What does SPF 15 mean on lip balm?

SPF 15 on lip balm indicates that the product provides a level of protection against UVB rays, which are primarily responsible for sunburn and can contribute to skin cancer. Specifically, SPF 15 means that it can theoretically allow you to stay in the sun 15 times longer without burning compared to not using any protection. However, it's important to reapply lip balm regularly, especially after eating, drinking, or swimming, to maintain its effectiveness.