Grain Storage: Rescuers Beware!
“Two teenagers (ages 14 and 19) were killed in a tragic incident involving a grain elevator in Illinois. Both young workers suffocated after being engulfed in a grain bin they had entered to help clear. A third young worker was pulled out of the storage bin alive, and was hospitalized after being trapped for 12 hours.”
Unfortunately, this is not a rare occurrence. Researchers at Purdue University documented 38 grain entrapments in 2009 alone. (*)
During recent months, OSHA has issued strong warnings concerning the dangers of grain storage facilities. This article is intended to remind emergency responders, in particular rural firefighters/rescuers, of the special hazards and other rescue considerations when called to the scene of a grain bin or silo accident.
In fact, OSHA 1910.272 Appendix A recommends that grain handling facility employers coordinate with local Fire Departments for the purpose of preplanning for emergencies. This standard (1910.272) also provides guidance to the facilities to help ensure a safe work environment for employees. Unfortunately, these accidents continue to happen.
So what are some of the hazards and considerations for responders when summoned to this type of rescue? First of all, as with any emergency situation, a thorough “size-up” must be made prior to committing any rescue personnel. Of course, any time confined spaces are involved, an understanding and evaluation of atmospheric hazards is critical to rescuer safety. Don’t allow your responders to become additional victims!
Depending on the product, atmospheric hazards may include airborne combustible dust, oxygen depletion, oxides of nitrogen, fumigants, and in some instances hydrogen sulfide. Therefore, one of the first considerations should be to ventilate the space in an attempt to eliminate the atmospheric hazard(s). If ventilation is not possible or effective, then appropriate PPE or intrinsically safe equipment must be employed. It is also critical for all machinery to be shut down and locked out/tagged out (LO/TO), especially discharge augers and any equipment that may cause vibration.
Let’s look at the scenario where a worker becomes engulfed while working on top of the grain. OSHA requires that workers walking on grain wear a body harness that is tied off with a restrain line unless it can be demonstrated that there is no engulfment hazard. It is also recommended that the worker be attached to a winch to aid in retrieval should they become engulfed. Unfortunately, there are many instances where these provisions are neglected and thus the worker becomes partially or fully engulfed with no immediate means of rescue.
Engulfment can occur due to a number of conditions. Walking down grain while the outlet auger is running is a recipe for disaster. It is shocking how quickly moving grain can engulf a worker. The funneling effect of moving grain is just something that a worker will not be able to outrun. It is forbidden for employees to walk down grain with the auger running and not using LO/TO.
A second situation that may lead to engulfment is breaking through “grain bridges.” Grain bridges develop when the top layer of grain becomes encrusted or freezes and the outlet of the grain below forms a pocket or void below the bridge. Employees and rescuers should always probe the surface of the grain with a rod to detect the presence of bridging to prevent this type of engulfment. Even wearing a harness and restraint line can lead to an engulfment if the bridge collapses while the individual is several feet laterally from their tie-off point.
A third way workers or rescuers may become engulfed is due to product avalanche. This occurs when product builds up on the walls of the bin and releases while the worker or rescuers are in the bin. For the responder that is called to a grain bin engulfment, one option of rescue is to cut outlet holes in several places on the outside wall of the structure just below the level of the victim. This will rapidly drain the product out and away from the victim. However, this may prove difficult if access to the required level of the bin is not readily available.
Another option is to remove the material from around the victim by using whatever means possible, including vacuum hoses, shovels, scoops, or buckets. Keep in mind that if rescuers enter the bin and are working on the surface, they also need to wear harnesses and restraint, preferably with a means of immediate retrieval. Avoid using self-retracting lifelines (SRL) as the quicksand effect of the grain may not cause a fast enough drop to activate the brake of the SRL.
To distribute the weight of the rescuer(s) and help prevent sinking into the product, consider using ladder sections placed on the surface of the grain. It is also imperative to use some type of cofferdam structure either manufactured specifically for this type of rescue or improvised using sheets of plywood or even backboards to prevent the material from filling back in around the victim as you dig them out. For a victim that is engulfed in a vertical or near vertical posture, a “rescue tube” (see video below) is a great option and comes in sections that are easily passed through the bin opening and can be assembled right at the victim’s location.
Typically, once a victim is buried mid-thigh to waist deep, they cannot escape without assistance. Fatalities from engulfment are usually suffocation due to blockage of the breathing passages with grain – even the partially engulfed victim may succumb to mechanical asphyxiation due to restricted movement of their chest walls and diaphragm.
In the case of cold grain engulfment, consider treating the victim for hypothermia as the material draws body warmth through conduction instead of convection. For the victim that is rescued after being engulfed in cold grain, continue resuscitation efforts even if they have no signs of life, similar to treating cold water drowning. In fact, OSHA reports of a near tragedy that occurred in February when a worker was trapped in soybeans up to his chest in 25 degree weather. Fortunately, he was ultimately rescued after a four-hour ordeal.
The bottom line for emergency responders… these types of rescues are time and labor intensive; it’s a slow and tedious process. What’s more, the probability of accessing the victims through elevated portals will often require the use of a ladder truck or high angle rope rescue once the victim is removed from the engulfment unless they are able to climb down on their own.
Also, take heed when performing the initial scene assessment. One of the first things to try to determine is “what happened to the victim?” (i.e., mechanism of injury). Stop and ask, “What do I need to do to keep this from happening to me?” Don’t end up in the same predicament as the victim – your personal safety and that of other responders is always paramount.
To summarize, rural firefighters/rescuers should be prepared by paying a visit to representative grain handling facilities in their response area. Become familiar with the types of hazards, equipment and machinery that may be encountered and the types of rescues that may be required. This preplanning may reveal the need for specialized training or equipment to help ensure that responders are capable, and most importantly adequately protected, when the emergency call for assistance is received.
(*) Excerpt from OSHA letter, dated August 4, 2010. Click here to read entire letter with additional incidents.