UV " ultraviolet" lighting is almost obsolete at this point for gel manicures. In comparison, LED lights take anywhere from 5 to 45 seconds to harden polish whereas the UV lights took 2-3 minutes per hand or even in some cases, 2-3 fingers at a time! The curing process takes at least 30 seconds (nothing compared to time spent waiting for nails to dry the old-fashioned way). In 2014, a small study found that the UV radiation emitted from different gel lamps varied greatly. This study also found that it would take just 12 visits to the salon for DNA skin damage to be detectable. Most gel clients could easily reach those 12 visits in just six months!! This estimate also relies on meticulous use of the lamps—never exceeding eight minutes total for one full manicure application. That's hardly what happens in a normal setting, where manicurists would prefer to over-cure the polish than accidentally under-cure and have an unhappy customer.