For decades the grain handling industry has struggled with the catastrophic effects of dust explosions at facilities throughout the United States. However, the industry has made tremendous strides to make the workplace safer upon the harsh backdrop that the industry faced as of the 1970s. Chart 1, issued by the United States Department of Labor (DOL) as of 2011, establishes how far the industry has come in the past 35 years.
The stark reality that forced the grain handling industry to seriously address these catastrophic events can be traced back to December of 1977 when five separate elevator explosions occurred in that month alone, resulting in 59 individuals' deaths and injury to 48 additional workers.
Even prior to that time, the DOL recognized the need to examine this issue and already had begun gathering and evaluating information on dust explosions. In order to understand and address the reasons as to why these dust explosions were occurring, the USDA and the DOL endorsed the creation the Panel on the Causes and Prevention of Grain Elevator and Mill Explosions. Simultaneously, the National Institute of Occupational Safety and Health (NIOSH) conducted its own investigation to examine the various causes of grain dust explosions.
Out of those studies, the Occupational Safety and Health Administration (OSHA) issued a proposed standard in 1984 to address issues such as preventive maintenance, housekeeping, and the prevention of explosions by attempting to control dust accumulations and ignition sources. Then, in March of 1988, OSHA issued its standard, 29 Code of Federal Regulations (CFR) 1910.272, commonly referred to in the industry as the “Grain Handling Standard.”1
As the explosion statistics chart clearly establishes, the industry has made tremendous strides in preventing dust explosions. Unfortunately, when even one dust explosion event occurs, the damage and/or devastation may result in severe injuries and/or loss of lives as was evidenced in the tragic event which occurred at a grain facility in Atchison, KS in October of 2011.
This article outlines three steps that can be taken by grain handling facilities to prevent a dust explosion:
- Proper housekeeping of the facility
- Proper maintenance of equipment
- Proper training of elevator personnel to ensure that employees are performing their jobs with an eye toward safety and dust explosion prevention
Elements of a dust explosion
A dust explosion can occur if the following five elements are met2:
- Grain dust must be present
- An ignition source must be present
- Oxygen must be present in a concentration to sustain rapid combustion
- The grain dust must be well mixed with the oxygen at a concentration above the lower explosive limit
- Ignition must occur in an enclosed space
If the dust or the ignition source is removed, obviously the explosion cannot occur, which is why there is such a strong emphasis for proper housekeeping (removal of dust) and proper maintenance of equipment (elimination of a potential ignition source) by OSHA, all as outlined in the Grain Handling Standard.
When a dust explosion occurs, there is a significant likelihood of a lawsuit or lawsuits being initiated by: (1) entities attempting to recover for property damage or economic losses, or (2) by individuals who have been injured, or (3) families who have lost a loved one.
In my involvement in these suits, I have made the following observations regarding poor housekeeping measures at facilities:
- Boot pits full of dust, particularly in older facilities
- Dust blown down into pit areas and not properly or timely removed
- Dust leaking from overhead ducting
- Conveying equipment with layers of dust laying on top of the equipment
- Galleries ignored from regular housekeeping measures