Suncare

UV Index - Effects on the skin

What are the major differences between UVA and UVB rays?

Ultraviolet rays are emitted by the sun, which then interact with the skin. These rays can be divided into two groups:

Ultraviolet B (UVB) and Ultraviolet A (UVA) rays. UVBs (B for burn) account for 5% of UV rays to reach the earth’s surface. They are filtered by glass. They penetrate the epidermis, or upper layer of the skin. They cause: “sunburn” (our built-in warning system), tanned skin and in the long term, certain types of skin cancer.

UVA (A for aging and allergies) account for the remaining 95% of UV rays to reach the earth’s surface and are only partially filtered by glass. They penetrate deeper into the dermis or base layer of the skin causing premature skin aging (wrinkles, dark spots, etc…), DNA destruction and even skin cancer. UVA rays are more dangerous than UVBs because, unlike the sunburn caused by UVBs, our body does not have a natural warning system against them. By the time the damage they cause becomes visible, it is already too late. UVA rays also can cause Lucitis or “sun allergy”, an extremely itchy rash that appears on the arms and upper chest on initial exposure to the sun.

To guarantee total efficacy, a sun protection product must provide lasting protection against both UVA and UVB rays.

How do UVA and UVB rays affect my skin?

The risks vary, depending on the skin type and exposure. In fact, each of us has a genetically-defined, different skin phototype which conditions the risks of sunburn, photo-aging and skin cancer caused by exposure to the sun. Other environmental factors such as geographic locations, season, time of the day, climate, altitude and reflection of the sun’s rays (from sand, water or snow) also play a major role.

Does SPF measure only UVB Protection?

Yes this is true. SPF (Sun Protection Factor) is an indication of the level of sun protection provided by the product with regards to UVB rays. Today, there is still not an official standard for measuring UVA protection of a sunscreen and consumers have no accurate way of knowing the effectiveness of UVA filters. Many sunscreens on the market only deliver UVB protection, therefore, only protecting against sunburn not against skin aging and skin cancers. Although sunscreen labels often advertise “full spectrum” or “broad spectrum” properties, meaning that they block both UVA and UVB rays; companies can make this claim without specifying how well these products protect against UVA rays.

What is the difference between filters and screens?

Filters are chemical in origin and absorb UV rays. Screens are mineral and consist of micro particles which reflect the sun’s rays. A combination of the two provides comprehensive protection against both UVA and UVB rays. The ANTHELIOS ®XL products offer both: filters and screens.

What is Mexoryl ®XL and what makes this sun filter so special?

Click on La Roche-Posay Anthelios XL to learn about this exclusive patented photostable filtering system developed by La Roche-Posay Laboratory for its Anthelios ®XL suncare line.