It is safe as long as the temps are not too high. For most using say a 60 watt bulb there are no real issues except for leaves of live plants that get too close drying out and getting burnt tips. I would keep artificial plants a bit away from the source to make sure your chameleon doesn't get too close and get burned. If you use a more intense type of bulb you may want to keep the live plants trimmed away from the light.