ISO 24442:2022

Overview

ISO 24442:2022 - Cosmetics - Sun protection test methods - In vivo determination of sunscreen UVA protection - specifies a standardized, in vivo method to determine the UVA Protection Factor (UVAPF) of topical sunscreen products. The method uses the persistent pigment darkening (PPD) endpoint to quantify protection in the UVA spectral range (320–400 nm). ISO 24442:2022 provides the technical basis for evaluating how well a product protects human skin from UVA-induced effects and supports product labelling and regulatory UVA classification.

Key topics and requirements

• Test principle: In vivo determination of UVA protection using the PPD response to controlled UVA exposure.
• Test subjects: Selection criteria, skin‑colour typing, age restrictions, ethics/consent, frequency of participation and minimum subject numbers are defined to ensure reproducible results.
• UV source and beam quality: Specifications for UV solar simulators, beam uniformity, spectral quality and total irradiance; annexes describe source definition and quality criteria.
• Measurement and monitoring: Use of spectroradiometry and radiometry to characterise and maintain UVA output during testing.
• Reference materials: Normative reference sunscreen formulations and recommended reference standards to validate test performance.
• Product application and exposure: Controlled application methods, site positioning, drying time, exposure progression and sub-site testing to ensure consistent dose delivery.
• Endpoint assessment: Procedures for PPD grading, timing of assessments, erythema handling, MPPDD determination, data rejection and test failure criteria.
• Calculations and statistics: Methods to calculate individual and product UVAPF, statistical criteria for validation and reporting requirements.
• Documentation: Required content for the test report and sample report forms provided in an informative annex.

Applications and who uses it

• Sunscreen manufacturers use ISO 24442:2022 to substantiate UVA performance claims and to design broad‑spectrum formulations.
• Independent testing laboratories implement the method for product certification, quality control and regulatory submissions.
• Regulatory bodies and standards organizations use the UVAPF data for product labelling, market surveillance and classification schemes.
• Dermatologists and researchers rely on standardized UVAPF results to compare product efficacy in clinical or epidemiological studies.
• Brand managers and marketers use validated UVA metrics to communicate balanced UVA/UVB protection to informed consumers.

Related standards

• ISO 24444 - Sun protection test methods - In vivo determination of SPF (related SPF methodology referenced and aligned with ISO 24442).
• Documents and methods from JCIA (origin of the PPD approach) are acknowledged in the Introduction and annexes.

Keywords: ISO 24442:2022, UVAPF, UVA protection factor, in vivo, persistent pigment darkening, PPD, sunscreen testing, sun protection test methods, UV solar simulator.