Mineral vs Chemical Sunscreen: What's the Difference?

In practice, chemical and mineral sunscreens aren't that different in how they protect you. The real difference is in how they feel on the skin, and how your skin responds.

Chemical Sunscreen

The one most Australians grew up with. Works well, rubs in fast, gets the job done.

How it works

Absorbs UV and converts it to heat

Feel on skin

Lightweight. Sits comfortably without weight or tackiness.

Appearance

Usually invisible. Rubs in clear on most skin tones.

Common actives

Avobenzone, homosalate, octocrylene.

Reapplication

Every 2 hours, after water or sweat

Works well for

  • Daily wear under makeup
  • Active days: beach, sport, the lot
  • Those who don't like a white cast
  • Most skin types without sensitivities

Mineral Sunscreen

For skin that prefers a different approach.

How it works

Also absorbs UV, despite the common "reflects" claim

Feel on skin

Can feel heavier. Some formulas sit thicker on the skin.

Appearance

Can leave a faint cast, though modern formulas have improved.

Common actives

Zinc oxide, titanium oxide

Reapplication

Every 2 hours, and after water or sweat

Worth trying if

  • You've tried sensitive formulas and still had reactions
  • Your skin doesn't get along with chemical filters
  • You prefer a formula that stays on the skin's surface

What the research shows

You'll still see plenty of sunscreen brands say mineral filters "reflect" UV rays while chemical ones "absorb" them. The science says something different.

In late 2025, chemists at UNSW tested ten commercially available sunscreens and reviewed the ingredient lists of 143 more on Australia's TGA register. Their finding: both mineral and chemical sunscreens work primarily by absorbing UV radiation. Zinc oxide and titanium dioxide absorb UV the same way organic filters do. A small amount of scattering happens at the surface, but absorption is doing the actual work.

They also found that roughly one in three sunscreens marketed as "mineral-only" contained additional UV-absorbing compounds elsewhere in the formula.

Being chemist-operated, we notice what gets skipped. Mineral and chemical sunscreens feel different on the skin and suit different skin types. That matters more than the reflection-versus-absorption line you'll read everywhere else.

So what's in a mineral sunscreen?

Mineral sunscreens are named after their UV filters. Most of what's in the tube is the same stuff you'd find in any sunscreen.

Active UV filters

Zinc oxide, sometimes with titanium dioxide. Modern formulas use non-nano zinc oxide, which means the particle size sits above 100 nanometres.

Supporting ingredients

Emollients to help it spread, emulsifiers to keep it stable, preservatives so it doesn't spoil. The same supporting cast you'll find in chemical sunscreens.

What "mineral" refers to

The actives, not the whole formula. A "mineral sunscreen" means the UV filters are mineral. The rest of the formula is chemistry too.

Still wondering?

Is mineral sunscreen better than chemical?

Neither is better on protection. Both can be broad spectrum, both can reach SPF 50+, and both work primarily by absorbing UV. Which one suits you comes down to your skin. If chemical filters have irritated you in the past, mineral is worth a go. If you've never had a reaction and you want something that rubs in clear under makeup, chemical is usually the easier daily wear.

How does chemical sunscreen work?

Chemical filters like avobenzone, homosalate and octocrylene absorb UV radiation and convert it to heat, which your skin releases. Same mechanism as mineral filters, different chemistry.

What does "chemical free sunscreen" mean?

Not much, scientifically. Everything is made of chemicals, including water and zinc oxide. What the label usually means is that the sunscreen uses mineral actives rather than organic UV filters. Worth reading the full ingredient list either way. Plenty of sunscreens marketed as "chemical free" still contain other organic compounds that absorb UV.

Does mineral sunscreen need to be reapplied as often as chemical?

Yes. Both need reapplying every two hours during sun exposure, and after water or heavy sweat. The rules are the same regardless of which active is in the tube.

Not sure which suits you?

Answer a few questions. No wrong answers, just whatever's true for you.

Has your skin ever reacted badly to sunscreen?

Have you tried a sensitive or fragrance-free sunscreen before?

How would you describe your skin?

Some Common Myths

Some sunscreen claims stick around long past their use-by date.

Myth

Zinc sits on top of your skin and bounces UV away.

Actually

Modern zinc oxide works almost entirely by absorbing UV and converting it to heat, the same way chemical filters do. There's a bit of reflection and scattering too, but absorption does most of the job. The 'reflects UV rays' framing is old marketing language, not current science.

Myth

Natural sunscreen is safer.

Actually

Natural isn't a regulated term in sunscreen. Every TGA-listed sunscreen, mineral or chemical, has to meet the same safety standards. What matters is whether the formula suits your skin and whether the SPF and water resistance are substantiated. Not whether the word 'natural' is on the bottle.

Myth

Reef-safe sunscreen is an Australian standard.

Actually

There's no agreed scientific or legal definition for 'reef safe' in Australia. The closest actual rule is Hawaii's Bill S2571, which bans two specific chemicals (oxybenzone and octinoxate). Maxiblock formulas don't contain either. But beyond that specific claim, 'reef safe' is marketing language.

Myth

Higher SPF means you don't need to reapply as often.

Actually

Every sunscreen needs reapplication every 2 hours, regardless of SPF number. Also after swimming, sweating, or towelling off. The SPF rating tells you how much UVB the formula filters when applied at the right dose, not how long it stays on.

Myth

Sunscreen is waterproof.

Actually

No sunscreen is waterproof. Australian and international regulations only allow the term 'water resistant' with a stated duration. Our formulas are 4 hours water resistant, which is longer than most people stay in the water anyway.

Myth

You only need sunscreen on sunny days.

Actually

UV penetrates cloud cover. Up to 80% of UV still reaches your skin on overcast days, and UV levels in Australia can stay high from spring through autumn. The UV index is a better guide than how the sky looks.