Staying Safe in the grain bin

Grain storage bins pose serious hazards for farmworkers and have prompted an extensive list of Occupational Safety and Health Administration (OSHA) requirements for running and/or working around grain bins and silos.

Why such an abundance of caution?

Explosion

Harvested grain is extremely dusty, and grain dust in a confined space can create a hazard. If the confined dust becomes airborne inside the storage facility or other confined area and meets a source of heat — a static charge or a bearing burning out in an elevator’s machinery, for example — the dust can ignite, producing a chain reaction of explosions that can damage or even blow apart the vessel, and injure or kill someone.

According to an annual survey published by Purdue University, on average, grain bin explosions only happen 8.6 times a year. However, when these incidents do occur, they can be extremely costly and endanger multiple lives. For example, one 2014 explosion, which occurred at an Ohio facility where grain was being loaded onto a freight train, severely damaged three connected silos and a number of rail cars, and injured six workers. Cleanup involved vacuuming up roughly a million bushels of grain, and rebuilding took months.

Fire

If mold begins to grow in stored grain, it can envelop the grain kernels, binding them together into an ever-growing mass. Mold spores feeding on the grain’s starches and oils produce water, carbon-dioxide, and heat, creating a hot spot in the center of the mass. If insects have infested the grain, this heating process can accelerate. As long as oxygen can’t get to this heated mass, it may remain inert. But that can quickly change if the grain is disturbed, as it is when it’s unloaded from storage.

Engulfment

Shifting grain can behave like quicksand, sucking in and entrapping farm workers and suffocating them — literally drowning them in grain. This is the leading cause of confined-space death in agriculture. According to research compiled in the Purdue Agricultural Confined Spaces Incident Database (PACSID), there were 2,429 cases documented between 1962 and 2024, with approximately 58 percent of documented cases reported as fatal. In 2024, the most recent year for which statistics were available, grain entrapments increased by 25 percent over the previous year.

Engulfment most often happens when a worker without safety equipment enters the top of a storage structure to solve a problem, such as a clog. Meanwhile, below, another worker starts a grain auger to empty the vessel. The entire mass of grain begins to shift, making it extremely difficult for the worker at the top of the bin to get out. In 4 seconds, an adult can be entrapped and unable to get free, and in less than 20 seconds the worker may be completely buried. If things reach this stage, it can take a literal ton of force to extricate them. Given these grim figures, it’s easy to understand why so many of these cases end in loss of life.
Engulfment can also occur when the process of emptying the bin has been stopped and started several times, causing a “grain bridge” to form. This occurs when mold or freezing has caused the top layer of grain to form a deceptively hard, thick crust. But the bridge is likely to collapse, dropping a worker into the loose grain below where they can suffocate.
Workers can also be imperiled when damp or moldy grain has formed steep columns against a bin wall. When a worker tries to dislodge the grain, they can be buried in a grain avalanche.

For more information about farm safety, visit our collection of farm safety tips and resources. Learn more about best safety practices for working in and around grain bins, and find more sources for information, in Grinnell Mutual’s downloadable “Worker Entry into Grain Storage Bins” loss control bulletin.

You can also see a trailer of the independent film “Silo,” an affecting story about a frightening grain bin experience, and learn how to get a DVD or host a screening in your community.

Sources: Haag Engineering and Consulting, Kansas State University Department of Grain Science; Oklahoma State University Extension Service; Successful Farming, Feb.19, 2026

The information included here was obtained from sources believed to be reliable, however Grinnell Mutual Reinsurance Company, SI, and its employees make no guarantee of results and assume no liability in connection with any training, materials, suggestions, or information provided. It is the user’s responsibility to confirm compliance with any applicable local, state, or federal regulations. Information obtained from or via Grinnell Mutual Reinsurance Company, SI, should not be used as the basis for legal advice and should be confirmed with alternative sources.

7/2026