Global Perspectives on Regional Sun Protection Factor (SPF) Requirements: Scientific and Regulatory Insights

Ultraviolet (UV) radiation is a well-established environmental factor contributing to acute and chronic skin damage, including erythema, photoaging, pigmentary disorders, and skin cancer. Sunscreens represent a cornerstone of photoprotection strategies, with sun protection factor (SPF) serving as the primary measure of protection against UVB-induced erythema. However, UV exposure varies considerably across geographic regions due to differences in latitude, climate, altitude, and lifestyle, necessitating region-specific SPF recommendations. In parallel, sunscreen regulation and SPF claim substantiation differ across global jurisdictions, influencing product development, labeling, and consumer communication. This scientific communication reviews the biological basis of UV-induced skin damage, the rationale for region-wise SPF selection, and the regulatory frameworks governing sunscreen efficacy and claims across major global authorities, including India (Bureau of Indian Standards (BIS)), the European Union (EU; European Cosmetic, Toiletry and Perfumery Association (COLIPA)), the United States (Food and Drug Administration (FDA)), Australia (Therapeutic Goods Administration (TGA)), Canada (Health Canada), and Japan (Ministry of Health, Labour and Welfare (MHLW)/Japan Cosmetic Industry Association (JCIA)). While regulatory approaches differ in classification, UVA assessment methodologies, and labeling systems, there is a shared scientific consensus on the importance of validated SPF testing, broad-spectrum protection, and responsible communication. Harmonization through international testing standards has improved comparability of sunscreen efficacy, although regulatory diversity continues to pose challenges for global implementation. Integrating scientific evidence with existing region-specific regulatory requirements is essential for effective photoprotection, informed sunscreen use, and improved public health outcomes.