have had among the best results according to the following studies:



Everybody wants a beautiful skin that stays young and healthy for a very long time. However, aging, sun exposure, an unbalanced diet, and stress are just a few factors that prevent our skin from looking great. This is where antioxidants come to the rescue, because, if wisely introduced into the daily diet and skincare routine, they can work miracles.

What are antioxidants?

Oxidation is a natural chemical process that occurs at the cell level in our body. If you have seen a peeled apple turn brown, then you have witnessed an oxidation process, and it is not pretty. Antioxidants are chemicals that have the property of preventing the oxidation of cells. They can be found in our body, as well as in fruits and vegetables, in the form of enzymes, vitamins and minerals.

The most popular antioxidants are vitamins A, C and E, beta-carotene, selenium and magnesium. They are joined by coenzyme Q10, lipoic acid, flavonoids, lutein, lycopene, and many others.


How do they work?

Our body produces daily the dreaded free radicals that we always hear about. The process occurs as a side effect of breaking down food and turning it into energy; some free radicals form at the skin level after sun exposure. These free radicals are lacking in electrons, which they end up stealing from molecules present in our body. Antioxidants act as electron donors to the free radicals, thus preventing them from damaging our body tissue.

While protecting us against the attack of free radicals, antioxidants end up being oxidized; therefore, it is important to keep replenishing our body’s supply of antioxidants. We can take them out of foods rich in antioxidants such as berries, green tea or whole grains, skincare products that contain them, and manufactured dietary supplements.


Antioxidants and skincare

In skincare, antioxidants can help slow down the aging process and protect our skin from the damaging effects of the sun. Antioxidants protect the cells from damage and encourage tissue growth, which is very helpful to the skin’s constant regenerating process.


Some of the best-known antioxidants for their benefic effects on our skin are:

  • Vitamin A – also known as retinol, is key for cell growth;
  • Vitamin C – ascorbic acid, is an antioxidant that helps tissues grow;
  • Vitamin E – helps the body regulate retinol levels, which is essential for healthy skin;
  • Coenzyme Q10 – also known as CoQ10, helps protect cells from damage;
  • Selenium – is a mineral that may help protect the skin against sun damage and wrinkles.


Sources to open in new pages:

Discovery Fit & Health:

Harvard School of Public Health:

US National Center for Complementary and Alternative Medicine: