Many sunscreens marketed to the public as SPF 50 or even SPF 50+ do not offer that level of protection from skin damage caused by ultraviolet rays that their labels claim, testing by the consumer advocacy group Choice has found.
Most people don’t understand how a Sun Protection Factor (SPF) is calculated, but know that a higher number is better, so a claim of SPF 50 or more is likely to sell more sunscreen.