Rags and towels are used every day for cleaning up cooking oil and grease residue at restaurants and bars. However, their usefulness can also make them a severe fire hazard. Spontaneous combustion occurs when heat is generated through rapid oxidation. This causes these fabrics and oils to reach their autoignition temperature and ultimately ignite. As grease and oil become trapped within the fabric fibers, the chance of spontaneous combustion increases greatly.
Here we’ll go over some tips on how to handle greasy rags to prevent spontaneous combustion.
5 Tips for Handling Greasy Rags in Your Commercial Kitchen
Fortunately, by getting the details right on proper handling and care of greasy rags, you can snuff this risk out. These tips will help make a difference:
1. Use Commercial-Grade Equipment and Detergents
Use only appropriate commercial grade washer-extractor appliances that are designed and approved for washing greasy rags; and only use commercial grade detergents that are also designed and approved for washing greasy rags. Never use standard washers and detergents, they are not designed to be capable of removing the grease contaminants. Always read and follow all appliance manufacturer instructions, all appliances should be commercial grade and listed or approved for laundering greasy rags. Pre-soak contaminated rags and fabrics to remove as much grease and oil as possible, before washing them in a commercial grade washer-extractor appliance.
For effective pre-soaking, create a solution using commercial degreaser mixed with hot water (follow manufacturer’s ratios). Submerge the rags completely for at least 15-30 minutes before washing. This water submersion method helps break down oil molecules and makes them easier to remove during the wash cycle. Always wear gloves when handling contaminated materials and ensure adequate ventilation in your pre-soaking area.
2. Proper Drying Techniques
Remove rags and fabrics from the dryer as soon as the cycle is done. Refrain from leaving them in the dryer for long periods of time. They can continue to spontaneously heat inside and outside of a dryer and must properly cool down to reduce the risk of spontaneous combustion.
When using commercial dryers, consider these additional safety measures: Use low to medium heat settings rather than high heat, which can cause oil residue to bake into fibers. If weather permits, consider air-drying clean rags outdoors on non-combustible surfaces like concrete or metal racks, positioned at least 10 feet away from buildings, vehicles, or other combustible materials. When laying rags flat to dry, ensure they don’t overlap or pile up, as this can trap heat and create hot spots. Allow at least 24 hours of cooling time before storing dried rags, even those that appear completely clean.
3. Safe Storage Practices
Store dirty fabrics in listed or approved containers with self-closing lids. Store clean cloth separately and away from dirty cloth.
Proper storage goes beyond just using approved containers. Metal containers with tight-fitting, self-closing lids that meet UL (Underwriters Laboratories) or FM (Factory Mutual) approval standards are recommended. Never store more than 60 pounds of oily waste in a single container. Position storage containers away from heat sources, electrical equipment, and high-traffic areas. Empty waste containers daily, or more frequently during high-volume cooking periods. Clean storage containers regularly with degreasing solutions to prevent residue buildup that could contribute to spontaneous heating.
4. Professional Laundering Services
Consider contracting an outside vendor who specializes in laundering greasy rags and fabrics.
Professional laundering services offer several advantages over in-house cleaning. These vendors use industrial-grade equipment specifically designed for removing oil and grease, employ specialized cleaning processes that reach higher temperatures than commercial equipment, and provide regular pickup schedules (typically 2-3 times per week for busy kitchens). When selecting a vendor, verify they’re licensed to handle oily waste materials and ask about their cleaning processes and temperature controls. Many professional services also provide clean replacement rags during pickup, ensuring you always have an adequate supply.
5. Prevention During Use
Preventing fires starts with how we handle rags during daily operations. Never pile or stack used rags in corners, on counters, or in bins without proper ventilation. Instead, spread them out in approved containers to allow air circulation and prevent heat buildup. Designate specific areas for used rag collection and train all kitchen staff on proper disposal procedures. Consider using different colored rags for different cleaning tasks—this helps prevent cross-contamination and makes it easier to identify which rags have been exposed to oils and grease. Replace heavily soiled rags immediately rather than continuing to use them throughout the shift.
Safe Disposal Guidelines and Local Regulations
Proper disposal of greasy rags extends beyond your kitchen to compliance with local and federal regulations. Many municipalities classify oil-soaked rags as hazardous waste, requiring special handling and disposal methods. Contact your local environmental protection agency or waste management authority to understand specific requirements in your area.
Most communities offer household hazardous waste programs that accept oil-contaminated materials from businesses. These programs typically operate on scheduled collection days or at designated drop-off locations. Some areas require businesses to register as small quantity generators if they produce significant amounts of oily waste.
For immediate disposal needs, never throw oil-soaked rags in regular trash bins. Instead, place them in water-filled metal containers until they can be properly disposed of through approved channels. The water prevents oxygen from reaching the oils, significantly reducing fire risk. Add a small amount of detergent to the water to help break down oil residues.
Recent Incidents of Spontaneous Heating, Ignition or Combustion
Spontaneous heating, ignition and combustion are far more common in commercial kitchens than you might think. Below are some recent notable incidents.
