Abstract
PROBLEM: What are the health effects of insufficient UV protection in sunscreen products? What methods are available for determining the Sun Protection Factor (SPF), and what are their advantages and disadvantages? DESCRIPTION OF THE PROBLEM: Skin cancer is one of the most common types of cancer in the Netherlands. Sunscreen products are used to protect the skin against UV radiation. The SPF is the means by which manufactures indicate the level of protection the product offers against UV radiation. However, with the current testing methods for sunscreen products SPF is only determined as the amount of UV radiation needed to turn the skin red, caused by UVB radiation with and without sunscreen. However, skin cancer is also caused by UVA radiation. Therefore it is important that sunscreen protects against both UVA and UVB radiation. RESULTS: In vivo reference methods measure UVA and UVB protection based on observation of an acute effect in test subjects: the erythemal response to UVB radiation and the tanning of the skin by UVA radiation. In vitro methods are also available. The advantage of these methods is that they enable the entire spectrum of UV radiation to be quantitatively measured. However, these in vitro results are corrected to correlate more with the results obtained using the in vivo reference methods. LESSONS: The in vivo reference methods are not based on the critical effect of skin cancer. The in vitro method is currently corrected on the basis of the results obtained using the in vivo reference methods. Many factors can affect the UV protection of a sunscreen product or the measured SPF. Using a sunscreen product with an actual SPF lower than the claimed SPF leaves the consumer more exposed to UV radiation. Any additional exposure to UV radiation can in the long term increase the risk of skin cancer. KEY MESSAGES: • Implement one factor to indicate the protection against UVA- and UVB-radiation and develop a suitable in vitro method. • The in vivo reference methods are not based on the critical effect of skin cancer TOPIC: Sun Protection Factor (SPF), UV-radiation, Reference method.