Ministry of the
Solicitor General

Consider Fire Safety when Storing Wood Chips

Consider Fire Safety when Storing Wood Chips

By Yosh Imahori, P. Eng.,
Fire Protection Engineer, OFMEM

In light of recent storms, which resulted in clean-up efforts of downed trees by homeowners, businesses and municipalities, there has been an increased need to manage the storage of wood chips. The accumulation of wood chips in piles can pose a fire risk if not managed correctly, especially if the wood chips contain bark and other impurities that cause the chip piles to be more susceptible to internal heating.

How can fire start in a wood chip pile?

Fire in wood chip piles can either be surface burning or internal. Surface fires are often caused by exposure from another fire or from other ignition sources close to the piles. Internal fires are caused when heat produced by the microbial decay of wood is not readily dissipated. Interior pile temperatures can increase and when the heated chips are exposed to sufficient air through aeration or pile agitation, rapid combustion may occur. Generally, incidents of fires in wood chip piles have been of a smouldering nature, but if enough heat is generated or sufficient care is not taken, a more extensive fire could develop.

Some considerations

Items to consider when storing wood chips in temporary piles:

  • Limit pile sizes
  • Avoid compaction of the pile
  • Provide fire department access to the pile
  • Provide pile with periodic wetting, especially during dry conditions
  • Avoid maintaining large piles of wood chips for an extended period
  • Check piles periodically for any signs of hotspots, smouldering or unusual odour that could indicate the on-set of a fire
  • Keep other combustible materials away from wood chip piles
  • Eliminate any ignition sources near the wood chip piles
  • Prepare a pre-fire plan.

For more information, contact your local fire service for assistance in the safe management of wood chip piles, refer to Subsection 3.2.3. of the Ontario Fire Code about the outdoor storage of wood chips and/or click on the Office of the Fire Marshal and Emergency Management Technical Guideline OFM TG-03-1998 Storage of Wood Chips.