is it safe to sleep with kerosene heater
Because kerosene heaters are usually unvented, all combustion products are released into the indoor air. Among these are low levels of nitrogen dioxide and carbon monoxide. An improperly adjusted, fueled, or poorly maintained kerosene heater will release more pollutants, particularly through incomplete combustion. Use of a kerosene heater in an improperly ventilated home poses an extreme risk to life. If oxygen is burnt faster than the extraneous atmosphere can leak into the room to replenish the burnt oxygen, the proportion of carbon monoxide rapidly increases. Since the monoxide can not escape, any person in the room will fatally succumb to the poisonous gas. Human senses only detect an excess of carbon dioxide, and death occurs before any occupants of the room sense there is something amiss. Most manufacturers recommend that a window or door be left cracked open. Kerosene heaters should not be left unattended, especially when sleeping. A kerosene heater, as any heater that uses organic fuel, can produce dangerously high amounts of soot and carbon monoxide when running out of oxygen. Failure to follow safety precautions could result in asphyxiation or carbon monoxide poisoning.
Kerosene heater