Last year, 340 household clothes dryer fires were reported in Ontario. Almost one third of these incidents were due to a lack of maintenance.
Provincial statistics indicate that, on average, 300 clothes dryer fires are reported annually. Although there have been no fatalities within the past ten years, up to 15 injuries and a few million dollars in property damage result each year.
The design and internal mechanism of most clothes dryers are similar. The majority come in two sizes: full and compact. (Compact dryers are commonly found in apartments stacked above the washing machine to save space.)
Heat for clothes dryers is provided by an electrical, natural gas or propane source, with electrical being the most common. At this time, fire hazards do not appear to be associated with any particular brand of clothes dryers.
Normal clothing is dried at an air temperature of about 60°C while permanent press clothing is dried at about 50°C. Clothing made of cotton fabric or man-made plastic material when combined with the accumulated lint in the dryer has an approximate flash ignition and auto-ignition temperature above 200°C.
Safety features built into clothes dryers include two or three high limit switches at the heating elements which stops any thermal runaway condition by cutting off the power at about 120°C. Under normal conditions, there is a considerable margin of safety before the ignition point of clothing is reached.
In addition, the dryer drums within the dryer cabinets are designed to act as a fire barrier to slow the spread of fire.
Major fire hazards associated with clothes dryers include:
- lack of maintenance;
- improper installation (venting);
- drying flammable materials;
- accumulation of lint;
- use of plastic ducts.
The lack of maintenance/care and improper installation (i.e. incorrect venting) are the leading causes of fires in clothes dryers. Fires also occur when flammable materials are inadvertently put into these appliances. If a fire occurs, it will often start within the drum of the dryer and be fueled by lint that has accumulated in the dryer cabinet.
In the event that plastic ducting is used to vent the dryer instead of metal ducting, the fire will not be contained within the dryer if the plastic ducting ignites or melts.