We all know how important sun protection is for our skin’s health - but how much do you really know about how SPF protects us from UV-related damage? We take a closer look at the many benefits of sunscreen.
UVAs, UVBs: what’s the difference?
Sunscreen packaging can often appear confusing, with multiple references to UVAs, UVBs, broad spectrum protection, and even SPF itself.
That said, we all know the benefits daily SPF brings to our skin, so it’s important to make sure you understand just what to look for in your sun protection.
UVA are responsible for
80%of biological damage
to the epidermis
While UVA rays can be divided into two types - shortform and longform - both types are longer than UVB rays.
This means that UVA rays can penetrate deep inside the dermis, causing the gradual appearance of most visible signs of photoaging.
What’s more, UVA are responsible for an astonishing 80% of biological damage to the epidermis (the skin’s outermost layer), rising to 97% in the dermis (the skin’s middle layer).
UVB rays are shorter than UVA rays. As a result, they penetrate the outer layers of the skin more easily, making them responsible for tanning and sunburn, as well as 65% of skin cancers. UVB rays are at their most powerful in summer, unlike UVAs, which are present all year round.
Finally, the SPF number indicates the level of protection against UVB rays: in other words, how long skin will be able to tolerate intense sunshine without burning. For example, SPF 15 means that skin is able to withstand approximately 15 times more UVB than normal before suffering from sunburn. However, it’s important to make sure your skin is protected from UVA damage as well. Look for the letters ‘PPD’ or the UVA logo on your bottle of sun protection to make sure you’re offering your skin the best protection possible.
Choosing the right sunscreen
Research conducted by L’Oréal suggests that UV exposure is responsible for up to 80% of preventable skin aging. Generally speaking, sunscreen falls into two main categories: physical sunscreens (also known as mineral sunscreens) and chemical sunscreens, also known as organic sunscreens. As their name suggests, physical sunscreen provides a protective covering that deflects UV rays. Common physical sunscreen ingredients include titanium oxide and zinc oxide.
Chemical/organic ingredients, meanwhile, absorb UV, reducing its ability to penetrate into the skin. Chemical sunscreens commonly include ingredients such as avobenzone,oxybenzone and homosalate.[1]
As mentioned above, whatever the sunscreen you choose, it’s important to ensure it offers “broad-spectrum” coverage. This simply means protection from both UVA and UVB rays, guarding skin against visible and invisible damage linked to UV rays.
Most day creams generally contain a good level of SPF, but if you prefer applying sunscreen separately, opt for a physical formula if you’re planning on wearing makeup. Apply before makeup to offer skin a protective layer pre-foundation. Added bonus: a sunscreen with a mattifying texture will help prime skin, creating a perfect base for your makeup.
Sources:
[1] http://www.ewg.org/sunscreen/report/the-trouble-with-sunscreen-chemicals/#.Wc5WY8hJZPY
