Using a mineral sunscreen that is labeled Broad Spectrum is critical to protecting your skin from BOTH forms of UV light that can harm your skin, and that can lead to skin cancer. An SPF sunscreen that is NOT BROAD SPECTRUM only protects you from UVB rays, and leaves you exposed to the harmful effects of UVA Rays (such as premature aging, wrinkles, and dark spots). A zinc based mineral sunscreen provides Broad Spectrum UVA/UVB protection.