Any sort of heating element has some sort of safety issue associated with it. That's just how electronics and heat roll.
RHPs? Make sure they've properly outgassed, don't let too much heat reflect back at the unit, maybe get them serviced every few years to replace fuses and the like. Heat bulbs? Don't spray them with water when they're hot, don't let your herps touch them, watch for electrical shorts. CHEs? Definitely don't let anything touch them. Heat tape? Don't get me started.
My point is that any heating element can fail, like the others have said. Avoid obvious junk and untested technology, follow the manufacturer's instructions for use, remember your safety regulators and relays, maintain and check your equipment, and you should be good.
For what it's worth, the only consistent, widespread scuttlebutt I've heard in the VE versus ProProducts RHP debate is that the VE panels seem to be a bit stinkier when offgassing. Since offgassing smells seemed to be tied to the type of plastic used in the unit's shell, which does appear to be different between the two companies... yeah, I could potentially see that. People who have used both brands can chime in on this front. I'm curious.
Both definitely stink when off gassing. Can't recall offhand which was the worse offender at my place to be honest though. Pro Heat claims no off gassing but they definitely stink for a bit when brand new and fired up.