Photoprotection

In the era of the coronavirus pandemic, most of us have hidden in the safety of our homes. All week long we spent time with family without leaving our homes. It certainly gave us protection from COVID-19. At the same time, however, disease entities have emerged that until now did not affect such a wide social group or were even completely alien to us. We heard about mask acne, eczema and dry skin on the hands caused by wearing rubber gloves and using antibacterial gels with a high alcohol content, among other things. By staying at home, we also exposed ourselves to vitamin D deficiency.

As we know Vitamin D is synthesized by the skin when exposed to light. According to research, it only takes about 15 minutes a day of exposure to about 18% of the body (hands, forearms, calves) to deliver the necessary amount of the vitamin to the body. Therefore, outdoor movement is necessary for health.

However, as is always the case in life, there is also the other side of the coin. Exposing skin to the sun for too long can cause sunburn, irritation, allergies and even cancer. Therefore, it is important to protect the skin from the sun’s rays. And most importantly, the use of sunscreens, even the highest ones, does not block the mechanisms of vitamin D synthesis in the skin!

Solar radiation

We can divide ultraviolet radiation into three ranges of the wave spectrum:

UV-C (100-280nm)

It is a very short wave, but with the highest energy. It does not reach the Earth’s surface because it is absorbed by the ozone layer of the atmosphere. If not for it, UV-C radiation would kill living organisms. Light used, among other things, in germicidal lamps to decontaminate equipment and rooms.

UV-B (280-320nm)

Much of the radiation is trapped by the Earth’s atmosphere. It accounts for only between 4-5% of the UV radiation reaching the Earth. UVB is responsible for the formation of delayed tan. Melanin (a pigment contained in the skin) is not produced until 48-72 hours later. Thus, the tan develops later, but, importantly, stays for longer. It is mostly absorbed by the stratum corneum, with only a small amount penetrating into the dermis. UV-B radiation has strong erythematogenic properties, can cause sunburn of the epidermis and dangerous damage to skin cells. But most significantly, it is responsible for the production of vitamin D3. On the other hand, prolonged exposure can cause skin malignancies.

UV-A (320-400nm)

The intensity of the wave is the same throughout the day, regardless of weather and season. UV-A rays have the ability to penetrate clouds, glass and human epidermis. It accounts for as much as 95% of UV radiation reaching the Earth. It is responsible for the formation of an instant tan. It is visible after a short period of tanning, but lasts only a few hours. Under the influence of UV-A radiation, sunburns are not produced, which is apparently safe. However, nothing could be further from the truth. The wave penetrates deeply and reaches the dermis. Under its influence, changes in cellular DNA that are invisible to the eye are produced. The effects of radiation are cumulative and cause photoaging of the skin.

Blue Light

Blue light (400-500nm), or blue light, is the shortest wavelength in the range of visible radiation. Blue light is emitted by the screens of phones, smartphones, tablets and televisions. That is, all those devices that are related to the LED source. And just as vitamin D deficiencies are the result of a deficit in sun exposure, blue light is associated with a measure of light exposure to the skin. Every day we are exposed to hours of blue light because electronic devices surround us from all sides. They are replacing us with books, newspapers and even direct contact with another human being. Blue light generates a similar amount of free radicals as UV-A and UV-B radiation combined. It penetrates to deeper layers of the skin than UV radiation. Causes shortening of the lifespan and proliferation of fibroblasts. It can also cause DNA damage and premature skin aging. Blue light penetrating deep into the skin has destructive properties noticeable in all layers. It induces oxidative stress, weakens the epidermal barrier, causes hyperpigmentation and leads to premature skin aging.

Photoaging of the skin

Overexposure to the sun’s rays can cause photoaging of the skin. The effects are noticeable in every layer of our skin. In the epidermis, there is a noticeable reduction in the thickness of the stratum spinosum and granular layer, while the stratum corneum is visibly thickened. Melanocytes cluster causing the formation of pigment spots and discoloration. The skin also becomes dry as a result of the disruption of NMF production. The skin is less resistant and more susceptible to irritation and allergies.

In the dermis, the activity of fibroblasts decreases, thereby reducing the synthesis of collagen, elastin and hyaluronic acid. Water binding capacity is also decreasing. The network of blood vessels is also changing. Some of them atrophy, causing deterioration of cell nutrition and oxygenation. Teleangiectasias also appear.

In the subcutaneous layer, the density of adipose tissue gets colder. In addition, numerous wrinkles and furrows appear.

Sun protection

On the cosmetic market we have a numerous group of cosmetic raw materials that perform the function of sun protection. The list changes all the time and is updated by the European Parliament in terms of function, range of allowed concentrations and toxicity.

