Investigating Claims Involving Spontaneous Combustion

Spontaneous combustion causes more than 14,000 fires a year, according to the National Fire Protection Association. That’s why everyone should know about the materials that can cause spontaneous combustion, said Daniel Hogan, an attorney with the law office of Robert A Stutman.

Hogan, speaking at the Property Loss Research Bureau’s (PLRB) national conference held in Boston last month, said spontaneous combustion is the result of a chemical reaction that occurs when combustible materials combine with oxygen or when oils and resins dry out. The reaction generates heat.

Stain-soaked cotton rags is a common, well known source of spontaneous combustion fires.

According to Timothy Anderson, subrogation manager for Markel Services Inc., the following materials are some examples of materials that can spontaneously ignite:

• Charcoal – high
• Fish meal – high
• Linseed oiled rags – high
• Brewing grains – moderate
• Latex foam rubber – moderate
• Hay – moderate
• Manure – moderate
• Wool wastes – Moderate
• Baled rags – low to moderate
• Sawdust – possible
• Grain – low

The panelists discussed some case examples including paint overspray, rags soaked with vegetable oil and boxed latex rubber gloves.

Spontaneous combustion fires associated with homes under construction typically occur when construction is 90-95 percent complete because that is the time when finishing work is performed and materials prone to spontaneous combustion are used, e.g., wood staining and/or floor finishing materials.

Anderson described another example of polyurethane added two weeks prior to wood flooring, while dry to the touch, is still curing and experiencing an exothermic chemical reaction. When the flooring is sanded, this causes frictional heat and the resulting dust has significant potential to combust.

Another example is mulch and compost piles, Hogan said. There are standards on how to tend to mulch and compost piles because the decomposition causes heat.

According to the panelists, key terms associated with spontaneous combustion include:

• Self-heating
• Spontaneous ignition or self -ignition
• Thermal runaway
• Smoldering
• Critical stacking

The key to subrogation in spontaneous combustion claims is evidence. Often, the fuel source, ignition source and oxidizing agents are consumed in the fire leaving virtually no physical evidence.

According to Hogan, there are instances where spontaneous combustion is the cause of a fire but the fire marshal’s report will note the ignition source cannot be found so the cause of the fire is classified as undetermined. This occurs because the ignition source itself, stained soaked rags, was also the fuel that fed the fire. Because the ignition source and fuel are one in the same, a spontaneous combustion fire will naturally consume the ignition source and leave very little physical evidence behind.

“Uphill battle without physical evidence,” Hogan said.

In addition, there is the potential for recovery when there is no manufacturer warning or when a product is misused.

Anderson recommended assigning a fire investigator to go to the scene immediately following larger fires. He or she can begin the initial investigation at the scene where witnesses can be interviewed. MSDS sheets and exemplar products might be recoverable at the scene as well.

“Circumstantial evidence is often better than direct evidence,” Hogan said.