Summer is coming, oh yes it is. While sunscreen should be an all-year affair, summer is definitely the season you start to think most about using it… and when that happens you start to ask yourself questions like, how much sunscreen should I apply to my face and neck? What does SPF 30 mean? What is the best sunscreen for sensitive skin?
Do you have more? I have you covered my friend with the answers to these 10 most commonly asked sunscreen questions. Get reading for skin safe sun love.
1. What does SPF 50 mean?
…or what does SPF 30 mean? Once you understand one, you’ll have the others covered – promise. SPF is short for sun protection factor. It’s a way of measuring the amount of UVB light (the light that causes sunburn) that a sunscreen will protect you against.
It works roughly like this…
If it takes you 10 minutes to burn in direct sunlight, using a sunscreen with SPF50 will allow you to stay out for 50 times longer e.g. 500 minutes or just over 8 hours.
How did I work that out? Well, it’s easy once you know how, just times the number of minutes it would usually take for you to burn by the rating of SPF.
e.g. 10 x 50 = 500
Now let’s take SPF 50 vs. 30… If it takes you 10 minutes to burn and you use a sunscreen with SPF30, you’ll be able to stay out for 30 times longer, e.g. 300 minutes or 5 hours.
The SPF rating of a sunscreen also tells you how many UVB rays will get to reach your skin.
An SPF of 50 allows only 1 in every 50 rays through. An SPF 30 allows only 1 in every 30 rays through. UVB rays are the ones that cause you sunburn, so these 2 ways of looking at SPF ratings, mean the same thing for your skin.
To get the savvy on all SPF ratings, be sure to download this free 1-page crib sheet to understanding sunscreen lingo.
2. Can you mix sunscreen with body lotion?
Or, is mixing sunscreen with foundation safe? Can I mix sunscreen with moisturiser?
Great questions my friend, applying sunscreen can feel clunky, so this is a super common ask. Mixing sunscreen with a body lotion or moisturiser or even foundation makes things a bit easier eh, but does it work?
The most important thing to know when using a sunscreen is that it needs to be applied at a certain thickness to do the job. SPF 30 is only SPF 30 if you use it in the right amount.
We’ll get onto exactly what this amount is in another question very soon.
When you mix sunscreen with body lotion or any other moisturiser (or even water!) you dilute the formula, that means you have to use even more to get the required SPF.
Bottom line – when you mix SPF with moisturiser you dilute its sun protection factor and you have no idea of knowing whether you’ve created SPF 12 or SPF 2.
Instead, you could make your sunscreen easier to apply by using a lower SPF more frequently, or by choosing a spray on sunscreen. If you’re not sure where to start or if your current sunscreen is the best fit for you – i’m here to help.
3. What is the difference between chemical sunscreen and physical sunscreen?
This is where science words can boggle your mind, don’t worry, this is really, really straight forward. Neither are scary.
Chemical sunscreens are made from ingredients that are able to absorb the damaging energy of UV light. They don’t get to play with your skin because they’re absorbed well before they reach it. Because chemical sunscreens interact with UV light by absorbing it, they get used-up. It’s like flour, water and yeast being baked to make bread, once it’s reacted, it’s not coming back to be flour, water and yeast ever again.
On the other hand physical sunscreens (most commonly called sunblock) like zinc oxide and titanium dioxide also work by behaving like a shield. When a UV ray reaches a physical sunscreen part of it can be deflected away, it bounces back, it goes back out into the universe. For this reason, physical sunscreens tend not to get used up as fast as chemical ones can. Although, this doesn’t mean you don’t need to reapply, as they can also be rubbed off by clothes, beach towels, water and sweating.
4. How much sunscreen for face and neck?
Fantastic question. Your face and neck should enjoy sun protection 365 days a year – more about why very soon. When sunscreens get tested for their SPF ratings, they travel to a laboratory, get spread at a set thickness onto a plastic, square plate. Then, this plate gets UV light shone onto one side. On the other side of this plate, there’s a UV detector… and you guessed it, depending on how many UV rays travel through, determines the SPF rating given to the sunscreen.
The magic number my friend is 2mg/cm2.
For an average face size, this is a quarter teaspoon. Measure it out, have you been using enough?
— Cheryl Woodman (@HonestyForSkin) 2 May 2017
For, face and neck, scale up. Averagely this is going to be around 2 quarter teaspoons, or in other words, a half teaspoon. Bingo. Sorted.
5. Why do sunscreens make my face white?
This my friend is ‘white cast’. Aka the Casper affect. White cast is used to describe the whitening effect of some physical suncreams. It happens because physical sunscreens are made up from tiny, tiny, light reflecting particles of zinc oxide and titanium dioxide, which are both white.
Titanium dioxide is even added to some body lotions and creams to make their colour ‘white-white’ instead of their natural yellow-cream colour.
This white cast effect is more pronounced if you have darker skin or as you catch a tan.
The solution: Try a chemical sunscreen without physical sunscreen filters or look for nano zinc oxide sun creams. These sun creams have very small particles of physical sunscreen which makes their white look, less white – some can even be ‘invisible’.
6. What SPF should I use on my face?
There’s a couple of answers to this question.
- The higher the SPF the better (until you get to about SPF 50, or even SPF 30 in my opinion – keep reading to find out why)
- The higher your UVA protection, the better (if you’re not sure about the difference between UVA & UVB light, be sure to download my free 1-page guide to sun protection here).
Now, let’s break this down.
A higher SPF is always better, especially for your face. Your face is tuned to the sunshine every day. It’s even absorbing pesky UV rays when there’s cloud cover about.
