Residents Visitors Business Leisure I Want To...
Public Safety
City Services
Online Services
Proper Disposal of Ashes 

Fireplaces, Pellet Stoves, Woodburners, etc.

With the increased use of outdoor fireplaces and alternative heating/cooking methods the Thornton Fire Department would like to remind you of proper ways to dispose of leftover ashes.  Improper ash disposal from indoor/outdoor fireplaces and wood burning stoves causes thousands of fires every year. 
Many people do not realize the length of time required for ashes to cool enough for disposal.  Even after several days a pile of ashes can hold enough heat to reignite and start a fire.  Four days (96 hours) is the minimum cooling period for ashes.    Extra care should be used in the storage and final disposal.

  • Make sure there are no hot spots left in the ashes.  This is done by soaking them in water or letting them sit for several days and double checking for hot spots.   This would apply to charcoal grill ashes as well.
  • All ashes should then be stored in a fire-resistant metal container with a tight fitting cover.  This helps keep air from blowing through and disturbing ashes which can leave hot coals exposed for reigniting.  Approved containers are available at local retailers.  They should NEVER be disposed in a plastic garbage box or can, a cardboard box, or paper grocery bag.  Never use a vacuum cleaner to pick up ashes.
  • The metal container should be placed away from anything that can burn.  It should not be placed next to a firewood pile, up against or in the garage, on or under a wood deck, or under a porch.
  • After sitting for a week in the metal container the ashes are then safe to dispose of in your trash.

As a safety precaution keep anything that can burn at least three feet away from a fireplace, wood stove, or any other heating equipment, and create a three-foot “kid-free zone” around open fires. Also, make sure the fireplace has a sturdy screen to stop sparks from flying, and never leave a fire unattended, particularly when children are present.

For open burning restrictions, please visit the Fire Department web-page at

ASH disposal.pdf


City of Thornton
9500 Civic Center Drive, Thornton, CO 80229
Contents ©2014 City of Thornton
All rights reserved