A. I'm not going to tell you how many years I've been sticking my freshly manicured fingers into that drying machine—and it never even occurred to me to inquire what the blue light is. St. Elmo's fire? A deadly gamma ray? Which reminds me how much I take for granted my poor paper-cut hands. If I were smart enough to follow the advice of a leading dermatologist—for example, Loretta Ciraldo, MD, clinical professor of dermatology at the University of Miami and author of 6 Weeks to Sensational Skin—I'd apply water-resistant sunscreen on my hands, right down to the fingertips, every day. And if I were even more risk averse than I am, I'd also reapply it about an hour before I had a manicure. But I probably won't, because the amount of UVA light—10 watts, compared with about 2,400 watts in a tanning bed—emitted by the polish dryers isn't strong enough to merit concern, Ciraldo says. Does that light do anything, though? Only if you have nail enhancements like acrylics or gel wraps, in which case it can accelerate drying time, says Suzi Weiss-Fischmann, executive vice president of OPI. (The typical top coat applied to your natural nails protects them against UVA light, which discolors pigmented polish.)
Bottom line: That light isn't strong enough to do any damage.