What is an SPF?

All sunscreens are labelled with a sun protection factor (SPF) number. This relates to the amount of time it takes for your skin to burn without any protection and how long it would take if you used the appropriate amount of sunscreen. An SPF is the ratio between the amount of UV which will cause sunburn in sunscreen protected skin, compared to that in unprotected skin. Sunscreens should not be used to extend the amount of time you would usually spend in the sun. Sunscreens should be used with other forms of sun protection, such as shade, hats and clothing, to protect you as much as possible.