(1) A Sun Protection Factor (SPF) measures the level of UVB protection a sunscreen or a piece of sun protective clothing gives you. It indicates the length of time that your skin is protected from sunburn. For example, when you use a sunscreen with an SPF of 20, it means that this sunscreen would provide 20 times the protection of no sunscreen.
As you can figure out, no sunscreen will give you 100% protection after a single application. SPF should be specific for each phototype, i.e. skin color, and the season of the year (summer or winter). Fair skins need more protection, so they should get a sunscreen with a higher SPF, while dark skins can use lower SPFs. Also, in winter we do not need as much protection as in the summer.
(2) Sunscreens should be: stable when exposed to light, neutral, non-greasy, non-irritating, non-disinfectant, non-dry, odorless, effective, 50% water-resistant, non-interactive with other chemicals, long-lasting, and have an indefinite shelf life, which means that they are extremely stable and can tolerate high heat, UV light and moisture without disintegration, they are sweat- and seawater resistant.
Sunscreens should be chosen according to where they will be applied and the person’s skin quality.
The best face sunscreens for oily skin are the ones with really thin texture, while for dry skin look for one with a creamy or balm-type texture.
Lotions, gels, foam, alcohol-based or oil-based creams, depending on the quality of the skin, are best applied to the body.
For the sensitive skin on nose, lips, and around eyes, use special sunscreen sticks.
Expert advice is of utmost importance for choosing the right sunscreen.
(3) For best protection, experts recommend we apply the proper amount of sunscreen on our skin (2mg/cm2 or 22ml/cm), that is half a teaspoon per one square centimeter of skin, an amount quite large. Studies have shown that most people under-apply sunscreens, using about ¼ of the amount required, which we must take into account, as this way we are not fully protected. The right way to use sunscreen is to apply on dry skin, at least 30 minutes before going out in the sun and reapply every two to three hours. So, let’s be more careful when using the sunscreen we have bought and be generous on the quantity we apply, otherwise we forfeit the protection of our very health.
(4) Sunscreens are chemical agents that help prevent the sun’s ultraviolet (UV) radiation from reaching the skin and prevent or minimize the harmful effects of this radiation on the skin. Depending on their chemical structure, they are chemical or organic and physical or inorganic. Physical sunscreens contain zinc oxide and titanium dioxide and form a thick, white layer on the skin. They mainly protect from UVB radiation and are ideal for children and patients with photodermatosis. Chemical sunscreens are colorless and often have a nice scent. They protect from both UVA and UVB radiation. All sunscreens (or photo-protectors) contain ingredients (chemical molecules) that protect the skin by absorbing, reflecting or scattering solar radiation: UVB (the shortwave ultraviolet rays, the chief culprit behind sunburn) and UVA (the long-wave ultraviolet rays that cause wrinkling and cancer). Sunscreens protect the skin from direct side effects, such as sunburn, or effects you do not feel right away, such as photo aging, photo carcinogenesis etc.
(5) Provided they meet the above requirements, the protection sunscreens offer is essential, as the skin conditions caused by radiation vary significantly, and some of them may end up being very severe. They may start from erythema (redness) and grow to solar elastosis (which causes sagging skin and wrinkles), skin cancer, pharmaceutical photosensitivity, deterioration of certain dermatoses. As mentioned above, the SPF protects from 2 to 30 or 50 times more, but not 100 times more. The time you can spend in the sun before you start to burn your skin depends on lots of factors, such as the sunscreen type, its properties, the time of day, the season, the phototype. So, sunscreens protect according to their SPF and only for a certain amount of time; from ten minutes to about six hours, depending on all the factors mentioned above.
However, future protection strategies focus especially on the use of sun protective clothing. This is a special category of wearable products, made with materials designed to block out damaging sunlight, providing effective and optimum protection to the consumer from the harmful effects of UVA and UVB radiation.
In 1998, a team of scientists proved that the protection offered by a simple light-colored T-shirt corresponds to an SPF of 10. On the basis of laboratory testing of the ultraviolet protection factor (UPF) provided by fabrics, distinguished scientists (Ravishankar and Diffey) came to the conclusion that the protection offered by attire depends on its fiber composition, color and moisture content. Protection is measured according to UPF (Ultraviolet Protective Factor). UPF represents the ratio of erythema (sunburn)-causing UV measured without and with the protection of the fabric. According to it, protection is good (UPF 15-24), very good (UPF 25-39) and excellent (UPF> 40). Sun protective clothing control criteria have been defined by the Skin Cancer Foundation. The active ingredient infused into fabric fibers to improve UV filtering is called TINOSORB FD. TINOSORB FD has proven to be an excellent sun filter for both UVA and UVB radiation.
Sun protective clothing can be a safe and effective solution for UV protection if combined with a good sunscreen, sunglasses, a wide-brimmed hat and a beach umbrella!
(6) Melasma (skin discoloration) or spots are light or dark brown patches that appear on the face, in areas that get lots of sun. It is particularly common in women, especially pregnant women and those who are taking oral contraceptives or other medications. These spots have a larger number of melanosomes containing melanin. Melanin absorbs radiation, causing the skin to appear darker at places, as the absorption of radiation increases the size of the melanocytes. So, skin with discoloration needs more sun protection and special care at home, all year long, so that melanocytes not deteriorate during summer. People with no discolorations should also be very careful, as these brown patches are primarily caused by exposure to sun.