Expand A sunscreen can be labeled “Broad Spectrum” if it provides UV protection across both the UVB and UVA wavelength ranges. UV radiation in sunlight is divided into several ranges depending on the wavelength. UVB radiation covers the wavelength range between 290 and 320 nanometers, and UVA radiation is between 320 and 400 nanometers. Sunburn is primarily caused by UVB. UVB and UVA can cause sunburn, skin cancer and premature skin aging. According to FDA, only products labeled with “Broad Spectrum” and SPF 15 or (higher) have been shown, if used as directed with other sun protection measures, to provide these benefits.