By learning more about sunscreens, you can find out that they have their light and dark sides. It is certain that they protect our skin against ultraviolet radiation – for a limited time after application. Some UV filters are absorbed into the skin and leave no trace, and do not form a white layer. After taking a water bath they like to weigh on the skin or wash off completely and then we leave our skin completely defenseless. After hours spent in the sun, erythema often appears on the skin. Some of them disappear after a few hours, and some persist giving a burning sensation, pain, itching. To know how to protect yourself and remember that you must do it. You should get information on what sunscreens really give us. What processes in our skin they prevent, whether there is a difference. In the use of a filter with an SPF of 6 and 50 and which UV filters are best avoided. Taking into account their composition and our phototype.
Good and bad sides of UV radiation.
Oxidative stress, photoaging, skin cancers are generally the basic negative effects of UV. However, to discover them from the inside out, you can’t fail to mention the distribution of radiation. UVA and UVB are types of radiation that otherwise penetrate deep into the skin and give a different skin reaction. UVA penetrates through the glass and clouds, reaches the proper layer of skin. Due to its length, it causes much more damage than UVB, which they are after prolonged or chronic exposure; formation of reactive oxygen species, i.e. free radicals, leading to oxidative stress. Thus, destroying the cell structure of the entire body including valuable collagen and elastin, which accelerates the skin aging process. It often damages capillaries and also leads to mutations in the genetic material.
In addition, erythema that develops, which appears immediately after or even during exposure. It disappears after a few hours from the end of the sun bath. To appear again after some time as delayed erythema. It causes the formation of freckles, hypo- or hyperpigmentation, and sometimes can be synonymous with phototoxic or photoallergic reactions. The good news is that it is UVA that provides us with a darkening of the skin color, which is tan. UVB does not penetrate through windows and clouds, it is indirectly inhibited by atmospheric factors, reaches maximum the basal layer of the epidermis, including keratinocytes, Langerhans cells and melanocytes. It contributes to the development of cells, is much more toxic and mutagenic despite lower penetration, with longer exposure it lowers immunity and also reduces the amount of hyaluronic acid in the skin, leading to dryness.
Erythema appears about 4 hours after exposure. Its peak falls from 8 to 24 hours, to disappear in a day or stay for several days. It is closely related to the expansion of the capillaries, and through the damage to keratinocytes, an inflammatory reaction occurs. The broadly understood biological processes following exposure to the sun are not only and exclusively those mentioned above. Due to the latitude in which we live, we are not able to live in the sun all year round. That is why each of us wants to draw handfuls so much whenever the opportunity arises.
For the most part it is due to the well-being in which the rays of the sun put us. Taking sunbaths, we feel relaxed, which often makes us fall asleep easily.
Stimulating melatonin secretion and increasing oxygenation of all body tissues improves mental and physical performance. It makes us function much better in everyday life.
UVB radiation initiates and directly affects the vitamin D transformation cycle. To finally lead to the formation of the active form of vitamin D – calcitriol in the kidneys. It is she protects us against depression, mood disorders, ensures proper development and functioning of the body, regulates calcium and phosphate metabolism, cares for bone mineralization, protects children against rickets and the elderly against osteoporosis. Studies confirm that an appropriate dose of UV radiation increases our tolerance to skin grafts, and also reduces or affects the complete re-emission of dermatological diseases such as atopic dermatitis, seborrhea or psoriasis.
Who is the filter for?
Breed is our natural sun protection. In our latitude, the most common breeds are Celtic and Caucasian, the second of which is predominant. Celtic are people with blond or red hair and very light skin. These people almost always get erythema when sunbathing. Therefore, it is recommended to use UV filters with the highest degree of protection, and preferably to avoid the sun. Lucky people can be called people who during tanning immediately get a gold brown tan. They belong to the Caucasian with phototype II and even III, and their melanosomes are highly concentrated and filled with melanin. Phototype V and VI, in turn, is a dark and negroid Caucasian race in which erythema never occurs. Due to the fact that our natural protection is not enough to combat UV radiation, we must use UV filters. They are designed to counteract the negative effects of radiation mentioned above. Sun protection products must meet the requirements as they enter the market; water resistance, photostability, low penetration of molecules into the skin, non-toxicity, no tendency to cause photosensitizing, photoallergic reactions, irritations, but also carcinogenicity.
