Controlling home furnishing fires
Fire sprinklers address the upholstered furniture hazard.
NFPA Journal®, January/February 2008
A new study released in October 2007 by Underwriters Laboratories in conjunction with the Fire Protection Research Foundation adds credibility to the characterization of polyurethane foams and similar materials as "solid gasoline." The furnishings we surround ourselves with today pose a higher level of risk than in past decades, resulting in faster-developing fires and less time for escape.
The UL study examined 27 combinations of materials now commonly found in homes, and found that synthetic materials produce hotter fires and more toxic smoke than natural furnishings. According to UL Consumer Affair Manager John Drengenberg, "the time needed to escape some types of fires has been reduced to as little as three minutes from 17 minutes only three decades ago."
The need to address these very fast fires is becoming a concern in places likeNew Zealand, where authorities are demanding that fire protection engineers use specific design fires when developing performancebased designs. While engineers often explore the effects of varying growth rate fires termed "slow," "medium," "fast," and "ultra-fast," new research conducted at the University of Canterbury suggests that about 20 percent of the fires involving a single upholstered chair exceed the standard characterization of a "fast" fire, in which the fire grows to a size of 1 megawatt (approximating a fully developed upholstered chair) within 150 seconds. The fire continues to grow if other furniture becomes involved; an upholstered sofa alone can produce a 4-megawatt fire. For a reasonable level of safety in the broad range of occupancies that use upholstered furniture, the "ultrafast" fire scenario should be addressed.
None of these research results come as a surprise to the NFPA Committee on Automatic Sprinklers. In 1986, a free-burn test was conducted on the residential corner scenario that is the basis of residential sprinkler product approval. The test involved polyurethane foam furniture and showed that, without sprinkler intervention, the residential sprinkler corner scenario was essentially an ultra-fast fire that grew to a peak heat release rate of over 5 megawatts. A standardized laboratory version of the upholstered furniture scenario is used in the testing and listing of each model of residential sprinkler.
The good news is that residential sprinklers are already designed to combat the ultra-fast fires that today’s furnishings can produce. The bad news is that fire sprinklers must be installed in homes if they are to be successful in controlling these fires, and there are still relatively few communities that have taken this important step forward.
Russ Fleming, P.E., is the executive vice-president of the National Fire Sprinkler Association and a member of the NFPA Technical Correlating Committee on Automatic Sprinklers.