February 22, 2021 Rutherford County, Tennessee – ‘Spontaneous combustion of kitchen waste’ cause of fire at Rutherford County store. News Channel WKRN reported: 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.
August 13, 2019 Lincoln City, OR – ‘Spontaneous combustion’ in kitchen caused fire that destroyed Otis Café. News Channel KATU 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.” The Newport News Times reported on the same incident and date: “Fire-damage evidence indicated the fire’s origin was in the cafe’s kitchen, near the cooking range. Investigators concluded the cause was spontaneous combustion of combustible items such as paper towels absorbed with oil and grease waste, improperly discarded underneath the gas range in a plastic bucket. Spontaneous ignition can occur with the combustion of a material by an internal chemical or biological reaction that may produce sufficient heat to ignite the material. This may be a slow process.”
July 22, 2019 Peoria, IL – Greasy Rags Cause Fire At Obed And Isaac’s. News Radio WMBD 1470 reported: “A fire located in the kitchen of Obed and Isaac’s, 321 NE Madison in downtown Peoria. An employee reporting for work around 7 a.m. Monday found moderate smoke in the kitchen area, according to the Peoria Fire Department. Firefighters arrived to find a plastic bin containing greasy rags that had been used for cleanup that was on fire. The bin was removed from the building and the fire was extinguished with a pressurized water can.”
April 9, 2019 Madison, WI – Spontaneous combustion of kitchen towels started Stalzy’s fire. The Associated Press (AP) carried a Wisconsin State Journal report: Fire investigators have ruled a Sunday night fire at Stalzy’s Deli on Atwood Avenue was caused by the spontaneous combustion of small kitchen towels. “On Sunday afternoon, deli staff took approximately 50 towels used for cooking and cleaning purposes to a laundromat,” Schuster said. “They were washed using traditional detergents and then were dried at a high temperature for 60 minutes. The towels were then placed in a wire mesh basket and stored underneath a prep table at the restaurant. The towels never fully cooled down, and hours later they spontaneously ignited.”
January 9, 2019 Beaver Dam, WI – Fire Chief warns of spontaneous combustion from booking oil-soiled rags. The Daily Dodge reported: “The Beaver Dam fire chief says there has been an increase in the number of fires caused by spontaneous combustion from oily rags. Once thought to be an industrial or wood shop issue, Chief Alan Mannel says there has been an uptick of such incidents in kitchens, taverns, laundromats and restaurants. A local bar and grill recently had a close call. There was a slight smell of smoke and patrons complained of burning eyes. Fire officials used a thermal imaging camera and noticed that a stack of towels was warm. When the towels were moved, they burst into flames. Upon further investigation, Mannel says he discovered that the towels had been used to clean up cooking oils and that fuel, combined with heat and oxygen, is a recipe for fire.”
June 23, 2014 Danville, VA – Fire Experts: Towels Used For Cleaning Can Spontaneously Combust After Washing, Drying. News Channel WSET reported: “We do see some really odd things occurring in fire investigations, ” said Rockingham Co. Fire Marshal Robert Cardwell. In Reidsville and Rockingham County, fire crews have responded to multiple calls at laundromats, restaurants, and even homes where towels have randomly ignited after being washed and dried. Cardwell says many people make the mistake of using a towel to clean up oily kitchen messes. If all that oil doesn’t come out in the wash, high heat from the dryer could cause spontaneous combustion. Washing in cold water is part of the problem. “That cold water is locking that oil in that towel. Then you put it in a dryer and today’s dryers are super high heat dryers. You have the possibility of a spontaneous ignition occurring from the breakdown of that oil, ” said Cardwell.
August 31, 2011 Madison, WI – Spontaneous ignition blamed for southwest side restaurant fire. The Capital Times reported: “The investigation showed recently laundered towels (sic) were placed on a wooden table late Monday night,” Dahl said. “The towels were used for cleaning at the restaurant and contained cooking oil that can spontaneously ignite.” Dahl said even after washing, cooking oil residue remains in the cloth and can generate enough heat to ignite the fabric. “The laundered towels had been smoldering for several hours before the fire was discovered,” Dahl said. The restaurant was closed at the time of the fire. No injuries were reported. Dahl said oily rags, clothing and linens should be placed in a metal container with a self-closing lid to reduce the possibility of spontaneous ignition.
Protecting Your Business with Comprehensive Coverage
While following proper greasy rag handling procedures significantly reduces your fire risk, we understand that accidents can still happen in even the most well-managed kitchens. At Society Insurance, we’ve seen firsthand how quickly a small oversight can lead to significant property damage and business interruption.
Our restaurant insurance coverage is specifically designed with input from real restaurant owners who understand the unique challenges you face daily. We provide comprehensive protection that goes beyond standard policies, covering the specific risks that matter most to your operation.
For more on identifying and eliminating fire hazards in your restaurant, read our white paper. You’ll find tips on putting together a fire prevention plan and how proper duct cleaning can help safeguard your kitchen. Cover your restaurant from more industry risks with our restaurant coverage, built with the help of real restaurant owners like you. Get in touch with your local independent agent to learn what Society can do for your business.
