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Transitioning from Chemical to Mineral Sunscreens: What Formulators Need to Consider

  • Geoff Acton
  • 10 hours ago
  • 5 min read


Introduction


Advance ZincTek manufactures pharmaceutical-grade zinc oxide and ZinClear® dispersions under GMP-certified conditions in Queensland, supplying formulators moving from organic UV filter systems toward non-nano zinc oxide. That shift is now underway across the industry, driven by regulatory tightening on established organic filters and by the technical case for zinc oxide as a single, photostable broad-spectrum active. The sections below set out why the transition is happening, what it demands of a formulation, and what to look for when sourcing the zinc oxide behind it.



Executive Summary


  • Regulatory pressure is driving the shift: zinc oxide holds FDA GRASE Category I status while organic filters remain in Category III, and the EU and Australia's TGA have both tightened limits on established organic filters since 2022.

  • Formulation advantages extend beyond compliance: zinc oxide delivers single-active broad-spectrum coverage, does not require photostabilization, and white cast is solved through particle microstructure and carrier index-matching rather than nano particle size.

  • Performance at the sourcing stage is determined by BET surface area grade, purity, coated versus uncoated status and carrier system, not simply the percentage of zinc oxide in the formula.

  • ZinClear® XP solves this for formulators through clean high-shear dispersion, a pre-dispersed range across five oil-phase carriers, and IM-grade particle engineering for transparency, with dispersion quality and emulsion stability built in from formulation inception.

  • The practical route for formulators is a consistent, GMP-manufactured, non-nano uncoated zinc oxide supply: ZinClear® XP is offered across five BET grades from 15 to 44 square metres per gram and has achieved SPF 50 in vivo at 25 wt% ZnO, tested to ISO 24444.



Regulatory Pressure Is Driving the Shift


Regulatory pressure on organic UV filters is reshaping sunscreen formulation strategy. In the United States, zinc oxide remains one of only two actives holding GRASE Category I status under FDA Monograph M020, while the organic filter class continues to sit in Category III pending further safety data. The FDA's own maximal-use trials found systemic plasma concentrations of organic filters far exceeding the agency's assessment threshold, with oxybenzone reaching levels above 258 ng/mL in a companion trial testing six actives across four formulation types (Matta et al., 2020). Zinc oxide, by contrast, does not penetrate the stratum corneum at non-nano particle sizes.


The European Union has moved in the same direction. Since 2022, homosalate has been restricted to face-only applications at a maximum of 7.34%, with full enforcement from July 2025, and octocrylene and oxybenzone limits have tightened under successive SCCS opinions. Australia's TGA opened a 2025 consultation on additional controls for homosalate, oxybenzone and the degradant benzophenone, driven by exposure modelling that reflects the country's high per-capita sunscreen use. Non-nano zinc oxide sits outside every one of these restrictions and carries none of the associated reformulation risk.



Formulation Advantages Beyond Compliance


The case for zinc oxide is not purely regulatory. As a wide-bandgap semiconductor, zinc oxide absorbs UV photons across the 290 to 400 nanometre range and converts that energy to heat, while its particulate structure scatters longer UVA wavelengths. This dual mechanism delivers full broad-spectrum coverage from a single active, eliminating the multi-filter cocktails and photostabilizer requirements that organic systems depend on. Avobenzone, the most common organic UVA filter, degrades by roughly half after one hour of UV exposure unless stabilized with a co-filter such as octocrylene. Zinc oxide requires no such stabilization and does not degrade under UV exposure.


The historical objection to zinc oxide, white cast, is a solvable formulation problem rather than an inherent limitation of the active. Transparency is achieved by controlling particle microstructure and index-matching the particle to the carrier oil, reducing the refractive index differential that causes visible-light back-scattering. This route to optical clarity does not require particle-size reduction into the nano range. Non-nano uncoated zinc oxide dispersions built on this principle can achieve high visible-light transmission while remaining well above the 100 nanometre nano threshold, preserving the labeling advantages that non-nano status confers in the EU and other markets.



What Determines Performance at the Sourcing Stage


Reformulating around zinc oxide shifts the technical burden to raw material selection. BET surface area is the primary driver of scattering efficiency per gram: higher BET grades suit high-SPF and baby-care formats, lower BET grades suit lightweight daily wear, and batch-to-batch consistency in BET surface area is what makes SPF performance repeatable across production runs. Purity minimizes soluble-ion contamination that drives irritation and emulsion instability. Uncoated material keeps the INCI declaration to zinc oxide alone, supporting clean-beauty and preservative-free positioning, since zinc oxide is inherently antimicrobial.


