Several popular beliefs about sunscreens are totally false. The most popular? "Believe you can not tan with sunscreen. A tan will be more gradual, certainly, but it is also more beautiful and more sustainable. You'll notice that your tan is much longer than a summer after returning from a trip to the South, "says Genevieve St-Cyr. Another myth concerns the SPF or sun protection factor. "Many people believe that an SPF 30 protection twice as much as an SPF 15. This is not the way it works. The screens with SPF 15 blocks 93% of UVB rays, while SPF 30 blocks 97% of UVB rays. An SPF 30 is not twice as effective as SPF 15, "says dermatologist. It is also wrong to believe that the more one pays the price, the better the sunscreen. "There is no need to pay dearly for sunscreens, since there was no link between price and quality. Often, you pay for the brand, while it should not be a criterion for selection, "said Dr. Tremblay. Finally, it says that no study has demonstrated so far that there would be risks to be used on a regular and long term sunscreens. In any case, most dermatologists agree that if a possible risk were to be demonstrated, the latter still remain less than what we face going in the sun without protection.