How to choose an SPF 50 sunscreen and what the differences between UVA and UVB mean for healthy skin.
SPF: sun protection is not only for the beach – it is one of the most important things you can do for the health and the appearance of your skin.
Ultraviolet B rays, with wavelengths between 280 and 320 nm:
• cause sunburn
• are stronger in summer
• do immediate damage
• protection against UVB is measured by the SPF
Ultraviolet A rays, with wavelengths between 320 and 400 nm:
• are present all year round (even on cloudier days)
• penetrate deeper into the skin
• cause premature ageing (wrinkles, loss of firmness)
• cause pigment spots
• destroy collagen
• increase the risk of skin cancer (melanoma, squamous and basal cell carcinoma)
• pass through glass and affect the skin even in the car or at the office
• protection against UVA is measured by the PPD
The overwhelming majority of sun protection products show the SPF on the packaging, which measures only the protection against UVB (so the higher the SPF — a maximum of SPF 50+ in Europe, SPF 100 in the US — the lower the risk of sunburn), but the real enemy of the skin is UVA radiation.
For effective UVA protection you should look for:
• broad spectrum
• PA ++++ (the highest level of UVA protection)
• the UVA circle symbol (the European standard)
• PPD (persistent pigment darkening)
So if we want to prevent actinic ageing and reduce the risk of pigment spots and skin cancer, UVA protection is not negotiable.
How do we know which sunscreen suits our skin type?
First of all, turn your attention to the dermocosmetic products sold in pharmacies. The major dermatocosmetic brands have sun protection products for dermatological conditions (such as vitiligo, lupus and so on) as well as products with light, elegant textures suited to every skin type (oily, normal, dry, sensitive, allergic and so on).
If your skin is oily and prone to acne, look for products that are:
• Oil-free
• Non-comedogenic
• Gel or fluid in texture
• Matte in finish
• Zinc oxide, if your skin is sensitive
It would be wise to avoid rich creams, formulas based on coconut butter and very thick mineral pastes, especially if your acne is active.
If your skin is dry, look for products:
• With a cream or lotion texture
• With hyaluronic acid
• Glycerine
• Ceramides
• A luminous finish
If your skin is sensitive and/or you have rosacea, look for products:
• The best solution is mineral sun protection (mineral filters sit on the surface of the skin and reflect ultraviolet rays, but have the aesthetic drawback of thick creams that leave a whitish cast on the skin because of the zinc oxide)
• Mineral products work immediately, unlike chemical filters, which need 15 to 20 minutes before exposure
• Zinc oxide, titanium dioxide
• Fragrance-free
• Alcohol-free
• Tinted versions reduce the white-film effect
If your skin is prone to hyperpigmentation or melasma, look for products:
• With very high UVA protection
• PA++++
• SPF 50+ with broad spectrum
• Tinted products with iron oxides (which also block visible light)
Sun protection products for the body can be denser and used in larger quantities. For everyday, urban exposure you can choose SPF 30–50 with light textures that do not stain clothes, to apply to the neck, the décolletage and the hands; but for the beach and for outdoor sports choose SPF 50+ products, water-resistant, and reapply every 2 to 3 hours.
SPF sprays are convenient but do not protect well enough, so use them as a supplement during long exposure when you cannot reapply the cream.
How much should be applied for effective protection?
The SPF tested in the laboratory (SPF 30, 50 and so on) only works if you apply the right amount.
! Most people apply only 30 to 50% of what they should, so that an SPF 50 can drop to a real protection of SPF 20–25.
For the face and neck, use the two-finger rule: squeeze the tube and apply product along the length of two fingers (usually the index and middle fingers) or, for more fluid products, about a quarter of a teaspoon. Reapply every 2 to 3 hours if you are outdoors.
! Places where we forget to apply SPF and where it is very important to protect the skin from ultraviolet radiation: the ears, the backs of the hands, under the chin, and the scalp in men with hair loss.
Here is a sensible checklist before you buy:
• Is it broad spectrum?
• Is UVA protection clearly stated?
• Does it suit my skin type?
• Will I enjoy using it every day?
The best SPF is the one you actually apply every day.