Skin protection from sun damage is a daily must-do to prevent it from photoaging and multiple disturbing and dangerous skin conditions, including cancer. In this post, you will get a better understanding of the side effects of excessive sun exposure, the difference between SPF cream types, and useful advice on how to use them correctly.
Sunlight consists of many different types of rays. Ultraviolet (UV) rays are the most damaging to our skin: UVA rays are associated with skin aging and UVB rays – with skin burning. Both types are shown to induce skin cancer. There are approximately 500 times more UVA rays present in sunlight than UVB.
How do UV rays damage the skin?
UVA rays penetrate deep into the dermis damaging the collagen fibers. The skin experiences dehydration and loses its elasticity, resulting in sagging and wrinkle formation. This process is called photoaging. Skin stretching can also lead to pore opening and enlarging.
Studies show that UVB can activate sebaceous glands and cause excess sebum production, which may undergo peroxidation by UV light and damage the barrier functions of the skin.
Excessive sun exposure causes the skin to increase melanin production to protect itself. Sometimes the extra melanin is uneven and leads to the irregular skin coloring called hyperpigmentation. It’s especially risky to stay in direct sunlight during post-injury skin conditions, after cosmetic procedures like chemical peelings, and photo or laser treatments.
What are the types of SPF creams?
Some SPF creams leave a white cast. Some of them are very thick, and some are not. It depends on what kind of sun filter the product has – physical or chemical.
Creams based on physical filters (sunscreens) reflect UVA and UVB rays away from your skin. They act like a shield, not penetrating the skin. And they can leave a white cast.
There are two physical filters:
Zinc Oxide – it doesn’t absorb into the skin, reflects UVA and UVB rays, and fights inflammation;
Titanium Dioxide – protects from UVB rays and partly from UVA; not allergic but can be comedogenic.
SPF creams with physical filters are shown to be safe and are a good fit for people with sensitive skin, children, and pregnant women.
Creams based on chemical filters (sunblocks) absorb the sun’s rays. They are soaked up by the skin and don’t leave a white cast. Such creams should be applied 20 minutes before you go outside.
There’s a large amount of chemical filters, and not all are effective against UVA rays. That’s why they are often combined with each other or, better, with physical filters.
Among the safest chemical filters are:
Octyltriazone, Ethylhexyl Triazone, EHT – UVB protection;
Diethylamino, Hydrobenzoyl, Hexyl Benzoate, FHHB – UVA protection, antioxidant:
Bis-ethyl-hexyloxphenol, Methoxyphenyl Triazine, BEMT, Bemotrizinol, Anisotriazine, Escalol S, Tinosorb S Aqua – UVA protection;
Tetramethylbutytl-phenol, MBBT, Bisoctrizole – UVA and UVB protection;
Mexoryl SX (Terephthalylidene, Dicamphor Sulfonic acid, TDSA, Ecamsule) – UVA protection;
Mexoryl XL (Drometrizole Trisiloxane, Ecamsule) – UVA protection.
Among unsafe chemical filters shown to be toxic or allergic are: Mexoryl SD or 3-benzylidene camphor, Oxybenzone or Benzophenone-3, 2-hydroxy-4-methoxyphenyl, Phenyl-methanone, Enzacamene or 4-methylbenzylidene camphor, MBC, 4-MBC, Parsol 5000, Eusolex 6300, Octinoxatе or Octylmethoxycinnamate, Ethylhexyl Methoxycinnamate.
How to use SPF cream?
You can choose to use a separate SPF product or find a moisturizer with a sun protection factor. It’s recommended to wear no less than 30 SPF, but ideally 50. Usually, the sunscreen works at its maximum within two hours after its application; after that, the effect starts decreasing. So ideally, the cream should be re-applied each two-three hours. Remember to take care of your neckline and hands, as these skin parts are also very sensitive to photoaging.
Note that a high UV index does not necessarily require bright sunshine as the rays can easily reach the earth's surface through clouds. It’s not only late spring-summer months when the sun is active; it happens in winter too. The best solution is to track the UV index daily; luckily, many apps are enabling that. Also note that glass, if it’s not specifically toned against ultraviolet, does not protect your skin from sun exposure.