Reason Foam Fails #2:  Unacceptable Fire Hazard

Reason Foam Fails #2

Unacceptable Fire Hazard

Is it really too much to ask that our thermal insulation not be a fire accelerant? After all, thermal insulation can (and should) continuously and completely envelop the buildings we occupy. Foam feeds fires. Foam fails. (See the 13 reasons Foam Fails, here.)

For an idea of what it means to be an accelerant, take a look at the video below, produced by The Cellulose Insulation Manufacturers Association, that compares the burn characteristics of cellulose, fiberglass and foam.(The video’s long version is here.) The spray foam insulation produces a flashover in 44 seconds – a supersonic jet in fire acceleration by thermal insulation.

According to Doug Stewart of Federated Insurance of Canada, the insurance industry refers to foam insulation as "solid gasoline".

Therefore, once we've wrapped our buildings in this fire accelerant:

"Codes require thermal barriers for interiors to reduce the risk of a flash fire and to extend the time at which the foam would reach its auto ignition temperature should a fire originate from other sources."

"Many types of thermal barriers are available on the market today including but not limited to: 1. Gypsum wallboard, 2. Spray applied cementitious, materials, 3. Spray applied cellulose materials, 4. Portland cement plaster, 5. Various proprietary materials."

- Thermal Barriers for the Spray Polyurethane Foam Industry

As described by a 1989 OSHA technical memorandum:

“Rigid polyurethane and polyisocyanurate foams will, when ignited, burn rapidly and produce intense heat, dense smoke and gases which are irritating, flammable and/or toxic. As with other organic [carbon based petrochemical] materials the most significant gas is usually carbon monoxide. Thermal decomposition products from polyurethane foam, consist mainly of carbon monoxide, benzene, toluene, oxides of nitrogen, hydrogen cyanide, acetaldehyde, acetone, propene, carbon dioxide, alkenes and water vapor.”

“One of, the major safety precautions to be taken around organic [carbon based petrochemical] foams is to prohibit sources of ignition such as open flames, cutting and welding torches, high intensity heat sources and smoking.”

Therefore, foam can be particularly hazardous during construction or renovation, as it is often exposed.

Shanghai 2010

In 2010 foam ignition caused by welding in Shanghai China, produced a horrific tragedy, claiming the lives of at least 53 and injuring more than 70 others.

The South China Morning Post reported:

“It was being retrofitted with exterior insulation panels in a pilot energy conservation scheme by the local government. But the flammable polyurethane foam has been identified as a major contributory factor behind the scale of the disaster.”

Foam can have chemical fire retardants in them but they don’t actually prevent the foam from burning - see this new report, Flame retardants in building insulation: a case for re-evaluating building codes, here. However, the retardants do poison our environment (See #1 Dangerous Toxic Ingredients).

The foam industry has developed a new ignition barrier test standard, AC 377 Appendix X. At least one product on the market meets this standard. Per the Spray Polyurethane Foam Alliance press release:

"This established baseline sets the standard by which all alternative ignition barrier systems can be measured: If the modified NFPA 286 test of the alternative ignition barrier takes longer to flash over than the [1/4" thick] plywood baseline (4 minutes and 18 seconds), then the system can be used in all attic and crawl space applications regardless of size or geometry."

But what happens when the ignition barrier is breached or missing? Here is a video of a foam accelerated fire in France in May, 2012, leaving one dead, 10 injured and 94 homes uninhabitable.

France Fire

EXCLU : l'incendie de Roubaix filmé par un voisin by France3Nord-Pas-de-Calais

In November 2012 a Dubai skyscraper - as blogged by Lloyd Alter in Treehugger here - actually burned down its facade, accelerated by its foam/metal sandwich panels.

After several foam accelerated building fires in Frankfurt Germany, the head of the Frankfurt fire department, Markus Frank stated in June of 2012:

"A problem has been detected, it is now not a question of abandoning the insulation of houses, but we must now quickly examine, if we shouldn’t be using other insulation materials..."

(Full English translation article can be read here: Translation: Deadly threat on the wall.)

