Sunscreen FAQs: Hannah English
Words & images by Hannah English
About the author: Hannah English is a pharmaceutical scientist with a clinical research background. She is also known for being a beauty writer and content creator who has built a niche within the beauty industry around her passion for making science feel cool, relevant and accessible.
If you’re reading this, hopefully you know that wearing sunscreen every day is the best thing you can do for your skin. You know it’s the most important part of your skincare routine and that when used correctly, sunscreen can reduce your risk of skin cancer. It can reduce the signs of premature ageing, too, and keep your skin looking its best for years to come. Here's what you need to know to use it correctly!
How much sunscreen am I meant to use?
During testing, sunscreen is applied at a density of 2mg per square cm of skin, so applying less than that would mean you get less protection. We’ve figured it out for you, though – for face, it’s about ¼ teaspoon. We’re not just applying to our face though, are we? So for face, neck and ears, use ½ teaspoon, or a whole teaspoon for your whole head. Don’t forget your chest! For your body, apply 5mL or one teaspoon per limb.
Observational studies have shown that most people don’t apply enough sunscreen, with standard use ranging between 20% and 50% of the recommended application. Does that stress you out? Me too. More is more.
I’ve heard sunscreen is bad for me.
There’s no evidence that UV filters have adverse effects on humans at doses reflective of typical use. Although some people are unlucky enough to have skin reactions to some UV filters, think about it like this – nuts are only harmful if you have a nut allergy, right? That doesn’t mean nuts are bad for everyone.
I’m pregnant – is my sunscreen safe?
Yes. The absorption through your skin is minimal. Sunscreens aren’t a risk for pregnant and breastfeeding people. It’s also important to note that avoiding sunburn and sun damage is important when you’re pregnant, just like any other time.
I’ve heard that SPF50+ is only a little more protection than SPF30 – is that right?
The thing is, people generally don’t use enough sunscreen, and the protection you get decreases in a linear way. So if you apply half the amount you should be, you get about half the protection. That’s one reason it’s better to use the highest SPF you can get.
Now, raise your hand if you’ve been burnt while wearing sunscreen. This happens for a few reasons; firstly, not enough sunscreen was applied… fail. Secondly, a little UV still makes it through your sunscreen. If you combine that with too much time in the sun, you’re bound to burn anyway.
Let’s talk about the UV that makes it through. With an SPF15 sunscreen, you can expect protection from about 93% of UV radiation, meaning 7% makes it through. With SPF30 (applied correctly, of course), expect 96.7% protection. This means 3.3% of the radiation gets through. With SPF50+, you can expect 98% protection, meaning 2% gets through. More than enough to do some damage. Know this, I’d rather have the least amount of UV possible reaching my skin. Wouldn’t you agree?
I’m Vitamin D deficient – should I skip sunscreen?
We’ve established that some sun still gets through your sunscreen and I can confirm that in Australia, that’s more than enough to manage your Vitamin D. Besides, you can supplement Vitamin D but you can’t supplement to undo UV damage!
Why do I have to apply 20 minutes before I go outside?
Have you seen someone arrive at the beach, settle down and let their sunscreen (and their skin) cook for a bit in the sun before getting around to applying? That’s a lot of time for the sun to start sizzling their skin, right?
That’s one reason. The other reason is that sunscreen needs to dry down so it can form an even film on your skin, so there aren’t any gaps in your protection.
Why do I have to reapply?
Your body creates sweat and oil, you touch your skin, you swim and towel off, and all of these things can compromise your sunscreen’s ability to protect your skin. You’re sweating and producing oil all the time, even when you can’t feel it. You’re touching your face a lot, too! And you might have missed a spot during your first application.
Can I wear sunscreen to an outdoor event? I’m going to be photographed…
The last thing we want is a sunburn in photos, or worse, on our wedding day! Lucky for us, it’s a total myth that sunscreen causes flashback. I’ve reviewed and photographed over 50 sunscreens and didn’t see flashback at all. Not even once. So rest assured, your skin’s health doesn’t have to be ruined.
Now that you’re a sunscreen expert, make sure you supplement your protection with sunglasses, a hat, seeking shade, and covering up with clothing. I’m proud of you.
ALWAYS READ THE LABEL. FOLLOW THE DIRECTIONS FOR USE.
Apply 20 minutes before sun exposure. Sunscreen is only one part of sun protection so wear protective clothing and seek shade. Avoid prolonged sun exposure. Reapply every 2 hours and after swimming, towelling and perspiring in accordance with directions.