Oily Rags Safety

Spontaneous Combustion

Many materials are prone to spontaneous ignition such as linseed oil, oil-based paints and stains, varnishes and polyurethane, and paint thinners.

Oily rags have a long history of being a source of fire, because people are not aware that they have the ability to spontaneously combust and catch on fire. For a fire to exist, it needs heat, oxygen and fuel. Oily rags that get folded up or balled up, tossed on the floor or in the trash, have the danger of going through a process that starts with oxidation.

As the oil is drying on the rag, it produces heat, and air gets trapped in the folds or balled up portions. Heat and oxygen are combined in addition to the rag, which is usually made of combustible cloth that can become a source of fuel. Heat, oxygen and fuel are all that is needed to create a fire, which is why oily rags that are not disposed of properly can create a fire that people are not prepared for.

Prevention Practices Include:

• Placing oil-soaked rags in a container, which is equipped with a self-closing lid and listed/approved for such use.
• For somebody who uses oily rags on a daily or weekly basis, the oily rag should be placed in a listed oily waste container and emptied by a private contractor.
• For a less frequent user, oily rags should be stored in a small, airtight, non-combustible (such as metal) container with a tight-fitting lid. An old paint can is a good example. The rags should be completely covered with a solution of water and an oil breakdown detergent.
• Remove from buildings until it can be properly disposed of according to local environmental regulations.

For additional Loss Control guidance, please visit the Plan & Protect safety hub.

References:
NFPA Spontaneous Combustion or Chemical Reaction, Nov. 2011. NFPA Sept/Oct 2008 Fire Watch
Disposal of Oily Rags in Massachusetts
ISO Services, Inc. EngineeringAndSafety@ISO.com, OSHA 1926.252(e)