How SPF Really Works

There’s no better time to hit the beach and soak up the sun than during summer. But this year, the sun has been so scorching hot that your skin feels like it’s being fried. And with the local weather bureau warning of hotter days ahead, it’s easy to choose to stay indoors where you can turn the air-conditioning on to full blast and instantly cool off. But really, where’s the fun in that?

Thankfully for sun worshippers, there are products that can help protect your skin from getting dry and dark and more importantly, help prevent premature skin aging and skin cancers. But how does one choose from all the products available in the market?

Know the enemy.
Part of sunlight is ultraviolet (UV) radiation. It’s classified into three: UVA (long-wave rays), UVB (shortwave rays) and UVC. UVC rays are so short they’re absorbed by the ozone layer and don’t reach the earth. Meanwhile, UVA rays are less intense than UVB but they’re more prevalent and penetrate the skin more deeply. UVA rays mainly cause skin aging and wrinkles while UVB rays cause reddening and sunburn. Both contribute to the development of skin cancers.

Also read: Say Goodbye To Age Spots

The real deal about SPF.
If you think the sunscreen with the highest sun protection factor (SPF) is the best in shielding you from UVB rays, you’re wrong. A product with SPF 24 is equally as effective as another with SPF 90. The difference? The number of minutes you’ll be covered. Jules Gollayan, brand manager for Vaseline shares with us how their team at Unilever computes for this. “Our technical team tells us to multiply the SPF by 10. For example, SPF 24 times 10 is 240. That’s the number of minutes that you can be under the sun because you’re protected. That’s already four hours.”

For everyday, it’s best to use a product with at least SPF 15. If you’re fair-skinned or will be exposed to outdoor activity for extended periods, use a product with a higher SPF and re-apply every few hours or after swimming or excessive sweating.   

Now if you use a number of products, each with their own SPF, they don’t add up to more sun    protection. For instance, a moisturizer with SPF 30 applied under a foundation with SPF 15 doesn’t mean you have SPF 45 protection. You’re actually covered by the product with the higher SPF.

Also read: Summer-Proof Your Skincare

SPF protects us from UVB rays but what about UVA rays?
Not all sunscreens indicate UVA protection because there’s no international standard. Here in Asia, we use the “PA” rating system to measure protection from UVA rays. This system ranges from PA+ (the least protection) to PA+++ (the most protection). Look for the PA rating on the label of your sunscreen.

Not all sun protection comes in a bottle.
Your clothes are actually added SPF! But stay away from dark and lustrous outfits that reflect more UV radiation. Go for linens and cottons in cool pastels. And don’t forget your sunnies and your hat! They help protect the sensitive, sun damage-prone areas on your head, neck and around the eyes. If you’ve got an umbrella, even better! Gollayan tells us that according to a dermatologist test, an umbrella gives you an additional SPF 6.

Also read: How To Stay Safe Under The Sun