But if you read carefully, you will discover there are NO standard tests for UVB blockage so makers can make any claims they desire irregardless of scientific facts.
Perhaps YOU need to start reading carefully. These drugs must be passed by the FDA, which I assure you does look at scientific studies and facts.
You're confusing sunburn protection with UV protection. It's the UV protection that fades after a hour with chemical sunscreens.
The sunburn comes from the ultraviolet radiation. Light in the visible spectrum does not cause burns, unless you are talking about lasers or a really hot light bulb...
