Some restaurants’ kitchen fires don’t start with a dramatic flare-up. They start quietly, in a pile of rags no one thought twice about. Believe it or not, the rags that are used to clean up cooking oil and grease residue can ignite on their own – no spark needed – and create a spontaneous combustion fire.
When grease-laden rags are stored in a pile, especially in a warm kitchen in summer, heat is generated as oils and grease that are trapped in the linen oxidizes. The heat within the pile or bundle of rags has nowhere to escape. It can become hot enough to spontaneously combust, starting a fire. Even the National Fire Prevention Association speaks to this severe hazard! A study by the Consumer Product Safety Commission found that oil residue as low as 3 percent in fabrics can lead to spontaneous combustion and ignition.
The good news: it’s a preventable hazard, and a few operational shifts can reduce the risk.
Society Insurance is sharing their tips for restaurants to drastically lower the chance of a spontaneous combustion fire, like how to launder, store and dispose of rags.
Tips for Handling Greasy Rags in Your Commercial Kitchen
- It is best to contract with an outside professional laundry service to clean your rags and linens.
- If you choose to launder your own rags, your appliances should be commercial-grade and listed or approved for laundering of greasy or oily materials. You can usually determine if the appliance is approved for laundering these materials in the owner’s manual of the appliance. You should never use residential grade or non-approved appliances for laundering these materials
- When laundering, only use water detergents or solutions approved to launder grease-contaminated cloths.
- Appliances should always be used properly and maintained in good working condition. Enforce a strict preventive maintenance schedule, periodic inspections, and daily vent and lint trap cleaning. Keeping a written log of maintenance items is a good practice.
- Do not leave laundry in the dryer unattended or leave laundry in a dryer for an extended period (i.e., overnight). This can allow heat to build up. Remove laundry from the dryer promptly when the cycle is done.
- Grease-contaminated cloths or waste should be placed in listed or approved oily waste containers with self-closing lids. Store clean cloths separately and away from dirty cloths.
- Only use rags and linens designed for your specific use. Dispose of rags and linens when they are excessively soiled, stained or even after laundering when the materials leave a greasy sheen on your hands after being handled. Grease or oils will accumulate in the fabric of the rags and linens over time
Recent Incidents of Spontaneous Heating, Ignition or Combustion
Spontaneous heating, ignition and combustion are more common in commercial kitchens than you might think. Below are a few incidents from around the country.
- May 6, 2026, Ohio – “Thurman Cafe owners: Fire could have started due to spontaneous combustion.” According to a member of the owner’s family, “We normally keep our dirty rags behind the building. A laundry service picks them up on Mondays and drops off clean ones. The latest thinking is that some of those soiled ‘bar rags’ may have spontaneously combusted, allowing fire to enter the rear of the building.”
- February 25, 2022, Oregon – “Freshly washed towels spontaneously combust, forcing restaurant to close for months.” According to the article, “The cause of the fire? Something not out of place in a restaurant: a towel … Every day we wash towels and get them ready for the next day,” owner Brian Sung said. “So, we brought up the washed, cleaned towels in this room here – and they spontaneously combusted.”
- February 22, 2021, Tennessee – “‘Spontaneous combustion of kitchen waste’ cause of fire at Rutherford County store.” Lt./Asst. Fire Marshal Joshua Sanders said, “In this case, multiple rags used in the cleaning of the market’s kitchen were improperly discarded in a bucket inside the kitchen area. The cooking-oil soaked rags are prone to spontaneous heating phenomenon which results when the oils begin to oxidize, creating a significant amount of heat within the material.” Sanders said this is the second time this type of fire happened at this business. The first was on October 13, 2020, when a clothes dryer containing the same types of rags caught fire.
- April 9, 2019, Wisconsin– “Spontaneous combustion causes fire at Madison east side deil.” The deli staff took approximately 50 small towels used for cooking and cleaning purposes to the laundromat, according to a press release. The towels were washed with traditional detergents. After washing, the towels were dried at a high temperature for 60 minutes, then placed in wire baskets and stored under a prep table at the restaurant where they later ignited.
- August 13, 2019, Oregon – “‘Spontaneous combustion’ in kitchen caused fire that destroyed Otis Café.” The news reported “the fire that destroyed the iconic Otis Café along Highway 18 was caused by ‘spontaneous combustion’ in kitchen garbage, investigators said. Investigators say the fire started near the cooking range, and was caused when a bucket of paper towels absorbed with oil and grease spontaneously combusted.”
As we all know, rags and towels are handy for cleaning up cooking oil and grease residue at restaurants and bars. However, their usefulness can also make them a severe fire hazard.
Fortunately, by getting the details right on proper handling and care of greasy rags, you can help snuff this risk out. Small details like this make a difference.
Download this “Safe Handling of Fabric Rags & Linens” handout to share with your staff.
This information is provided as a convenience, and it must not be assumed that it has detected all unsafe acts or conditions. This information is not professional advice; it is designed to assist you in recognizing potential safe work problems and not to establish compliance with any law, rule or regulation.
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