A pile of salt large enough to bury cars was cleaned up at the Morton Salt storage facility in Chicago. The salt spilled out of the building after a wall partially collapsed on December 30. The tons of salt trapped cars parked outside an Acura dealership. However, it caused no injuries and no extrications were necessary, reported ABC News (1.5.15).
Investigators said the salt was piled too high and this caused the wall to give way. A structural engineer was employed to check if the remaining structure was safe and supported. Crews will repair the plant’s wall.
Serious injuries, even death, can occur if people get entrapped or buried in a suffocating substance. When flowing, these materials can quickly submerge a person and cause suffocation. Death, in these cases, is the result of asphyxiation. Some materials known to have suffocated workers are gravel, coal, mud, grain, limestone, and sand.
Unstable material in storage bins can be dangerous for several reasons. The Occupational Safety and Health Administration warned that material being emptied from the bottom of storage bins can cause the surface to act like quicksand. This occurs as the flow of material forms a funnel-shaped path over the outlet with the material flow increasing toward the center of the funnel. The flow rate can become so great that is a worker is drawn into the flow path, making escape close to impossible.
Another hazardous condition is known as bridging. Bridging occurs when grain or other loose material clings to the sides of the container. When the material sticks, it can form a crust. This bridge of material may collapse without warning, burying workers standing below or caving in on top of a worker who steps on the bridge. Bridging also puts more pressure on the wall of the container, which may lead to a failure.
Incidents regarding loose materials in silos, bins or other large containers often result in multiple deaths because other workers attempt a rescue and become trapped, as well. Pulling out a worker who is trapped requires tremendous strength and one rescuer alone is not likely to be able to rescue a trapped person.
Under the Occupational Safety and Health Act of 1970, employers are responsible for providing safe and healthful workplaces for their employees. The deaths of workers who are entrapped and-or suffocated by collapsing material are preventable.
The ABC News story cited is “Morton Salt wall collapse mess cleared.”