Spontaneous Combustion – Dos & Don’ts

Spontaneous combustion is the occurrence of fire without the application of an external heat source. Fires can originate from oil-soaked rags, sanding dust, compost, mulch, and leaf piles. Clothing soaked in petroleum or other oils which is laundered and then dried is also a statistically significant source of home dryer fires.

As you plan summer home projects, or if you are a contractor who regularly deals with the aforementioned debris, please take the following into consideration to help prevent spontaneous combustion:

  • Read and adhere to all directions and warnings on paint, stain, and cleaning products.
  • Dispose of rags, brushes, etc. used with the above in an approved container or spread soiled rags in a single layer on a non-flammable surface and allow to air dry.
  • Store compost, mulch, and leaf piles well away from any buildings.
  • If laundering stain, finishing oil, or other flammable liquid-soaked clothing, be aware that the wash cycle may not remove all of the product.  Subsequent drying could cause a fire.
  • Sanding debris, including sanding equipment and particularly filters and dust collection and vacuum bags should be disposed of according to manufacturer’s instructions.  Dust collected has the potential to spontaneously combust several hours after work is completed.
  • According to the National Fire Prevention Association, spontaneous combustion can be prevented in
    • Agricultural products: Spontaneous heating in agricultural products can be prevented by control of moisture. Proper drying and adequate airflow will limit heating. Regular checks of temperature should be made.
    • Oily Rags: Rags that have absorbed oils such as linseed oil or turpentine should be kept in well-covered metal cans and thoroughly dried before collection or transport.1
      • 1Fire Protection Handbook. 20. 1. Quincy, MA: National Fire Protection Association, 2008. 6-288 – 6-292.
    • According to Consumer Reports, if paint rags catch fire outside, extinguish the fire by dousing with water or covering with sand or dirt. Don’t disturb them until you’re sure the fire is out. If paint rags catch fire indoors, call the fire department, get everyone outside, then (and only then) try to put the fire out with an extinguisher. If you cannot put out the fire, get out of the house and wait for the fire department.
  • For more information, visit: Spontaneous Combustion Fact Sheet NFPA