SPF can seem like a riddle at times and especially when it comes down to choosing the best sun cream for you in order to prevent skin damage from those harmful rays. Is SPF 15 worth it? Is SPF 50 too much? Do I even need to wear an SPF? (Err, yes!) So, we’ve tried to make it a little easier for you to understand so you can stay safe in the sun this summer and all year round.
What is SPF?
SPF is short for ‘Sun Protection Factor’, which is a measure of how long a sun cream will protect you from sun exposure, and particularly the ultraviolet B (UVB) rays. UVB rays cause sunburn and damage to the outer layers of skin (epidermis), contributing to the most common forms of skin cancer and sun-related skin damage.
UVA rays are the other type of skin damaging sunrays that penetrate through the outer layer of skin to the dermal layer. This is where new skin cells are formed and where your skin tans. UVA rays can damage new cell formation, skin collagen and elastic tissues, and it’s the damage to these tissues that can give skin that leathery, aged look if you experience a lot of sun exposure.
Unfortunately, sun creams don’t block UVA rays unless they are broad-spectrum (protect against both UVB and UVA) and contain compounds like zinc oxide that block most sunray penetration.
Which SPF has the best protection?
To get a better understanding, here’s a break down of the SPF scale and just how effective each is:
- SPF 15 blocks 93% of UVB rays
- SPF 30 blocks 97% of UVB rays
- SPF 50 blocks 98% of UVB rays
You may be surprised to see that there actually isn’t a great deal of difference between each SPF level. A lot of people believe that wearing an SPF 30 is double protection compared to an SPF 15, however, that isn’t actually the case.
One way of looking at this is that SPF 30 sun cream only gives you 4% more protection than an SPF 15 sun cream. Or, another way of looking at it is:
- SPF 15 (93% protection) allows 7 out of 100 photons through
- SPF 30 (97% protection) allows 3 out of 100 photons through
- SPF 50 (98% protection) allows 2 out of 100 photons through
So, while you may not be doubling your level of protection, an SPF 30 will block half the radiation that an SPF 15 would let through to your skin.
If the science seems a little confusing to you, the basic answer to this question is that most dermatologists recommend using an SPF 15 or SPF 30 sun cream, depending on how long you’re out in the sun and at what time. The sun is at its strongest and most likely to cause damage to your skin between 10am and 4pm. If you’re only nipping out for a few minutes or couple of hours in the day, an SPF 15 will help to reduce likeliness of sunburn.
However, if you’re planning to be outside for a good few hours or whole day, whether you’re sunbathing, working, going on a walk or even sat out in a beer garden, an SPF 30 should be more beneficial.
Apply sun cream 15 minutes before sun exposure so that your skin has time to soak it up. Also, do make sure to re-apply it every two hours and each time after your skin gets wet – even if your sun cream claims to be waterproof!
Why not use a really high SPF?
Sun creams with really high SPFs, such as SPF 75 or SPF 100, don’t offer much more of a greater protection than an SPF 30 would. They’re quite misleading as a lot of the time people think they have more protection than they do, when they only actually have a minor extra percentage.
Also, in order to have the broad-spectrum protection, the UVA protection should be at least 1/3 of the UVB protection. High SPF sun creams usually offer far greater UVB than UVA protection, which also offers a false sense of ‘full protection’.
While it’s extremely important to protect ourselves from UV rays by using SPF, do remember that some sun exposure can be good for us. A small amount of time in the sun helps us to generate vitamin D, which is an essential component to our bone formation. So you don’t have to completely hide away from the sun, but make sure to be smart and safe!
We hope you’ll be protecting yourself with the best SPF levels from now on. Want to know some natural ways to look after your skin in the sun? Read up on our blog post tips and DIY home remedies for looking after your skin in summer. And if you’re looking for tips to soothe your skin after sun exposure, our contributor Nyawira has some great tips for you on the natural ways to treat your skin after being out in the sun in our Summer 2017 Holiday issue.