To find out which UV filters are the most convenient for us in terms of our phototype and race. It should be observed after what time from the first minutes of exposure erythema occurs on the skin. Minimum erythema dose. If the result of our observations is 5 minutes, and we want to apply a 20 filter. It means that we could spend a total of 100 minutes in the sun (we multiply the time of the minimum erythema dose by the height of the filter and we get the result). However, given that each skin reacts differently, we can’t expect the same reactions for everyone. Therefore, to optimize and create maximum safety for the skin and health of each of us. It is recommended to divide the theoretical sun exposure time by 4.
We divide UV filters into physical and chemical. The first act by reflecting or scattering sunlight, while the latter absorb radiation. Physical otherwise inorganic, they have the ability to protect our skin against both UVA and UVB radiation.
Chemical or organic filters are divided into subtypes that have different ranges of UV absorption. Which means that not all of them protect us against UVA and UVB rays.
Inorganic so-called mineral due to the large size of the particles. Don’t penetrate deep into the epidermis (maximally to the stratum corner). Are divided into colored pigments with larger particle sizes and micronized pigments with smaller particle sizes. Color pigments reflect visible light, which is why they leave a white layer. On the skin after application, which we try to avoid. However, thanks to this property they are among the safest. The effect of micronized particles avoids the unsightly appearance of whitening, while maintaining the filter’s power. The most popular ingredients in this group of filters are zinc oxide, titanium oxide, titanium dioxide and iron oxide. Due to the fact that titanium dioxide in the micronized form often leads to the destabilization of the product. They are covered in the production process with alumina or silicon oxide – i.e. silicones.
The action of organic filters is based on the isomerization of the carboxyl group and the penetration of these components deep into the epidermis. Only wide-spectrum filters of this type protect the skin against UVA and UVB rays. The most modern chemical filters are insoluble in water. Which allows for a long period of operation, they also have a high molecular weight. Which prevents them from penetrating the epidermis excessively.
UVB chemical UV filters:
– Paraaminobenzoic acid and its derivatives (PABA) – not recommended for use especially for people with dermatological problems due to frequent phytotoxicity and photo allergic reactions,
– Derivatives of p-methoxycinnamic acid (INCI: Octyl Methoxycinnamate, Isoamyl p-methoxycinnamate) – may cause slight irritation and allergy reactions, more often it replaces PABA derivatives,
-Octocrylene (INCI: Octocrylene, 2-cyano-3,3-diphenylacrylic acid 2-ethylhexyl ester) – one of the safer preparations, loses its properties on contact with water or sweating
UVA chemical filters:
-Benzylidenkamphor derivatives, Mexoryl SX® (INCI: Terephthalylidene Dicamphor Sulfonic Acid),
-Butylmethoxydibenzoylmethane, Parsol 1789® or Avobenzone (INCI: Butyl Methoxydibenzoylomethane) – may cause photo allergic reactions.
UVA and UVB chemical UV filters – wide range:
-Benzophenones (INCI: Benzophenone-3, Benzophenone-4, Benzophenone-5) – must be checked in the composition of Benzophenone,
-3 due to the fact that it passes into breast milk and urine, can be allergic,
-Tinosorb®M (INCI: methylene bis-benzotriazolyl-tetramethyl-butylphenol),
-Tinosorb®S (INCI: Bis-ethylhexyloxyphenol Methoxyphenyltriazine)
Closer to nature
Due to the ubiquitous chemistry in cosmetics and the desire to be more “eco”. Manufacturing companies have met customer expectations and created UV filters containing natural extracts derived from
from plants. These extracts have the ability to absorb ultraviolet radiation to a large extent. Despite the health properties they possess in this sunscreen, unfortunately, they cannot form the basis of sunscreen products. They have a positive effect on the skin condition, thereby reducing the negative effects of photoaging and fight free radicals. Photoprotective extracts include: inflorescence, catkin, chamomile, rhizome
and root of Baikal thyroid, green tea leaves, bee putty, aloe extract, shea butter, cocoa butter, argan oil, macadamia, sesame, avocado, long pepper, saffron.
UV filters are undeniably inseparable and basic photoprotective element. They protect our skin against any burns, photodermatoses. It should be remembered that their application must take place about 15 minutes before exposure. To allow the ingredients to be properly absorbed. UV filters should be used not only on the beach, but also when we are exposed to all kinds of exposure.
Application renewal is necessary and must take place every 2-3 hours on average.After the water baths, the filter should be applied again, because even the UV filter’s waterproof properties do not provide us with effective protection against the sun. It is necessary to choose the right SPF indicator for our phototype and individual response to radiation. It is worth leaning over the type of UV filter; chemical or physical and choose it according to our requirements and needs. Plant extracts contained in photoprotective products fight free radicals and condition the skin.
