Sunscreen is one of the most heavily regulated categories in cosmetics. How you test SPF, what number you can print on the label, and which UV filters you may use all depend on the market. This article covers the differences between chemical and mineral filters, the ongoing debate over SPF testing methods, and the regulatory caps on SPF claims across the EU, US, China and Japan.

Chemical vs. Mineral UV Filters: Formulation Implications

UV filters fall into two broad families:

  • Chemical (organic) filters — avobenzone, octinoxate, octocrylene, homosalate, Tinosorb S/M, Uvinul A Plus. They absorb UV radiation and convert it to heat. Advantages: lightweight texture, easy to formulate into daily-wear products. Disadvantages: some (oxybenzone, octinoxate) face regulatory restrictions or consumer backlash in certain markets due to reef-safety concerns.
  • Mineral (inorganic) filters — zinc oxide and titanium dioxide. They scatter and reflect UV radiation. Advantages: broad-spectrum protection, photostable, reef-safe reputation. Disadvantages: white cast on darker skin tones, thicker texture, harder to formulate at high SPF levels without nanoparticle technology.

UV spectrophotometer measuring SPF in a cosmetics lab

SPF Testing: In Vivo vs. In Vitro

The gold standard for SPF testing is the ISO 24444 in vivo method: apply the product to human subjects, expose to a solar simulator, and measure the minimal erythema dose (MED). This method is accepted in the EU, US, Japan and China for label claims.

In vitro methods (ISO 24443) measure UV transmittance through a substrate coated with the product. They are faster and cheaper, and the EU allows in vitro data for UVA claims and for products that cannot be tested in vivo (e.g., products containing ingredients that make ethical testing difficult). However, in vitro SPF values do not replace in vivo data for the primary SPF label claim in most jurisdictions.

The practical implication: a brand that wants to claim SPF 30 must invest in in vivo testing. In vitro screening is useful during formulation development to identify promising candidates, but the final label claim requires the ISO 24444 study.

SPF Claim Caps by Market

  • EU — SPF claims are capped at 50+. Labels may use categories (Low 6–10, Medium 15–25, High 30–50, Very High 50+). Claiming "SPF 100" or "total protection" is prohibited.
  • US — FDA caps SPF claims at 50+ for labels (proposed rule, 2011; still pending finalization). Products tested above SPF 50 may only claim "SPF 50+" on packaging.
  • China — NMPA caps SPF claims at 50+ (GB/T 18830). Special-use cosmetics registration (特殊用途化妆品) is required for sunscreen products, which adds 6–12 months to the launch timeline.
  • Japan — SPF claims capped at 50+ under JCIA guidelines. Japan uses PA+ system for UVA protection (PA+ to PA++++).

Broad-Spectrum: The UVA Requirement

In the US, a sunscreen can only claim "broad spectrum" if it passes the FDA critical wavelength test (critical wavelength ≥ 370 nm). In the EU, the UVA protection factor must be at least one-third of the SPF value (e.g., SPF 30 requires UVA-PF ≥ 10). Japan and Korea use the PA+ system. A product that claims SPF but lacks adequate UVA protection faces regulatory action and consumer credibility issues.

What Brand Owners Should Know Before Commissioning a Sunscreen

  1. Decide the target markets first — UV filter availability and SPF caps vary. A formula optimized for the EU (Tinosorb-based) may not be legal in the US (where Tinosorb S/M are not FDA-approved).
  2. Budget for in vivo SPF testing — ISO 24444 studies cost $15K–$30K per product depending on the lab and sample size. This is not optional for a label claim.
  3. Plan for special-use registration in China — sunscreen is classified as special-use, requiring a separate registration process that takes 6–12 months beyond standard cosmetics filing.
  4. Check UV filter restrictions — Hawaii, Palau and Thailand have banned oxybenzone and octinoxate in reef areas. If you sell in Asia-Pacific beach markets, formulate without these filters.

Related Reading

SPF claims are where cosmetic regulation meets consumer trust most directly — get it right, and your brand earns credibility; get it wrong, and the consequences are both legal and reputational. CHONGSHENG FUTURE develops sunscreen formulations tested to ISO 24444 and aligned with EU, US, China and Japan claim limits. Contact us to discuss your sun-care project.