The SPF Debate: Mineral or Chemical?

There's something rather lovely about seeing sunscreen become a talking point of an Irish summer.

For years, SPF was something many just packed into a beach bag before a holiday abroad. We'd buy it at the airport, use it diligently for a week in the sun, then quietly tuck it away again until the following summer.

Thankfully, this year has felt different.

With Ireland enjoying an extraordinary spell of warm weather, sunscreen has become part of our morning routine rather than our holiday checklist. And while that's undoubtedly a very good thing, and is exactly how it should be, it has also highlighted just how confusing the world of SPF can feel.

Mineral or chemical? SPF 30 or 50? Does it matter? Which one is better?

They're questions we hear all the time, and the truth is that the answers are refreshingly straightforward.

Why sunscreen matters, even in Ireland

It's easy to think about sunscreen only when the sun is shining, but the skin doesn't see the weather in quite the same way that we do.

The UVB rays that cause sunburn become stronger during sunny weather, but UVA rays, which penetrate deeper into the skin, are present in every day throughout the year. They are a major contributor to premature skin ageing, pigmentation and collagen breakdown, and can pass through cloud and even glass. That's why dermatologists recommend wearing a broad-spectrum, high SPF every day, not just on holiday.

Many of us think about sunscreen in beauty terms, for preventing wrinkles or pigmentation, but its most important role is helping to protect the skin from the DNA damage caused by ultraviolet radiation, reducing the risk of skin cancer over time. It's one of the simplest daily habits we can adopt to protect our skin, both now and in the years ahead.

Think of sunscreen less as a summer product and more as the final step in your morning skincare routine. Every morning.

Mineral and chemical SPF: What's the difference?

This is where it can often become more complicated than it needs to be.

Both mineral and chemical sunscreens are highly effective at protecting your skin. They simply go about it in different ways.

Mineral sunscreen

Mineral sunscreens use filters such as zinc oxide and titanium dioxide. These mineral filters sit on the skin's surface, where they absorb, reflect and scatter UV radiation before it can damage the skin. This is the traditional 'sun block' kind of product, basically blocking the sun's damaging rays.

They're often the first choice for sensitive skin, reactive skin, rosacea or skin that's recovering after professional treatments.

Modern mineral formulas have come a long way from the thick, chalky creams many of us remember. Today's versions are lighter, more elegant, more invisible and frankly, far more enjoyable to wear than they once were.

They are particularly well-suited to those who prefer a minimalist skincare routine or want something exceptionally gentle. They can now be mixed with pigment in a much better way than before now, so they can offer a superb summer base for evening our skin tone. 

That said, the amount you use matters, so sometimes the pigmented products and skin tints can feel heavy in terms of coverage if you use the mandated 'two fingers' amount required to effectively protect your face. So, that choice is up to you. The non-negotiable is the amount you use - tiny amounts offer sheer protection, and sheer protection doesn't protect -  so you see the dilemma! In my view, layers are better - layer the visible (tints) on top of the invisible (SPF), and you're winning.

Chemical sunscreen

Chemical sunscreens use a mix of UV filters that absorb ultraviolet radiation and convert that energy into a tiny amount of heat, releasing it harmlessly before it can damage the skin.

The thing with these is that they must be absorbed into the skin to work, and can take 20 minutes to come into effect, presenting two scenarios some people don't like: a) that they are in the blood, and b) they take time when people want immediate protection. 

The biggest advantage is often cosmetic elegance. Many formulas disappear effortlessly into the skin, layer beautifully beneath makeup and feel almost weightless, making them incredibly easy to wear every day. They do degrade every two hours though, so they must be reapplied with diligence.

So, which is better?

Honestly? Neither.

For years, the beauty industry has framed mineral versus chemical sunscreen as though we need to choose sides, when in reality, they're simply different technologies designed to achieve the same goal.

The better question isn't which formula is superior. It's which one feels so comfortable on your skin that applying it becomes second nature. Consistency will always outperform perfection - and many dermatologists say that the best SPF is the one you will actually wear every day.

A quick note on SPF numbers

Another common misconception is that SPF 50 offers dramatically more protection than SPF 30.

In reality, the difference is smaller than many people imagine. SPF 30 filters around 97% of UVB rays, while SPF 50 filters around 98%.

The bigger difference comes in real life, where most of us apply far less sunscreen than is used during laboratory testing. That's one of the reasons dermatologists often recommend choosing SPF 50 for everyday use, particularly if you're spending time outdoors.

And the amount to use? For your face and neck alone, aim for approximately two finger lengths of product. If you're spending extended periods outside, reapply every two hours, and sooner after swimming, sweating or towel drying. 

So that's a lot of re-applying in a heatwave. Don't think you're the bees' knees because you slapped on factor 50 at 7 am, because if you're sitting in the park for lunch with no reapplication at 1 pm, you're burning!

The skincare product that works the hardest

The beauty world is wonderfully exciting. New ingredients arrive every year, promising brighter skin, smoother texture and fewer fine lines, but if there is one product that consistently earns its place in every routine, for every reason, it's sunscreen.

Retinoids, peptides, antioxidants and growth factors all have their place, but protecting the skin from ultraviolet damage remains one of the most effective things you can do to support healthy, resilient, nice-looking skin over the years.

It isn't the most glamorous product in your bathroom cabinet, it may not be the most exciting, and it certainly doesn't have to be the most expensive - it just needs to be there, and it needs to be replenished the most often.

Our recommendation

At The Skin Studio, we're building a carefully considered collection rather than filling virtual shelves for the sake of sales volume. We'll be happy to offer a very small, but very strong selection of products that we can stand over.

That means every product has to earn its place and our virtual shelves will fill slowly as we test everything.

My current SPF recommendation is ODA Sunscreen Face Cream SPF 30, a lightweight broad-spectrum sunscreen that protects against both UVA and UVB rays while feeling beautifully comfortable on the skin. Enriched with Panthenol and Hyaluronic Acid, it sits lightly beneath makeup, leaves no heavy or greasy residue and has the kind of elegant texture that makes daily application feel really nice. I've been using it all summer and am hooked.

We'll continue to expand our sunscreen offering as our edit grows, but we're firm believers that you don't need twenty options. You simply need one you'll genuinely enjoy and use every day.