Proper selection of chemical ingredients including UV filters is a challenge for manufacturers. Filters, first of all, must do their job, which is to protect the skin from harmful radiation. They should also be physically and chemically stable. The chemicals should remain on the skin and not penetrate into the dermis, but at the same time be resistant to contact with water and sweat, as well as to mechanical abrasion.

Types of sunscreens

Mineral filters

• zinc oxide (inci: zinc oxide),
• titanium oxide (inci: titanum dioxide)

Physical filters are chemical compounds of mineral origin. Designed to reflect and scatter solar radiation. Mineral filters are primarily used in vege and organic products, for children and people with sensitive skin. They remain on the surface of the skin and do not penetrate into the deeper layers. As a result, they do not cause sensitization and irritation. The downside is that it leaves a white film on the skin and the particles are unevenly distributed on the skin surface, necessitating the use of additional ingredients to help spread the film evenly on the skin giving continuous protection. The important thing is that mineral films provide UVB protection and relatively good UVA protection.

Chemical filters

This is a very large group of chemical compounds – organic compounds that absorb solar radiation and convert it into thermal energy. The small particle causes penetration into the deeper layers of the epidermis, and thus can cause irritation and allergy. The undoubted advantage, on the other hand, is that the texture of the cosmetic is light and does not leave a white residue on the skin. Chemical filters are further divided in terms of radiation absorption into:

• Narrow-spectrum filters – absorb UV-B radiation and part of the UV-A spectrum
• Broad-spectrum filters – absorb UV-A and UV-B radiation

UV-A filters include, but are not limited to:benzoylmethane derivatives (inci: Butyl methoxydobenzoymethane)

UV-B filters are, for example: cinnamic acid derivatives (inci: ethylhexyl methoxycinnamate) or Octocrylene (inci: Octocrylene), which further increases the photostability of the cosmetic.

Wide-band filters including the blue light spectrum – for example: triazine and phenylbenzotriazole derivatives (inci: methylene bis-benzotriazolyl tetramethylbutylphenol), which is a new type of filter, since it behaves partly like a chemical filter, i.e. absorbs radiation, while partially reflecting light, which is characteristic of mineral filters. In addition, it does not penetrate deep into the skin.

Natural filters

The concept of natural filters is also known in cosmetics. Oils (soy SPF 10, avocado SPF 4-15), butters (shea SPF 10) and plant extracts (green tea, aloe vera) contain a natural form of chemicals that are the equivalent of synthetic filters. However, the protection they provide is too low and the spectrum is too narrow for them to act alone. They are often included in the formulation as an additional enhancement of the radioprotective effect and as an antioxidant.

Proper sunscreen design should include broad protection against both radiation, but also help protect against free radicals.

Sun protection factors

The European Cosmetics Industry Association has set guidelines for the classification of sunscreen products, or SPF (Sun protection Factor). The value expresses how much a cosmetic product protects the skin from UV-B radiation. This is the standard by which consumers can determine whether a cosmetic product meets their expectations. In addition, the European Parliament has imposed the exact degree of protection that must be found on the packaging of cosmetics.

Full sun protection

Is there a concept of complete sun protection? Certainly not! It is necessary to remember that no chemical substances fully protect us from the negative effects of ultraviolet and also visible radiation. It is worth remembering to buy sunscreens that protect the skin from radiation across the UV-B and UV-A spectrum and provide high photoprotection. Also of added value is the aforementioned blue light. This is a relatively new concept that has emerged with the rise in popularity of electronic devices. However, its effects will undoubtedly quickly appear on the skin.

We should use filters every day all year round and reapply multiple times throughout the day to maintain protection whether we spend the day at the office, walking in the park, planning a vacation trip to exotic countries or skiing in the winter. In addition, it is not recommended to stay out in the sun from 12-15 pm, especially during the summer. During this time, radiation has the highest intensity.

There is a large group of filters available on the cosmetic market and so we are able to choose the right product for our needs. The market offers us products with different strengths of sun protection (SPF), a variety of formulations (emulsion, oil, mist, stick) and even packaging (atomizer bottle, airless). As a result, we are able to select the right product for our needs. Also in terms of fragrance, formulation density or absorption speed. In addition, it is worth noting the light consistency of the filter so that after absorption you can easily apply your daily makeup.

Remember to apply sunscreen to the skin several times a day. In particular, after a bath or in the case of mechanical friction.

Video webinar

We regularly remind you how important photoprotection is. Today we will explain exactly what photoprotection is, what radiation is and what effect it has on our skin. Our specialist Malgorzata Pawlowska will tell you about it.

He will talk in a clear and accessible way about how radiation works, the differences between UV-A and UV-B. Pay attention to the slides – a lot can be illuminated by a pictorial representation of the topic. There will be a few words about Blue Light – it is often mentioned, but can you really explain what it is and why it is more harmful than UV? We will touch on the topic of filters – what active ingredients are worth having in a sunscreen, and what is the difference between chemical and mineral filters.