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 how they feel on the skin, and how your skin responds.

Chemical sunscreen Mineral sunscreen
How it works Absorbs UV radiation and converts it to heat, which your skin releases. Also absorbs UV and converts it to heat. A small amount of scattering happens at the surface.
Common actives Avobenzone, homosalate, octocrylene. Zinc oxide, sometimes with titanium dioxide.
Feel on skin Lightweight. Sits comfortably without weight or tackiness. Can feel heavier. Some formulas sit thicker on the skin.
Suits Most skin types without sensitivities. Skin that reacts to chemical filters.

Water resistance and SPF figures apply to Maxiblock formulas and only where stated on the label.

How each type works in practice

Maxiblock Essential SPF 50+ sunscreen rubbed into skin, no white cast

Chemical Sunscreen

The one most Australians grew up with.

How it works

Absorbs UV and converts it to heat

Works well for

  • Ultra-light wear under makeup
  • Active days: beach, sport, the lot
  • Those who don't like a white cast
Maxiblock Mineral Clear Zinc SPF 50 sunscreen applied to a forearm

Mineral Sunscreen

For skin that prefers a different approach.

How it works

Also absorbs UV, despite the common "reflects" claim

Worth trying if

  • You've tried sensitive formulas and still had reactions
  • You want the shortest active ingredient list you can get
  • A GP or dermatologist has pointed you towards zinc

What is chemical sunscreen?

Chemical sunscreen is sunscreen whose active ingredients are organic UV filters, carbon-based molecules like avobenzone, homosalate, octocrylene and octisalate. They absorb UV radiation and convert it to heat, which your skin releases. Zinc oxide does the same job with different chemistry.

It's what most sunscreens on Australian shelves use, and what most of us grew up with. The filters dissolve into the formula rather than sitting in it as particles, which is why chemical sunscreens tend to rub in clear and feel lighter on the skin.

The usual reason people move away from them is a reaction. Some skin doesn't get on with particular organic filters, and stinging or redness is the sign. If that's you, a fragrance-free sensitive formula is worth trying before you go to zinc.

Everything else stays the same. Broad spectrum, SPF 50+, and reapplication every two hours.

What is mineral sunscreen?

Mineral sunscreen is sunscreen whose active ingredients are zinc oxide, titanium dioxide, or both. Those actives absorb UV radiation and convert it to heat, the same way chemical filters do. In Australia they're TGA-regulated and can reach SPF 50+, same as any other sunscreen.

You'll see the same thing sold as physical sunscreen, zinc, or clear zinc. The "physical" label is a hangover from the old reflection idea, not a different product. Non-nano on a label means the zinc particles measure above 100 nanometres.

On the skin it can feel heavier than a chemical formula, and some leave a faint cast, though that has improved a lot. What you get for it is a filter that suits plenty of people whose skin reacts to organic ones. Our clear zinc SPF 50 is the mineral one we make.

If sunscreen has never given your skin trouble, there's no need to switch. If it has, mineral is worth a go.

Do mineral sunscreens reflect UV rays?

Mostly, no. Zinc oxide and titanium dioxide protect skin by absorbing UV and converting it to heat, the same way chemical filters do. A small amount of reflection and scattering happens at the surface, but absorption does the work.

A 2016 study in Photodermatology, Photoimmunology, and Photomedicine put a number on it. Reflection from zinc oxide and titanium dioxide measured 4 to 5 per cent across the UV range, less than SPF 2 worth of protection.

Australian work has since backed it up. In late 2025, chemists at UNSW Sydney measured zinc oxide and ten sunscreens in the lab, then read the ingredient lists of 143 products on the TGA register that declare only mineral actives. At least 48 of them, close to one in three, contained other UV-absorbing compounds as well.

We're chemist-operated, so we read the whole ingredient list rather than the actives alone. Mineral and chemical sunscreens feel different on the skin and suit different skin types. That's the part worth choosing on.

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.

Some Common Myths About Mineral Sunscreen

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

Mineral sunscreen is the natural option.

Actually

"Natural" isn't a regulated term on a sunscreen label. Zinc oxide is the active, but the rest of the tube is emollients, emulsifiers and preservatives, the same supporting cast as any other sunscreen. UNSW chemists also found close to one in three Australian sunscreens listing only mineral actives contained other UV-absorbing compounds. Read the ingredient list, not the word on the front.

Myth

Mineral sunscreen is reef friendly.

Actually

"Reef friendly" has no agreed scientific or legal definition in Australia, and mineral filters don't earn one. The closest actual rule is Hawaii's Bill S2571, which bans oxybenzone and octinoxate. Maxiblock formulas contain neither. Beyond that specific point, it's marketing language on any bottle.

Myth

Non-nano zinc is the safer choice.

Actually

Non-nano describes particle size rather than a safety rating. Under the AICIS definition, zinc counts as nanoscale if at least half its particles measure under 100 nanometres, whether they sit loose or clumped into larger clusters. Clumping doesn't take it out of the definition, because the definition already allows for it.

The EU requires nanoscale ingredients to be labelled as such. Australia has no equivalent rule. So on an Australian shelf, "non-nano" is a claim with no mandatory counterpart to check it against.

Still not sure which suits you?

Answer a few questions.

Has your skin ever reacted badly to sunscreen?

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

How would you describe your skin?