Sunscreen + Zinc Oxides

Your Cosmetic Chemist
1 day ago
4 min read

The growth of handmade beauty has sparked amazing curiosity and innovation. Watching people explore ingredients, ask questions, and build confidence in formulation is one of my favorite parts of this industry.

But there is one area where excitement has to pause and serious caution needs to step in.

Sun protection.

I see creators online sharing recipes for “natural,” “chemical-free,” or “non-toxic” UV products almost daily. And I’ll be honest — every time I come across one, it makes my stomach tighten a little.

Not because plant-derived materials are somehow inferior.Not because independent makers lack talent.

It’s because this category carries medical, legal, and ethical responsibility that goes far beyond typical skincare.

Why the Language Matters

Let’s clear up two phrases that appear constantly.

Chemical-free is scientifically impossible.Water is a chemical. Shea butter is a chemical. Zinc oxide is a chemical. Everything we use in formulation is made of chemicals.

Non-toxic is also complicated. In many regions it is considered regulated or misleading terminology because it can imply that approved, commercially available products are toxic or dangerous. Those products have gone through safety assessments, regulatory review, and mandated testing. Suggesting otherwise can cross into false advertising territory.

Using these buzzwords might sound appealing in marketing, but they create inaccurate comparisons and potential legal problems.

Why This Category Is Different

Ultraviolet filters are not about moisturization or skin feel. They are about preventing burns and reducing long-term damage.

When someone reads an SPF value, they assume it has been verified through standardized testing. They are trusting the number. If that trust is misplaced, the result is not just disappointment — it can be injury. Sunscreens are classified as drugs or quasi-drugs in most countries.

Training Isn’t the Same as Testing

Knowing how to build emulsions, create stable dispersions, and select appropriate raw materials is essential — but education does not replace formal validation.

I was trained as a cosmetic chemist and taught how to design compliant UV protection systems. And I still don’t manufacture them.

Why? Because once a prototype is made, it must be submitted for efficacy testing to confirm that it truly delivers the protection level it claims. That process is specialized, expensive, and time-consuming, often involving multiple rounds if the first submission fails.

Having the knowledge to formulate and having verified performance data are two very different things.

The Real Danger of DIY Claims

A balm containing minerals is not automatically protective.A visible white layer is not proof of coverage.Thicker is not necessarily better.

Protection depends on microscopic distribution and film integrity. Gaps cannot be seen without specialized equipment, and failures usually become obvious only after the skin has already been harmed.

The desire to make products that feel wholesome and safe is admirable. Yet responsible formulation also means recognizing when a category requires resources beyond a home lab.

And ultraviolet protection is one of those categories.

If you'd like, I can next explain what actually happens inside a testing facility, why prototypes often fail even when the math looks perfect, or how regulatory agencies evaluate claims.

There Are Great Natural Options Available

Choosing mineral protection from established, compliant brands is completely valid. Natural does not mean ineffective — it simply means professionally developed and tested.

UV Radiation Basics

Sunlight includes wavelengths that can harm the skin, typically between 290 and 400 nm.

Melanin offers some natural defense, so deeper skin tones often have a higher inherent resistance to burning, but no skin type is immune to damage.

Exposure risk changes depending on:

time of day (strongest mid-day)
altitude and season
reflective environments like snow or water
clothing coverage

Types of UV Filters

Organic (Chemical) Filters

These absorb radiation and transform it into heat.

Common examples include:

Oxybenzone
Octinoxate
Homosalate
Ethylhexyl salicylate

Each one protects a specific slice of the spectrum, so blends are usually necessary.

Inorganic (Mineral) Filters

These primarily scatter and reflect radiation, while also absorbing some.

Examples:

Zinc oxide
Titanium dioxide

Their effectiveness depends heavily on particle size and dispersion quality.

Zinc Oxides

When people begin exploring mineral protection, one of the first surprises is that the same INCI name can describe materials that behave very differently in a formula.

I was recently asked whether the grade used in a deodorant is the same as the one used in a sun product.

The honest answer is: yes… and no.

They may all be labeled zinc oxide, but particle size, surface treatment, and physical format dramatically change how they perform, how they disperse, and what they are suitable for.

Let’s look at the common variations you’ll see from MakingCosmetics and how they differ.