When a watchdog group reviewed the products, they found that one out of seven portrayed SPF ratings above 50, which experts feel gives users a wrong sense of protection. This could also be inspiring them to stay in the sun for longer. Though consumers may think that SPF 100 is doubly effective as compared to SPF 50, the difference between the two is actually negligible.
"The high SPF numbers are just a gimmick," says Marianne Berwick, professor of epidemiology at the University of New Mexico. "Most people really don't need more than an SPF 30 and they should reapply it every couple of hours."
Dermatologists caution that sunscreen must always be used while going out in the sun, but that alone is not enough. Adequate protection with hats, shade and clothing must be taken to enable protection against ultraviolet radiation.