A recent investigation by CBC Marketplace has revealed discrepancies between the SPF numbers printed on sunscreen bottles and the actual protection they provide. This disparity could give users 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 the labs reporting SPF values of 34, 50, 60, 44, and 15. This inconsistency sheds light on the lack of oversight in the testing process.
Experts like Brian Diffey, a photobiology professor, expressed concern over the findings, questioning the accuracy of SPF ratings. Health Canada, responsible for regulating sunscreen in Canada, did not comment on the investigation results.
SPF, or sun protection factor, indicates protection against UVB rays, while “broad spectrum” sunscreen protects against both UVA and UVB rays. The higher the SPF number, the greater the protection against UVB rays, with SPF 50, 30, and 15 absorbing or reflecting approximately 98%, 97%, and 93% of UVB rays, respectively.
Testing for SPF involves exposing volunteers’ skin to simulated sunlight and evaluating the level of redness to calculate the SPF value. However, consumer behavior, skin absorption, and application techniques can affect the actual protection provided by sunscreen.
Despite testing variability and past fraud in the sunscreen industry, experts emphasize the importance of sunscreen use as a crucial defense against skin damage. They advise consumers to apply sunscreen generously, seek shade, cover up, and avoid peak sun hours for comprehensive sun protection.
While calls for improved transparency and retesting of sunscreens have been made, the focus remains on promoting consistent and effective sunscreen use to safeguard skin health.