A recent investigation by CBC Marketplace reveals discrepancies between the SPF numbers printed on sunscreen bottles and the actual protection they provide. This discrepancy could lead consumers to have a false sense of security when relying on sunscreen for sun protection.
Marketplace conducted tests on a popular SPF 50 sunscreen at five accredited labs in Canada and the U.S. The results varied widely, with each lab reporting a different SPF rating for the product: 34, 50, 60, 44, and 15.
The focus of the investigation was on the SPF testing process rather than the specific product, so CBC did not disclose the product’s name. Similar studies have highlighted the common variability in sunscreen testing accuracy.
Experts, including Brian Diffey, a photobiology professor, expressed concern over the inconsistent results and questioned the reliability of SPF ratings. Health Canada, responsible for regulating sunscreen in Canada, did not comment on the Marketplace investigation findings.
SPF, which stands for sun protection factor, indicates protection against UVB rays only, not UVA rays. The higher the SPF number, the greater the protection against UVB rays. For example, SPF 50, 30, and 15 absorb or reflect approximately 98%, 97%, and 93% of UVB rays, respectively.
Dermatologists emphasize the importance of applying sunscreen generously for effective protection. While SPF testing traditionally involves human volunteers, newer methods are being explored to improve accuracy. However, current testing methods still have limitations, leading to variability in SPF ratings.
Despite the challenges in SPF testing, experts agree that sunscreen remains essential for sun protection. Consumers are advised to use sunscreen along with other sun-safe practices like seeking shade and avoiding peak sun hours to protect their skin.
The sunscreen industry has faced instances of fraud, underscoring the need for more transparency and oversight. Consumers are encouraged to be vigilant and choose sunscreen products wisely. Experts recommend focusing on consistent and generous application rather than fixating on specific SPF numbers for effective sun protection.
