Any lighting fixture can theoretically catch fire or cause a fire... A properly used, commercially obtained PC, T5, or MH fixture manufactured by a trusted company and purchased from a reputable vendor shouldn't be a fire hazard. There were alledgedly some exceptions in the past, but I'm not aware of any of the recently produced fixtures having this kind of problem. I could be wrong, but if brand X's model Z fixture really caught fire consistantly and is unsafe, I think it would be plastered all over the message boards.