How Much SPF Your Sunscreen Should Have
When you’re faced with lots of sunscreen options, it’s easy to be overwhelmed by all the different types and brands. But the first thing that really matters is the SPF.
Let’s talk about what is the minimum SPF you should be reaching for next time you buy sunscreen.
What is the Sun Protection Factor?
When looking at a sunscreen bottle, we know a high SPF is good, but maybe not why it’s good. By understanding what SPF measures, we can decide how much is right for us.
SPF is an acronym for Sun Protection Factor, a measurement of how long it takes someone to burn with and without the sunscreen. This is learned by applying the product on a participant and comparing the length of time it takes protected and unprotected skin to burn under a UV lamp.
An SPF of 10, for example, means that it took participants in that sunscreen’s tests 10 times longer to burn while wearing it and thus protects from 90% of sunburn-causing UVB rays.
Obviously, the higher the SPF, the longer you could theoretically go without burning and the more protection you are getting from damaging UV rays.
So what SPF is enough?
The FDA seems to think that SPF 15 is required according to its sunscreen regulations, but most dermatologists and skin cancer specialists conclude that SPF 30 is the minimum to truly protect against damage. Those with lighter skin tones are advised to wear higher SPF sunscreen and to wear it and reapply it more often.
Is any sunscreen ok?
Another thing to consider is whether or not the sunscreen is broad spectrum. This is where in addition its SPF rating (and thus its UVB protection) it also filters a proportional percent of UVA rays. UVA does not cause sunburns, but travels through glass and contributes to tanning, ageing and skin cancer. For protecting yourself completely, broad spectrum sunscreen is key.
Every continent has a different way of denoting broad spectrum UVA protection on their sunscreen bottles.
What should you look for?
In the US and Australia, these sunscreens must have the words “Broad Spectrum” on the front of the bottle.
In Europe, there is a circle with ‘UVA’ printed inside it, used as an indicator of a sunscreen that offers 1/3rd UVA protection for the SPF rating. This means it’s broad spectrum.
In Asia, the letters ‘PA‘ followed by some ‘+’ signify show the UVA protection. You want to aim to get a sunscreen that is labelled +++ or ++++ for maximum protection.
Is higher always better? What about SPF 70 or 100 or even higher?
The lines become blurred once you get above SPF 50, and that is why Australia has disallowed labelling over this number (and the US is also attempting to at the moment).
SPF 50 AND SPF 100 protect from a very similar percentage of rays – 98% vs 99% respectively. You need to be reapplying sunscreen more regularly than these sunscreens will protect you for anyway! For example, if you burn naturally in 10 minutes, an SPF 50 will protect you for over 16 and a half hours, but reapplication should happen every two hours so it’s essentially pointless.
They also tend to be thicker and less cosmetically elegant, meaning you might apply too thin of a layer and won’t want to wear them as much.
An SPF 30+ Broad-Spectrum (with the UVA circle or PA+++ where applicable) sunscreen is plenty for most people in everyday situations. You should be able to find a range of these at any local pharmacy or store. Use it every day as part of your skin care routine!
See you next time,