Weird rash of spontaneous combustion fire calls offer lesson in safety, say fire chiefs

A recent rash of fire calls caused by spontaneous combustion has area fire officials shaking their heads at the rarity of several in a row.

The act itself seems mysterious and complicated — a fire starting with no apparent source of ignition — but it's all very scientific. 

Combustion happens when a fuel combines with oxygen to produce heat from a recognizable source, like a match. However, in some circumstances, the trigger that ignited the fire has no definite source.

Spontaneous combustion is the process of a material catching fire by itself. It can happen in a pile of compost or to oily rags in bin or even clean towels taken out of a hot clothes dryer.

According to the National Fire Protection Association an estimated 14,070 fires occur annually from spontaneous combustion.

Area fire chiefs are warning residents to be aware of how these types of fires start and how they can be avoided.

The Brownsville Fire Company responded about 11:30 p.m. on Aug. 27 to a residence on Dodge County Y in after the homeowner noticed smoke coming from a room being remodeled in their old farmhouse.

The culprit was a bucket filled with rags used for varnishing that started to spontaneously combust, said Brownsville Fire Chief Kelly Thomas.

The homeowners quit working on the project about 6 p.m., and five and half hours later, the room was filled with smoke.

“There were two small children in the home and the mom just happened to wake up and thought something didn’t smell right,” Thomas said.

The rags, packed together, produced their own heat, fueled by chemicals, Thomas said. Once the smoldering bucket was taken outside, it burst into flames when it came in contact with oxygen.

“It can be a pretty scary thing when it happens,” Thomas said. “But throwing the rags in a corner or in a heap is an invitation to a heap of trouble.”

The day before, on Aug. 26, a sprinkler system helped save the recently-opened Top Shelf Bar & Grille in downtown Fond du Lac. About 1:20 a.m. a police officer heard the sound of water rushing from the back door of the business. Investigators determined the fire started when rags in a bucket spontaneously combusted.

This time the cause was a pile of clean towels that had just been washed, dried in a clothes dryer and then neatly stacked in a container, said Fond du Lac Fire Dept. Division Chief Troy Haase.

According to an article posted at HK Laundry Equipment, a significant number of fires occur on counters or in laundry carts at laundromats due to spontaneous combustion. Cotton starts to oxidize — a chemical process where one material changes or decays  into another —  when surface temperatures reach 205 degrees Fahrenheit. The normal high temperature setting on a dryer is 190 degrees.

The process is accelerated when the fabric is tightly folded and placed in a confined area. Because it is hot, moist, and has no possible way to release its heat, the oxidation continues to build upon itself, until the garment reaches a critical temperature and bursts into flames.

Haase said that same thing happened on Sept. 21, 2014, at Boda’s Restaurant in Fond du Lac, and involved towels in the basement that had been freshly washed and dried.

He recommends letting clothes cool down after they are pulled out of a dryer, before stacking them and putting them away. Many dryers also offer a cool down cycle setting.

On Aug. 31 the Waupun Fire Department rushed to the scene of a multi-tenant commercial building that was filling with smoke. Fire Chief B.J. DeMaa said when crews searched the building they discovered a smoldering fire on a work bench in a space leased by Home Contractors.

Damage was limited to a work bench in the shop area, started by spontaneous combustion of stain-soaked rags that were balled up on the bench.

“We want to remind folks again, anytime you are disposing of stain-soaked rags, please put them in a non-combustible metal container with a metal lid,” DeMaa said. 

These types of containers can be purchased at local stores like Walmart and Menards. 

Farmers also need to remain diligent, due to the possibility of large manure piles spontaneously combusting during conditions of extreme heat, as well as high-moisture hay piled in storage. Hay insulates, so the larger the haystack, the less cooling that occurs to offset the heat. 

There may be several more instances where spontaneous combustion is the cause of fires within communities, but investigators can't find the ignition source, so the fire is classified as undetermined, Haase said. 

"This could have been the cause of some fires in the past but we will never know because the evidence was destroyed," he said. 

Can people spontaneously combust?

There's been hundreds of reported cases of death by burning up from the inside out, although few have been properly assessed by experts.

According to History.com, cases have been suspected when officials found burned corpses with unscathed furniture around them. For instance, an Irish coroner ruled spontaneous combustion caused the 2010 death of 76-year-old Michael Faherty, whose badly burned body was discovered near a fireplace in a room with virtually no fire damage.

Scientists remain skeptical, and dismiss the theory, arguing that an undetected flame source such as a match or cigarette is the real culprit in suspected cases.

Contact Sharon Roznik at 920-907-7936 or sroznik@gannett.com. Follow her on Facebook at facebook.com/reporterroz/

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