What other possible insulation materials might we use?

    • Mineral wool? Non-combustible. See here.
    • Cellular glass? Non-combustible. See here.
    • Wood fiber? Fire retarding. See here.
    • Cellulose? Fire retarding.* See here. See video below. (Don't try this at home.)

All help prevent fire spread.

Foam not only feeds fires, but when spray foam is improperly installed it can actually start the fire. As reported by Martin Holladay in 2011 on GreenBuildingAdvisor, the results can be devastating:

"The Massachusetts Division of Fire Safety (DFS) is investigating the causes of three house fires that were ignited while insulation contractors were installing spray polyurethane foam.

According to Tim Rodrique, the director of the DFS, investigators suspect that the fires were caused by the exothermic reaction that results from the mixing of the two chemicals used to make spray foam."

Cape Cod, 2011. photo: Dave Curran

In Woods Hole a $5 million home was severely damaged. The Cape Cod Times, reporting on the Woods Hole fire noted:

"In the Penzance Road fire, Sullivan said firefighters were somewhat stymied due to spray-on foam insulation.

Sullivan said the petroleum-based material is highly flammable and problematic because it repels water. As a result, fire crews were still removing the insulation from the home and putting out hot spots at 2 p.m. [seven hours after arriving to the scene] Thursday. "

And in 2008 a spray foam installation worker was tragically killed. Reported by the Cape Cod Times (here):

"The first sign of trouble came when a co-worker smelled a burning odor and noticed smoke billowing in the fireplace on the floor beneath the attic. He and another worker tried to reach Cowhey and put out the fire with an extinguisher. The two were stymied by the intense heat and smoke, however.

Falmouth firefighter Chris Brown was the first on the scene and the first to gain access to the attic. He said the attic was "fully charged," clouded with thick, black smoke."

Foam doesn't help firefighting. Foam insulation makes firefighting more hazardous and difficult.

We have choices.

For all the reasons foam fails, see our post, Foam Fails.

* Cellulose, as noted at the top, is an approved thermal barrier protecting foam from fire.


Dubai Tower Fire Demonstrates Dubiousness of Using Flammable Insulation, by Lloyd Alter, Treehugger, 2012:

(Video) EXCLUSIVE: fire Roubaix filmed by a neighbor., Daily Motion, France, 2012:

(Article) EXCLUSIVE: fire Roubaix filmed by a neighbor., Nord Pas-de-Calais 3, France, 2012:

Fire guts multimillion dollar Woods Hole home, by Aaron Gouveia, Cape Cod Times, 2011:

Flame retardants in building insulation: a case for re-evaluating building codes, by Vytenis Babrauskas et al., Routledge, 2012

Flammable foam lined Shanghai tower before fire, by Will Clem, South China Morning Post, November 2010:

"Green" insulation suspected as cause of fatal fire, by Aaron Gouveia, Cape Cod Times, 2008:

ICC-ES Approves New Fire Test Protocol for Spray Applied Polyurethane Foam in AC377, Press Release, Spray Polyurethane Foam Alliance,, 2009:

Insulation Fire Hazards On Farms, by Dennis J. Murphy and William C. Arble, PennState, 1988:

Mortal threat to the wall?, by Hermann Wygoda, Frankfurter Neue Presse, 2012: Translation by Floris Keverling Buisman here:

NPFA 286 Insulation Material Comparison Testing, by Cellulose Insulation Manufacturers Association, 2007-2008:

OSHA Safety Hazard Information Bulletin on Fire Hazard of Polyurethane and Other Organic Foam Insulation Aboard Ships and in Construction, By Edward J. Baier, Occupational Safety & Health Administration (OSHA), 1989:

Polyurethane - "solid gasoline", by Doug Stewart, Fenerated Insurance of Canada, 2005:

Thermal Barriers for the Spray Polyurethane Foam Industry, by Spray Polyurethane Foam Alliance, 2005:

Three Massachusetts Home Fires Linked to Spray-Foam Installation, by Martin Holladay, Green Building Advisor, 2011:

Continue the conversation on social media