|
Factors Influencing Worker Safety in Grain Handling: An Advisory Panel Perspective
Elzerie Derry1, Gretchen A. Mosher1,*, Kingsly Ambrose2
Published in Journal of Agricultural Safety and Health 30(4): 163-180 (doi: 10.13031/jash.15915). Copyright 2024 American Society of Agricultural and Biological Engineers.
1 Department of Agricultural & Biosystems Engineering, Iowa State University, Ames, Iowa, USA.
2 Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, Indiana, USA.
* Correspondence: gamosher@iastate.edu
The authors have paid for open access for this article. This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License https://creative commons.org/licenses/by-nc-nd/4.0/
Submitted for review on 15 December 2023 as manuscript number JASH 15915; approved for publication as a Research Article by Associate Editor Dr. S. Dee Jepsen and Community Editor Dr. Michael Pate of the Ergonomics, Safety, & Health Community of ASABE on 23 July 2024.
Citation: Derry, E., Mosher, G. A., & Ambrose, K. (2024). Factors influencing worker safety in grain handling: An advisory panel perspective. J. Agric. Saf. Health, 30(4), 163-180. https://doi.org/10.13031/jash.15915
Highlights
Abstract. Out-of-condition grain has been identified as a primary causal factor in grain entrapments and engulfments. The quality of grain also has implications for grain dust explosions. Limited research has examined exactly which elements of grain condition influence worker safety in grain handling. This research project aimed to establish an advisory panel to examine and provide input on how elements of grain condition relate to worker safety risks in grain handling. A purposeful sampling technique was used to obtain a sample of grain handling and storage experts to function in an advisory role for the project. A primary aim of this research was to understand the problem further, provide input on tested variables, and guide educational and dissemination efforts. As is true for qualitative methodologies, those selected as part of the targeted sample cannot be generalized to other experts in the field of grain handling. The final sample contained six industry representatives, five academic professionals, and two insurance/regulatory professionals. Participants interviewed had varied expertise with grain-based safety events. Of those interviewed, 23% of participants had personal experience, 54% had bystander or investigator experience, and 23% had training experience. Semi-structured interviews were conducted to further understand the problem, provide input on important elements in safe grain handling, and guide educational and dissemination efforts. Interviews were analyzed with a primary objective to identify elements of grain condition that play a role in the incidence of grain entrapment, grain engulfments, or grain dust explosions. NVivo 14 was used to conduct a thematic analysis, and four overall themes were identified, which included challenges to worker safety in the grain handling industry, areas where improved communication is needed, grain quality indicators that may play a role in safety incidents, and available mitigation strategies. The themes are the opinions of the advisory panel and may not reflect those of the entire grain handling industry.
The agricultural industry is widely recognized as a hazardous industry for workers, based on the rate of total recordable cases of occupational injuries and illnesses and fatality rates (Bureau of Labor Statistics, 2023a,b). Data from 2022 indicated that farming, fishing, and forestry had the highest fatality rate at 23.5 fatalities per 100,000 full-time equivalent (FTE) workers, an increase from the 2021 fatality rate. Grain dust fires and explosions, hazardous gases, and hazards associated with entry into grain storage structures are some of the hazards associated with post-harvest grain storage and processing (Gorucu et al., 2022). Out-of-condition grain has been identified as the primary causal factor in grain entrapments and engulfment (Freeman et al., 1998; Kingman and Field, 2005). Additionally, the quality of grain also has implications for safety events such as grain dust explosions (Plumier et al., 2020). Managing the condition of grain has a critical impact on worker safety in grain handling. However, limited research has examined specific elements of grain condition that may influence worker safety in grain handling.
Entrapments and engulfments are among the most common fatal hazards associated with grain storage, with a mean of 35 entrapment cases per year since 2017 (Cheng et al., 2023; Issa et al., 2018). Typically, a person enters a grain bin to resolve a grain quality problem, address a grain flow problem caused by spoiled grain, clean out spoiled grain, or try and rescue a trapped person (Issa et al., 2018). Most workers are aware of the hazards associated with grain bin entry but may still choose to enter the grain bin to resolve a flow problem due to the need for productivity or the encouragement of their supervisor (Mosher et al., 2014). The agricultural industry is unique due to the large increase in workload during the planting season and harvest season, which creates a need for seasonal or temporary workers (Lehtola et al., 2008), who may not be adequately trained on safe handling protocols.
Grain dust explosions are another less common but severe hazard. From 1996 to 2005, an average of 10 grain dust explosions occurred each year (Schoeff, 2006). Grain dust, oxygen, confinement, mixing or dispersion, and an ignition source must all be present for a grain dust explosion to occur (Abbasi and Abbasi, 2007). Yet, in a grain handling environment, controlling hazards from ignition sources and effectively managing grain dust levels are challenging (Ambrose, 2021). During grain processing, grain dust is created and suspended in the air, which creates a potential for explosion (Zhao et al., 2020). Grain dust is flammable and has a low density, which allows it to form a dust cloud. Grain dust explosions not only lead to human injuries and fatalities but also cause extensive property damage (Ambrose, 2021). Grain dust prevention and control are thus important safety precautions in these processing facilities.
The aim of the project was to explore elements contributing to grain engulfment, grain entrapment, and grain explosion events by interviewing an expert panel of individuals from industry, academia, and governmental or regulatory areas. A primary outcome of the study was to improve understanding of the main contributors to grain safety hazards from the perspective of experts.
Materials and Methods
The paradigm/epistemological scope for this research study was constructionist. The focus of social constructionism was to discover how individuals and groups participate in the creation of their own perceived social reality (Crotty, 1998). The primary aim of the study was to understand the elements of grain condition that play a role in grain safety events. In this study, individuals were asked about their personal experiences and opinions on grain-based safety events they have been involved in or have experienced through their professional or personal lives. The theoretical perspective used in this study was critical inquiry. Critical inquiry begins when a researcher defines the meaning of the research question before beginning the study (Charmaz, 2016). In this case, the researcher usually pursues a cause and intends to educate or advocate in the public domain.
The methodology for this study was grounded in theory research, and the methods used to gather data were individual, semi-structured interviews. The methodology of this study was based on the research completed by Branstad-Spates (2023), who completed a qualitative study measuring stakeholder risk perceptions of mycotoxins in the Midwest grain and feed supply chain. A secondary aim of the study was to explain and produce additional knowledge on the contributing elements of grain condition that could lead to an increase in entrapment, engulfment, and grain dust explosion incidents.
A purposeful sampling approach was used to select 13 participants employed in academic, government, insurance, or grain industry sectors with a focus on grain handling and processing. Interview questions were used in this study because of the qualitative nature of the research. Interview questions were pilot-tested for validity and clarity with a small group of individuals who were similar to the final sample. The semi-structured interview structure helped participants explicitly describe their views and experiences (Creswell, 2014). It allowed participants to elaborate as they saw fit about their own experiences. The data collected were then analyzed in NVivo 14 (QSR International, Melbourne, Australia), and four themes were identified. The methodological flow of the study is shown in figure 1.
 |
| Figure 1. Methodological flow of the research study. |
Population, