Q: There are so many sunscreens out there to choose from. How will I know which is best suited for my skin type and can effectively block both UVA and UVB rays? What do the SPF ratings (SPF 30, SPF 50, etc) mean?
A: I am delighted to answer your question because sunscreens are among my favorite skin care products. I recommend sunscreen as an essential part of basic skin care. Here’s why.
The sun emits three kinds of ultraviolet rays – UVA, UVB and UVC. These UV rays are invisible – they are different from the sunlight that you see and different from the heat that you feel.
UVA has the longest wavelength, can penetrate deeper in the skin, and can cause photoaging (A for aging). UVB causes sunburn (B for burning). UVC is highly carcinogenic. Our ozone layer blocks UVC rays from reaching the earth’s surface. Most importantly, UV radiation has been implicated in the development of skin cancers.
You are correct in looking for a sunscreen that has both UVA and UVB protection. Certainly, we don’t want to prevent sunburn alone but we’d like to delay aging as well. And it goes without saying that we don’t want skin cancers!
The SPF rating on sunscreen bottles only refers to UVB protection. SPF 30 – 50 fall in the same bracket of “high protection” against UVB. SPF 50+ on the other hand provides “very high protection.” In Europe and Australia, it is unlawful to label sunscreens as having SPF higher than 50+. Higher SPF ratings provide little added protection, and give people a false sense of security.
Unlike UVB, there’s no standard rating for UVA protection. Some companies use “star ratings” while others use UVA protection factors. A high SPF does not mean that the PFA is high too. You need to read the labels and choose broad spectrum protection. Your best bet would be physical sunscreen made from minerals such as zinc oxide and/or titanium dioxide. They are safe and stable under sun exposure.
Choosing the right sunscreen is just the first step. There are other issues that we need to know regarding sunscreen use – how much to apply, how often, which formulation is best (e.g. cream, powder, spray), and most importantly why.
Written by: Dr. Isay. She is a graduate of UP College of Medicine and had her residency training in Dermatology at the same institution.