chemical vs physical sunscreen

Chemical VS physical sunscreen: which team are you on?

Yep, not all sunscreens are created equal. Some go on like a dream while others are as thick as toothpaste and leave a white mask on your face to boot.

I used to think someone at the lab had screwed up if I got a gooey mess. Now I know they were just trying to do their best with what they’ve got.

Truth bomb: some of the best UV filters are a pain to work with. Typical, isn’t it? But that doesn’t mean you shouldn’t use them.

Sure, you want a sunscreen that’s aesthetically pleasant. But that’s not the whole story. Here’s everything you need to know about chemical and physical sunscreen and how to choose the best one for you:

ultrasun family spf 30 review

Chemical VS Physical Sunscreen: Which UV Filters Do They Use?

CHEMICAL SUNSCREENSPHYSICAL SUNSCREENS
AvobenzoneTitanium Dioxide
HomosalateZinc Oxide
Mexoryl SX and XL
Octinoxate
Octisalate
Octocrylene
Oxybenzone
Tinosorb S and M
Uvinul A Plus and T150

A sunscreen is physical (a.k.a. mineral) if it uses only minerals zinc oxide and/or titanium dioxide, as UV filters.

If it only uses the UV filters in the first column, it’s a chemical sunscreen. And if it uses both, it’s a hybrid.

NOTE: ALL sunscreens are technically chemical. That’s because everything that’s made of matter – including water, minerals, and literally every skincare ingredient – is a chemical. Here, we’re using the word “chemical” for sunscreens that don’t use mineral filters.

Related: What Are The Best Sunscreen Ingredients?


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Chemical VS Physical Sunscreen: How Do They Work?

CHEMICALPHYSICAL
They absorb UV raysThey absorb UV rays
They reflect away UV rays

You probably heard that chemical sunscreens absorb UV rays while physical sunscreens create a shield on the skin that reflects UV rays away from it.

That’s not entirely true. Let me explain.

ALL sunscreens work by absorbing UV rays and transforming them into a less damaging form of energy (heat).

The difference? Chemical sunscreens ONLY work in this way. Physical sunscreens absorb and transform MOST UV rays. The rest (long UVA rays above 360nm), they reflect away from your skin.

Related: 5 Myths About Mineral Sunscreens You Need To Stop Believing Right Now

paula's choice super-light daily wrinkle defense spf 30 review

Chemical VS Physical Sunscreen: What Are Their Benefits?

CHEMICALPHYSICAL
Lightweight textureThey’re gentler on the skin
Don’t leave a white cast behindMore stable
Broader protection

If texture is important to you, get yourself a chemical sunscreen. Cos no matter how awesome a sunscreen is, if it feels too greasy or makes you look like a ghost, you ain’t gonna use it.

Chemical sunscreens feel so lightweight on the skin, absorb immediately and leave no tell-tale white sign behind. That’s why they’re so popular even in our chemophobic age.

Sensitive skin? You’re better off with a physical sunscreen. For starters, they’re gentler on the skin. They rarely cause allergies and irritations. In fact, they’re so safe, even babies can use them!

I recommend zinc oxide. It protects, on its own, from the entire UV range. Compare that with chemical UV filters. Each of them protects either against UVA or UVB rays. Usually, you need 4 or 5 to keep you safe from all UV rays. The more you use, the higher the chance of an irritation!

There’s another reason why physical sunscreens are better. They’re more stable, so they take longer to degrade in the sun.

Here’s the deal: as UV filters do their duty and absorb/transform/reflect UV rays to make them harmless, they lose a bit of their effectiveness. After 2 hours in the bright sun, most sunscreens are useless. That’s why you need to reapply them often.

Mineral UV filters degrade a little slower than their “chemical” counterparts, so they keep you protected for that little bit longer (but you still need to reapply them often).

Related: How Often Should You Reapply Sunscreen?

Chemical Vs Physical Sunscreen: What Are Their Disadvantages?

CHEMICALPHYSICAL
More likely to irritate sensitive skinLeave a white cast behind
More unstableCan be greasy
Can generate free radicals
Protect either from UVA or UVB rays

Let’s examine all the disadvantages of chemical sunscreens one by one, shall we?

  1. More likely to irritate sensitive skin: I’m not sure why this happens but UV filters like avobenzone and oxybenzone are known allergens. If you react badly to a sunscreen, one of these filters is usually the culprit.
  2. More unstable: They degrade quickly under sunlight. For example, avobenzone lasts less than 2 hours on its own. To make it effective for longer, you need to add other UV filters that can help stabilise it. Problem is, more UV filters, more risk of irritation.
  3. Some UV filters generate free radicals: Free radicals are the nasty molecules that give you wrinkles and dark spots. Octocrylene can generate them. But hey, at least you can fix this by adding an antioxidant serum to your routine (antioxidants neutralise free radicals).
  4. Usually protect only from UVA or UVB rays: UV filters are one tricky ponies. You have to use a bunch of them to get broad spectrum protection. Again, the more filters you use, the higher the chance of irritation.

PRO TIP: If you go chemical with your sunscreen, make sure it has avobenzone, mexoryl or tinosorb. If it doesn’t, it won’t protect you from UVA rays.

Physical sunscreens have only one downside (and it’s a big one): their texture.

Both titanium dioxide and zinc oxide are thick white minerals so they don’t spread as easily and can give your face a white tint. That makes it hard to apply the generous amount you need to keep your skin safe.

It’s true formulas are getting better. You can find lightweight physical sunscreens that don’t turn you into Caspar The Ghost after he accidentally bumped his head into a frying pan.

But these are still the minority. If texture’s that important to you, go chemical instead.

PRO TIP: If you can’t stand the white cast, go for a tinted physical sunscreen.

blissoma phototonic facial sunscreen + daily moisturizer SPf 25

Chemical Vs Physical Sunscreen: Which One Is better?

I’m team physical all the way. I love how gentle, yet effective they are. Plus, my skin is so pale, the white cast ain’t a problem for me. But I know lots of experts who favour chemical sunscreens. Again, it’s all because of the texture. If you don’t dig that, you won’t use it.

Do you prefer chemical or physical sunscreens? Share your thoughts in the comments below.