Note to the wise – cloud cover does not mean you’re safe from the effects of the sun. As a benchmark, SPF 30 is usually what’s advised by dermatologists as a recommended minimum. An SPF of 30 means your skin is protected for 30 times longer than its own protection would normally allow for. It also means only 1 in every 30 UVB rays are able to say hello to your skin. And it finally means you have around a 97% protection level.
When you ramp up to SPF 50, your skin is protected for 50 times longer, with only 1 in every 50 UVB rays reaching your skin giving you a protection percentage of 98%.
See that small jump from 97 to 98%?
This is the reason why I recommend SPF 30-50 for use on your face – above SPF 50 the pay-off isn’t huge. You’re talking 0.5% extra.
Now answer number 2 – what SPF should I use on my face? There’s a part of this question missing…
SPF only rates your skin’s protection against UVB light, but UVB light does not come alone. Oh no – UVB light brings friends and in this case we call that friend UVA light.
UVA light is sneaky because it doesn’t often cause a sunburn, however it is responsible for collagen damage, age spots, fine lines and wrinkles. Yeek!
When choosing an SPF for your face, be sure it’s also protecting you against UVA light.
How do you tell?
If you’ve downloaded that free 1-page to sunscreen lingo cheat sheet you’ll already know – go you dear friend.
The 3 UVA ratings to watch for are…
Sun protection is the cheapest anti-aging cream you can buy – go enjoy dear friend.
7. Can you get burnt in the shade?
The sun’s beating down and you’re noticing a glowing of your skin that isn’t golden – in fact it’s almost definitely ripening to lobster red. What do you do?
Do you apply more sunscreen? or… do you seek shade?
When lobster red’s close to visiting, option 2 seems the best one eh. Time for shade, white wine and seafood!
But… are you protected in the shade? Can you get sunburned in the shade?
Great questions my friend.
First answer (the non-technical one) – you are less likely to get sunburnt in the shade, but your skin is still at great risk of sun damage and premature ageing.
Second answer – the semi-technical one – UV light can reach you directly or indirectly, aka it bounces off things. Which means even in the shade, your skin’s still interacting with UV light. Now when it comes to UVA, some estimate up to 50% of UVA light is still present when your in shade cover – that’s a heck of a lot. This is the light you’ll see the effects of later in life. You’ll see zilch today, then 15, 20, 30 years down the line, you’ll begin to see age spots, fine lines, wrinkles and more.
Hmmm… worth protecting against eh.
8. Can you get sunburned through clouds
Wherever you can see your hand, there’s light reaching planet earth. When it’s dark and you can’t even see your nose, there’s none.
Which means, even when there are clouds, there’s still light reaching earth.
…and when there’s light, there’s also UV light. Now of course, when it’s cloudy, it’s always a tad darker, which yes, in most cases means there is less light than normal.
The U.S. National Weather Service and Environmental Protection Agency estimate that for scattered clouds (kind of like ‘mackerel sky’) around 89% of UV light is able to pass through, for broken cloud conditions, 73% and for those dreaded overcast days – 32%.
Now this is the case most of the time. But there’s something else you should know about and it’s called;
Sometimes UV light can actually be powered up by cloud cover. Remember how we said light can bounce off things? Well this is the theory of cloud enhancement, it’s a bit like concentrating light with a magnifying glass to make fire (warning: don’t try this at home!).
This doesn’t happen often, sometimes only for a few minutes, sometimes for an hour. When it does, your UV light exposure could be up to 75% higher. Crazy ‘eh.
The bottom line: Yes, you can get sunburned through clouds – wear sunscreen daily, even when it’s overcast.
9. Can sunscreen replace moisturiser? Do I need moisturiser and sunscreen?
Such a great question – yes, the right sunscreen can replace your moisturiser. This is when you might end up paying a little extra on a sunscreen that can do the jobs of 2 products. More on 1, less on 2.
Most drugstore bought, basic sunscreens will not replace your moisturiser. They usually have a basic formula that’s like a bargain basement chocolate cake with 10% cocoa solids, no chocolate sprinkles and no strangely intriguing silver frosted balls. Their job is 1-fold – to protect your skin.
Now, pay a little extra and you’ll get a 50% cocoa solids cake with chocolate sprinkles and silver frosted ball – one of my all-time favourites is Paula’s Choice Calm Mineral Moisturiser SPF 30.
10. The best natural sunscreen for sensitive skin
Sunscreen for sensitive skin is most sensitive when using only physical sunblock filters. Rewind to question 3 to swat up on the difference. If you have skin conditions like eczema, rosacea or acne this answer is for you dear friend.
Physical sunscreen filters don’t tend to break down into the complex ingredients chemical filters can. It’s the breakdown products of chemical sunscreen filters that can irritate your skin. Sometimes they can also form photosensitisers – as your skin reacts to these actives it can look like you have heat rash.
When choosing a natural sunscreen for sensitive skin, there’s 2 actively UV protecting ingredients that will be listed – zinc oxide and/or titanium dioxide.
If you see any other ‘active’ ingredients, the sunscreen you have in your hand is made from both physical and chemical sunscreens.
Did I answer all your sunscreen questions my friend? Come tell me in the comments which sunscreen you use now and what you love most about it – I’m excited to find out.
Oh and use that green button below to forward this blog onto all the friends you love dearly. Help keep them sun safe. You are the best.
Cheryl Woodman is a scientist & award winning skincare formulator who’s more friend next door than bow tie wearing professor. As creator of Honesty For Your Skin her aim is to help you care for your skin in the best ways possible. She’s founder of the natural & fragrance free skincare brand Honesty while also hosting 1 to 1 skincare coaching to help you get your best skin yet. Find out more here.