Zinc oxide is slightly soluble below pH 7.5, and free zinc ions react with anionic thickeners such as carbomers, collapsing emulsion viscosity. Formulating above pH 7.5, avoiding carbomer systems and selecting nonionic or cationic emulsifiers preserves stability. Pre-dispersing zinc oxide in a compatible oil phase before emulsification prevents agglomeration, which directly affects the UV attenuation curve. Ready-to-use dispersions in carriers such as caprylic/capric triglyceride, C12-15 alkyl benzoate or coco-caprylate/caprate remove the need for in-house high-shear milling while allowing the carrier to be matched to the target skin feel and certification requirement.



How ZinClear® XP Solves This for Formulators


ZinClear® XP builds SPF reliability in at the design stage rather than fixing it after the fact. The powder disperses cleanly under standard high-shear processing, and the pre-dispersed range (in C12-15 alkyl benzoate, caprylic/capric triglyceride, coco-caprylate/caprate, coconut oil or sunflower oil) removes agglomeration and settling risk entirely, with IM grades adding a porous, index-matched particle structure for transparency.


It's manufactured by Advance ZincTek as a pharmaceutical-grade, uncoated, non-nano zinc oxide under GMP conditions in Queensland, the only single active giving broad-spectrum UVA/UVB coverage. Made via Antaria's mechano-chemical process across five BET grades (15–44 m²/g), it delivers the batch-to-batch consistency needed for repeatable SPF, confirmed at SPF 50 in vivo (ISO 24444) using just 25% ZnO.



Conclusion


The transition from chemical to mineral systems is being driven simultaneously by regulatory tightening, documented environmental toxicity and dermatological preference for reactive and pediatric skin. Mineral formats held over half of category revenue in 2024, and zinc oxide is the dominant active within that segment. For formulators evaluating this shift, the specification that matters is not simply the percentage of zinc oxide in a formula, but the particle-size distribution, BET surface area grade, purity and carrier system behind it. ZinClear® XP, available as both non-nano uncoated powder and pre-dispersed formats across five BET grades, addresses the SPF, transparency and stability variables together at formulation inception rather than trading one against another downstream.



References


Matta, M. K., Zusterzeel, R., Pilli, N. R., Patel, V., Volpe, D. A., Florian, J., Oh, L., Bashaw, E., Zineh, I., Sanabria, C., Kemp, S., Godfrey, A., Adah, S., Coelho, S., Wang, J., Furlong, L.-A., Ganley, C., Michele, T., & Strauss, D. G. (2019). Effect of sunscreen application under maximal use conditions on plasma concentration of sunscreen active ingredients: A randomized clinical trial. JAMA, 321(21), 2082–2091. https://doi.org/10.1001/jama.2019.5586

U.S. Food and Drug Administration. (2021). Proposed order OTC000008: Amending over-the-counter monograph M020, Sunscreen drug products for over-the-counter human use.

European Commission. (2022a). Commission Regulation (EU) 2022/2195 of 10 November 2022 amending Regulation (EC) No 1223/2009 as regards the use of butylated hydroxytoluene, acid yellow 3, homosalate and HAA299 in cosmetic products. Official Journal of the European Union.

European Commission. (2022b). Commission Regulation (EU) 2022/1176 of 7 July 2022 amending Regulation (EC) No 1223/2009 as regards the use of certain UV filters (benzophenone-3, octocrylene) in cosmetic products. Official Journal of the European Union.

Matta, M. K., Florian, J., Zusterzeel, R., Pilli, N. R., Patel, V., Volpe, D. A., Yang, Y., Oh, L., Bashaw, E., Zineh, I., Sanabria, C., Kemp, S., Godfrey, A., Adah, S., Coelho, S., Wang, J., Furlong, L.-A., Ganley, C., Michele, T., & Strauss, D. G. (2020). Effect of sunscreen application on plasma concentration of sunscreen active ingredients: A randomized clinical trial. JAMA, 323(3), 256–267. https://doi.org/10.1001/jama.2019.20747

Therapeutic Goods Administration. (2025). TGA to consult on additional controls for some sunscreen ingredients [Media release]. https://www.tga.gov.au/news/media-releases/tga-consult-additional-controls-some-sunscreen-ingredients

Cole, C., Shyr, T., & Ou-Yang, H. (2016). Metal oxide sunscreens protect skin by absorption, not by reflection or scattering. Photodermatology, Photoimmunology & Photomedicine, 32(1), 5–10. https://doi.org/10.1111/phpp.12214

Grand View Research. (2025). Mineral sunscreen market size & share report, 2025–2030. https://www.grandviewresearch.com/industry-analysis/mineral-sunscreen-market-report

 
 
 

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