The bottom line is that heat and plastic have been proven hazardous. This was a rumor we heard about competitors products until our elderly customer brought his Polaroid image of his plastic cased heater that was melted. By the way, this is why Solar Comfort is not plastic.
This is not a problem with the Infrared heat lamps that Solar Comfort uses as they have been designed for many years to be used for heating. I recently did a test where I folded a common piece of copy paper. I touched one end to a Quartz bulb (this is the bulb that Edenpure, SunTwin, SunHeat and ComfortZone uses) and with in 5 seconds the paper was fully burning. I did the same test to our Infrared lamps and after 3 minutes all that happened was a discoloration of the paper.
The problem is that quartz gets very hot. When a part fails in the quartz systems the heat can not get out of the unit and builds too much heat. Think of it this way, perhaps a fan breaks down and a heat sensor breaks down as well. The heat stays in the unit and can not get out making it dangerous.
Recently a customer of ours who owns the competitors product said that his unit kept shutting down. He called the manufacturer and they said remove the filter as it is getting too hot inside and tripping the heat sensor. He thought it was odd that he was being told not to run the filter in which the product was made to use.
Solar Comfort is by far the safest in its class bar none! See the image of our customer's plastic heater for yourself in the Polaroid image. Also read this article by a former customer service rep for our competitors product: