Special Topics in Safety Management

Space Heaters — Should You Allow Them?

As winter approaches and temperatures drop, you may be faced with the question of whether to allow the use of portable space heaters in the colder areas of your workplace. So, should you?

Space Heater

There are no federal workplace safety rules that prohibit portable electric space heaters in the workplace. OSHA rules do require that electrical equipment must be used according to manufacturer specifications on the unit’s label and in the user manual. And extension cords, if used, must be rated to handle the electrical load (Many employers prohibit their use with space heaters.).

There’s no question that space heaters can pose a major workplace fire safety hazard. Fires can be caused by space heaters without adequate safety features, space heaters placed near combustibles, or space heaters that are improperly plugged in.

Statistics about damage caused by space heaters in the workplace are not readily available, according to the federal Office of Compliance. But public information is available on the effects of poorly utilized space heaters in the home. Between 2005-2009, space heaters caused 32% of home heating fires or structural fires and resulted in thousands of injuries as well as civilian deaths.

Just Say No to Space Heaters?

It would be easy to “just say no,” and many employers discourage the use of space heaters or ban them outright, sometimes citing edicts from their insurance companies.

But the reality remains that no matter how much you tweak the HVAC system, no matter how much weather stripping you add, some areas of the workplace can be just plain COLD. On top of that, some workers may have medical conditions that require extra warmth even in “normal” (68–76 degrees F) work temperatures.

And space heaters can be used safely in the workplace if proper precautions are taken. Consider these guidelines from Stanford University’s SLAC National Accelerator Laboratory (which has a very thorough environment, safety, and health manual):

The compliant use of electric space heaters is permitted, as a temporary measure, if the following requirements are met:

  1. The building manager has checked that use of the space heater will not cause problems and that the need can’t be met by adjusting the building HVAC system.
  2. The space heater is kept away from any combustible material. (Refer to the manufacturer’s instructions.)
  3. The space heater is always turned off when the area being heated is not occupied.
  4. Nothing is ever placed on top of or touching the space heater.
  5. The space heater is plugged directly into a wall outlet. Do not use extension cords or power strips because of the risk of overheating and possibly catching fire.
  6. The space heater is in plain sight.

At Tufts University, the fire marshal sets out some additional rules, including:

  • All heaters must be Underwriters Listed or Factory Mutual approved for their intended use.
  • Heaters must have a thermostat to automatically shut down the unit when the desired temperature is achieved.
  • Heaters must have a tip-over automatic shut down feature.
  • Heaters must be kept at least 3 feet from all combustible materials, e.g., file cabinets, desks, trash cans, and paper boxes.
  • Heaters must be monitored when in operation.
  • Heaters missing guards, control knobs, feet, etc. must be taken out of service immediately and repaired by a competent person. Do not use heaters in rooms that will not be continually occupied.
  • Do not use portable space heaters if small children are expected in the area.
  • Space heaters of any type are prohibited in laboratories.

Employers that allow the use of space heaters often specify exactly what types—and what features—are allowed. Stanford’s SLAC lab has several of the same requirements as Tufts, and it also sets out these specifications:

Fully Enclosed Space Heaters

A fully enclosed space heater that, by design, has no external surfaces that reach temperatures capable of igniting material placed against the surface. For example, an oil-filled radiant heater must meet the following specifications:

  • If it has any exposed metal parts, it must have a grounded three-pronged plug
  • It must not take more than 1,500 watts to operate
  • A space heater with an open grill must have a fan forcing air through the grill.

Space heaters are obviously just one of many potential workplace fire hazards. Here is more information about fire hazards in the workplace.