August 16, 2001
The Office of the Fire Marshal has received a number of inquiries relating to consumer
products that claim to clean chimney flues when burned in a fireplace. These products
may take the form of logs or powder additives.
Following an investigation of this issue, the Office of the Fire Marshal has identified the
following concerns regarding the effectiveness and safety of these products:
Product literature notes a removal rate of up to 60% of the creosote from the chimney.
In comparison, chimneysweepers can typically remove 75% to 90% of the creosote
deposits. Therefore, these chimney-cleaning products may not adequately remove
creosote to prevent chimney fires.
Marketing materials may give the impression that the use of these products is a
substitute for a chimneysweeper and that no other action is required. However,
proper cleaning of the chimney is essential to fire prevention and compliance with the
Ontario Fire Code.
These products claim to cause the creosote to flake off the chimney and fall into the
fireplace. There is however the possibility, based on the design of a typical North
American masonry fireplace, that some of the deposit can accumulate on the smoke
shelf situated behind the damper thus affecting the damper’s operation. Similarly, if
these products are used on a flue or flue pipe that is installed with an offset or at an
angle, there is the potential for the deposits to become lodged in the elbows, resulting
Fire departments that receive inquiries from members of the public concerning the use of
these products are encouraged to point out to them the concerns mentioned above. In
addition, inquirers should also be reminded of the requirements stated in Sentence
22.214.171.124.(1) and Article 126.96.36.199. of the Ontario Fire Code:
188.8.131.52.(1) Chimneys, flues and flue pipes shall be inspected
(b) when any appliance is added to it, and
(c) after any chimney fire.
184.108.40.206. Chimneys, flues and flue pipes shall be cleaned as often as necessary to keep
them free from accumulations of combustible deposits.
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