my friend had one years ago, it was a about two years old, he left it on in a bedroom and hours later he opened the door and the oil had escaped through a bad seal, the room was full of oil mist it covered everything, ,it was reported to trading standards but never heard anything , he had to claim on insurance for damages as you could not get the oil off everything, BUT if a,child had been asleep in that room god know what would have been the outcome