You do have to be careful in how you remove them, or you will cause awful damage. As for the UV etc, I checked this out pretty thoroughly before purchasing and, although there are a lot of scare stories out there, there are also a lot of scientific data that points out that the amount of time/strength of the light from the LED lights (used in RCM) is so minimal (equivalent to a few minutes of strong sunlight), that any increased risk is negligible (if present at all) and that since people don't even see an increase in light-related things like freckles etc, it's a sign that things are not so bad. There is a little more concern about the older non-LED lamps, but even then not that much. That being said, because I have very fair skin, and I'm a belt-and-braces type of person, I always apply my usual sunscreen (Ultrasun SPF 50) before applying the RCM, which should provide ample protection.