Sunscreen Labels: Understanding UVA, UVB, and SPF

December 02 2014 – Raji Kalra

 

I’ll start off by saying, I love the sun. When Nancy Toran, Kristen Rogers and I were in California just a few months ago, I kept thinking how wonderful it is to wake up every morning and see a bright blue sky and the sun shining. It was glorious. Now that the Spring is here in Canada, we are all looking for that great go-to sunscreen. I’m going to keep it simple and go over some few basics.

UVA/UVB:When you are looking at any sunscreen, it should specify UVA/UVB Broad Spectrum on the label. This is because there are 2 types of UV light that are harmful, and you need protection from both. UVA rays will cause wrinkling, age spots and are harder to block with sunscreen ingredients. UVB rays will cause sunburns and are the primary cause of non-melanoma skin cancer.

SPF: A product’s SPF (Sun Protection Factor) rating is a measurement of how long it will take you skin to sunburn with sunscreen on, in comparison to skin that has not been treated with sunscreen. Also, note that if it’s labelled with only blocking UVB (that causes sunburn), it does not measure the damage from UVA rays which penetrate deeper into your skin. Ouch!

In theory, the higher the SPF number the better protection from sun damage. However, this is not necessarily true. According to the Environmental Protection Agency, when a sunscreen is properly used a SPF of 15 protects skin from 93% of UVB damage and a SPF of 30 protects the skin from 97% of UVB damage. As you can see, doubling your SPF does not double your protection.

Please see the chart below showing how much more UVB protection you’ll get as the SPF number increases. Not that logical right?

EPAgovfigure1

SPF vs. UVB Protection Chart from EPA Gov.

Personally, I look for an SPF of 30 with UVA/UVB protection in a sunscreen, and will buy a tinted moisturizer with an SPF of 15. Next blogpost we’ll get into some of these product ingredients!

Wishing everyone a beautiful sun protected day!

Patricia/Shoosha