Functional & Processing FAQ

Three quick checks, in increasing order of effort.

First, the water float test: a treated powder floats on water and an untreated one wets and sinks. It is crude but it tells you immediately whether the surface is hydrophobic. Second, viscosity: at the same loading in the same oil, a treated powder gives a lower viscosity. Third, the instrumental route — TGA or elemental analysis to quantify the coating weight, which is what you use if you need a number for a specification.

For incoming QC, the float test plus a viscosity check catches almost everything that matters.

As a rough starting point, 5–10% combined inorganic solids gets you into the moderate-SPF range, and 15–25% is where mineral-only high-SPF formulas live — but the number that matters is measured in your own base, not calculated.

SPF depends on the film thickness, the dispersion quality, the presence of other filters and the base itself. Two formulas with identical filter loading can differ by several SPF points because of dispersion alone. That is why the pre-dispersion route often outperforms a powder route at the same nominal loading.

Test in vivo for the claim, and use in vitro for development iterations. Do not specify an SPF from a loading table.

This page is the catch-all for materials that do not sit cleanly in one of the other product families — specialty fillers, materials in development, and combinations that are made to order.

If you cannot find what you need in the twelve categories, describe the function rather than the material: what it has to do in the formula, what system it goes into, and what the constraints are on cost or regulatory status. That usually gets to a candidate faster than searching by product name.

For anything not listed, the answer starts with a conversation rather than a datasheet.

Yes, in the sense that the treatment agent becomes part of the ingredient declaration and must itself be permitted.

A treated powder is not the same regulatory object as the untreated one: the coating is an ingredient, so it appears on the INCI list and it has to be permitted for the product category in the destination market. Some treatment agents are permitted broadly; others have market-specific conditions.

We supply the INCI breakdown for each treated grade. If your regulatory team is checking a market's permitted list, give them the treatment agent as well as the base powder — that is where the question usually arises.

Yes — it is the main lever you have over the photocatalytic activity of the particle.

TiO2 and ZnO generate reactive species at the surface when they absorb UV, and those species attack the surrounding formula: fragrances fade, colours shift, emollients oxidise. An alumina or silica coating, or a silane treatment, passivates the surface and suppresses that activity. It also reduces the interaction between the mineral filter and organic filters in the same formula, which is where a lot of the instability in mixed systems comes from.

All our sunscreen grades carry a coating for this reason. If you are formulating with organic filters alongside, the coated grades are the safer choice.

Usually not — start at the same loading and adjust on the result.

The treatment is a small weight percentage on the surface, so the delivered pigment or powder content per kilo is essentially unchanged. What changes is the viscosity: a treated powder typically gives a lower viscosity at the same loading, which some formulators use to raise the solids content rather than to keep the loading constant.

In a pressed powder, the treated grade usually needs slightly less binder for the same press strength, because the lubricious surface packs better. Again, start at the same level and adjust.

Smaller particle size, better dispersion, and if necessary a lower loading with an organic filter carrying the rest of the SPF.

White cast has two causes. Undispersed agglomerates scatter visible light strongly and look like a chalky film; and larger particles scatter visible light by design. So the first fix is dispersion — a pre-dispersion at 15–30 nm usually removes most of the cast without changing the loading. The second is size: moving from 80 nm to 15 nm reduces the visible scatter substantially.

If the cast persists at the SPF you need, the honest answer is that a mineral-only high-SPF product will have some cast on deep skin tones, and the formulation route is to blend with an organic filter rather than to keep reducing the particle size, which costs you UV efficiency.

It depends on the powder, but the treated grades are what make high loadings possible in silicone-continuous systems.

In a W/Si foundation, treated TiO2 and treated iron oxides commonly run at 8–15% combined with the silicone phase, and treated fillers at 5–15%. Untreated powders at those levels would raise the viscosity past the point where the emulsion can be processed.

That is the whole commercial case for treatment in this system: it is not an improvement in feel, it is what makes the formulation possible at all.

We provide the material documentation: COA, TDS, SDS, and the nano-specific statements a market may require. The finished-product testing — SPF, UVA-PF, critical wavelength, water resistance — is done on your formula, not on the raw material.

What we can support with is application data: dispersion guidance, recommended starting loadings, and the coating information you need for your safety assessment. For an in vitro SPF iteration we can tell you what has worked in comparable systems, but the number has to come from your own test.

If you need a specific market's nano notification supported, tell us the market and the product category at enquiry — the document set differs and it is better to assemble it before the launch date than after.

Yes — the hydrophilic treatment exists for water-based and O/W systems where you want improved dispersion without making the surface hydrophobic.

It is the counterpart to the lipophilic treatments: instead of repelling water, it makes the surface compatible with the aqueous phase, which improves dispersion in a water-based slurry or a gel and reduces the settling that untreated fines show in water.

Use it when your continuous phase is water and you have a dispersion problem. Do not use it if you need water resistance — it works in the opposite direction.

MOQ is 1 kg for a powder sample and 5 kg for a pre-dispersion sample; production quantities start at 25 kg. Lead time is 7–15 working days for stock grades, longer for a custom carrier.

Because nano materials attract more documentation, allow extra time before a first shipment into a new market. Samples ship with COA, TDS and SDS, and with the particle size data you will need for the nano assessment.

Store sealed at 15–30 °C. Pre-dispersions should be rolled before use, as the solids settle.

25 kg for a stock treated grade; a treatment applied to a grade we do not normally carry is 100–200 kg, because the treatment line has to be set up and cleaned.

Lead time is 7–15 working days for stock, longer for a custom combination of base grade and treatment. Samples at 1 kg are available for any stock combination.

If you are evaluating a treatment, ask for the treated and untreated version of the same base grade. Comparing them against each other in your own base is the only way to see what the treatment is actually doing.