In today’s episode of the Dust Safety Science podcast, we’re doing an incident update on a 2021 seed preparation facility explosion in Silverton, Oregon. We’ll also discuss why incident updates are important and answer the following questions:
- What was known beforehand about this specific incident in Silverton, Oregon?
- How did the incident leave us with unanswered questions?
- What was the outcome of our enhanced incident research?
- In light of this additional investigation work, what did we learn? And in what ways can it be applied in the future?
Why Are Incident Updates Important?
Our combustible dust incident database is our measuring stick for reporting, generating lessons learned, and understanding challenges related to combustible dust fires and explosions. We use it to measure our progress toward our “Road to Zero” mission – to have zero fatalities worldwide by 2038.
In addition, we’ve been asking ourselves how we can make this information more valuable to the community. The question is how do we generate more information that can be used to improve safety procedures and drive government policy? What can we do to increase the work we’ve been doing?
This episode is partly based on a project we did at Dalhousie University called View Dust. View stands for Verify, Improve and Expand on Web-based dust explosion incident reporting. This was a pilot project we did with Dalhousie a few years ago, with Dr. Paul Amyotte and a student, Ahmed Daud.
In order to verify incidents that are reported through this web-based reporting system, we tried to develop protocols and procedures for ensuring that the information available to the community is as accurate as possible by digging deeper into the technical aspects and expanding on that information.
This work led to the development of a protocol to track these incidents over time, so we can understand the long-term impacts on the community and the company involved. We started doing this with the larger loss incidents that do have injuries and fatalities- tracking them over time and improving the information we have about them. This includes:
- Reaching out to fire departments
- Trying to get access to investigation reports
- Doing Freedom of Information Act requests
- Reaching out to point of contacts in other countries
These incidents are extremely traumatic to the victims, survivors, families, companies, owners, first responders, and local government jurisdictions. They can involve loss of life, loss of limb, loss of product, loss of jobs, and lots of other mental, physical, and difficult challenges. For us, it’s critical to figure out what caused the set of circumstances that occurred on that particular day, in order to prevent similar incidents from happening again.
What Happened During This Incident in Silverton, Oregon?
On March 23rd, 2021, local news stations reported a dust explosion at a seed cleaning and crop preparation services company in Silverton, Oregon. First responders were called out at 9:00 a.m.. Seeing the second floor engulfed in flames, they quickly upgraded the fire to a three-alarm response. One employee was found deceased on the second floor of the building, while another worker was taken to the hospital for smoke inhalation injuries.
That was really all the information available from local news sources. They did mention that it was a dust explosion, although there was a large fire component. There are several questions about the incident that remain to be answered in terms of this initial reporting, particularly whether it was really a fire explosion.
Some photos show quite a bit of destruction on the second floor of this seed cleaning facility. In these cases, it is often difficult to tell whether the roof collapsed due to a large fire, the roof blew off due to an explosion, or both, as is usually the case. What type of equipment or process might have caused the explosion? When the explosion occurred, what operations were taking place? For those who do dust hazard analysis, these are really good indications of how a similar incident can be prevented in the future.
When we retrieved the investigation report, it stated that the incident happened in the second/third storey areas of the seed cleaner part of the facility. The deceased was found on top of fall-down material on the ground floor, which suggests that he’d been on the second or third floor when the incident originally happened, and then fell down.
He had been on the third floor, removing a tarp that covered seed waste in a chaff bunker. This bunker funnelled waste seed and chaff to a conveyor, which took it outside. They do note that the seed cleaner was not in operation and they were actually in the process of dismantling that bunker when the explosion happened.
Additional details:
- The power to the seed clean conveyors was turned off. Conveyors were locked and tagged out when the explosion happened.
- The owner was able to show video surveillance with the ground floor directly under where the deceased was working when the incident happened. Dust could be observed coming from the doorway of the bunker. There are periods of light dust, no dust and then heavy dust coming from the doorway. The video showed four very quick flame bursts coming from the door area. Approximately 58 seconds after the flame bursts, rapid expansion associated with extremely vigorous over-release of energy occurred.
Further, they note that the bunker doorway area had extreme charring on the top and bottom of heavy timbers, indicative of slow-burning that may have started hours earlier. Before the incident, employees were in the bunker room on the ground floor, dismantling it. The remains of tools and a ladder were discovered.
The incident was reported as accidental and listed with a total loss of $1.4 million, but the biggest tragedy is the loss of life. This is why we collect enhanced incident data- for knowledge and training purposes and prevent such an incident from happening again.
Challenge #1: Awareness and Training
Shutting off the equipment was a good step in terms of awareness and training – if they did that on purpose before dismantling the equipment and cleaning up the raw materials. It is difficult to say at this stage what level of understanding the people on the ground had of combustible hazards.
In this case, combustible dust safety training at a very high level could have been very helpful, since dispersed dust near an ignition source can cause a flash fire and explosion, or vice versa. It’s highly likely that such awareness could have prevented the explosion from happening.
Challenge #2: Requirements for Dust Hazard Analysis
There is no evidence that a DHA had been completed at this site before the incident occurred, but they certainly did have at least three sides to the explosion pentagon: combustible dust, oxidizing medium, and confinement. As a result of cleanup activities, they experienced dispersion, and the ignition source may have been the slow burning of wood in the structure.
It is certainly possible that a DHA would have identified the need to clean up material in this area of the seed cleaner.
There is also a possibility that an explosion elsewhere in the system might have caused this incident. In any case, even if there wasn’t any smouldering combustion or slow charring nearby, if the explosion occurred in the bucket elevator or the dust collector, it could have propagated into the seed cleaning room, causing a secondary explosion.
So would a DHA have indicated challenges with the facility inside equipment and outside of equipment? Probably. A risk ranking matrix or a well-developed implementation plan should have identified the highest risks and what needed to be tackled first.
Challenge #3: Challenges with Small Facilities
With small facilities, concerns are often expressed about the cost involved in implementing DHA requirements and training. However, an explosion will be even more expensive to deal with.
It is not cost prohibitive to perform a DHA in a small facility. If you hire a worthwhile provider to do your dust hazard analysis, they will provide you with an implementation plan as part of the analysis. You can also work towards those larger capital expenditures over time if you start by identifying low-cost actions that you can take.
Conclusion
The Silverton, Oregon incident was a real tragedy. But by understanding what happened, you can take the lessons learned and use them to prevent another, similar incident. The goal is to keep improving- it’s the only way forward.
Resources mentioned
Dust Safety Science
Combustible Dust Incident Database
Dust Safety Science Podcast
Questions from the Community
Dust Safety Academy
Dust Safety Professionals
Dust Safety Share
Incidents
Dust Explosion at Crop Preparation Plant Kills One and Injures Another
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