City of Ferndale sends warning about 'spontaneous combustion'

FERNDALE, Mich. (WXYZ) — The city of Ferndale put out a warning this month: two recent fires have been caused by spontaneous combustion. Whether it’s a coincidence or an uptick in unsafe practices is unclear.

“Be safe and be careful, this happens more often than you think,” said interim Fire Chief Jack Peshe.

One of the most recent fires happened at a dry cleaner located near 9 Mile and Livernois. Peshe, who also serves as the Fire Marshal, said a number of investigators determined that the cause of the fire linked to a number of rags that were dropped off for cleaning that contained oils and grease from a restaurant.

The most common type of spontaneous combustion fires are caused by improperly disposal of oil stained, or soaked, rags. Everything from oil-based paints and stains, to linseed oil, fatty oils from restaurants, automotive oils, varnishes and paint thinners can combust when they oxidize. Rags can heat themselves through the oxidation process, but Peshe noted that in many cases people use cold water to wash rags with these substances which fails to remove the oil — if you dry them and pile them up it can speed up the process.

“The oils get tossed into a bit and they they go to get washed, and people wash them in cold water as opposed to hot water,” said Pete. “You fold ‘em back up and the molecular process has already started, where the rags will build up enough heat from that residue, where it’s still there even though they washed the rags — that’s when it begins the combustion process.”

That’s why many auto shops and companies that work with oils typically keep a steel can with a lid on it to store used rags. It’s one way to avoid issues. Peshe said that if you use oils and cleaners within your home, it’s a good idea to clean them with hot water and leave them outside to dry thoroughly in the sun for 24 hours. He recalled one case where a pile of oily rags in a workshop got thrown into a bucket with saw dust. Though the fire was small enough to put out with a fire extinguisher, it caused more than $5,000 worth of smoke damage.

The fire department has even put out an easy-to-follow diagram to show best practices when it comes to cleaners, oils and household use.