Those homes are also poorly insulated, and probably let gasses out much more easily than modern well-sealed homes. I didn't see kerosene heaters in new homes i

Those homes are also poorly insulated, and probably let gasses out much more easily than modern well-sealed homes. I didn't see kerosene heaters in new homes in Japan, probably for the same reason. As such, I would be hesitant to use a kerosene heater in my home without investigating it in much more detail. (It's a theoretical issue for me as my geographical area has more NG than it can use)