SPF 30, SPF 40, SPF 9052 – It seems like it keeps going up in number is it the higher the number, the better? Is it just a marketing thing? What’s going on here? >It’s a little bit of both I used to feel that 30 was high enough but now we’re talking 30 to 50 being high enough— >What’s the difference? >And the difference really is how long you can stay in the Sun without getting burnt because the SPF stands for Sun Protection Factor but in the old days it really stood for Sun Burn Protection Factor and it told us how much longer you could stay in the Sun without burning with the sunscreen on than when you didn’t have the sunscreen on now there are some extra tests that they do because they’re trying to protect you from the tanning rays because what happened back in the 70s is that we had the Sun Tan Lotion ‘s and they were SPF 4 to 8 maybe 15 and what was happening is that people were going out and they weren’t burning so that they could stay out in the Sun far longer than they could before— And without burning but being golden brown which they liked, but— yeah >And there is a but, the but is in the 80s we suddenly saw an epidemic of melanomas and if you looked at the curve showing the rise in the use of Sun Tan products in the 70s you could superimpose the rise in melanoma in the 80s so that’s when there was a whole thing of scare that sunscreens were actually causing melanoma but it really turns out it was a secondary unintended effect because now you were getting far more of the tanning rays you were not protected against that and now we learned that the tanning rays also play a large role.