UV protection factor in sunscreen

SPF: This is the UVB protection factor, indicated by a number; a higher number is better. For rivers, the sea, and beaches, an SPF of 50 or higher is required. For hiking and skiing, an SPF of 30 or higher is necessary. For daily life, an SPF of 15 or higher is required.

PA: This is the UVA protection factor indicated by plus signs (+). A higher number is better. For rivers, oceans, and beaches, PA+++ or higher is required. For hiking and skiing, PA++ or higher is necessary. For daily life, PA+ or higher is required.