Space heater and kerosene heater safety: the 3-foot rule, and Japan's lessons on fuel caps and gasoline

Portable heaters keep a cold room livable, and they cause fires every winter in both the U.S. and Japan. U.S. guidance focuses on electric space heaters; Japan, where many homes still use kerosene heaters, adds lessons about fuel. Here are both.

U.S. guidance

The U.S. Fire Administration (USFA) says to place space heaters on a solid, flat surface and keep them at least three feet from things that can burn, and to plug them directly into wall outlets, not into an extension cord or power strip. Ready.gov adds that bedding, clothing and curtains belong in that 3-foot zone, that you should use only heaters certified by a recognized testing laboratory, and that kerosene heaters should be refueled outside after they have cooled.

Japan's lessons

• Electric heaters cause most heater fires. The Tokyo Fire Department says about 80% of house fires caused by heaters in its area involve electric heaters, many from bedding or laundry touching or falling on them, including futons touching heaters during sleep.
• Kerosene heaters: three classic mistakes. Japan's product safety agency NITE found that most kerosene heater accidents come from kerosene leaking from a cartridge tank cap that was not tightened, laundry or other combustibles touching the heater, and gasoline poured in by mistake. Its advice, as published in English by Japan's trade ministry (METI): confirm the fueling cap is tightly closed with no leaks, use fresh kerosene rather than last winter's, and take measures to prevent fueling with gasoline. NITE also asks people to store gasoline only in metal cans approved under the Fire Service Act, separate from kerosene containers.
• Timing. NITE says heater accidents rise sharply from around November and peak in December. Of the fatal kerosene heater accidents in its 2023 analysis, 31 of 47 involved people aged 70 or older.

A start-of-season checklist (our suggestions)

• Inspect cords, plugs and the heater body before the first use; reread the manual.
• Keep 3 feet (about 1 m) clear around the heater: no drying laundry, no curtains, no bedding.
• Turn heaters off when you leave the room or go to sleep.
• Test your smoke alarms, and if you use a fuel-burning heater, install a carbon monoxide alarm and ventilate the room.

Related: Smoke alarms, fire extinguishers and a home escape plan, Power outage preparedness. Our Japanese edition: ストーブ・暖房器具の火災を防ぐ.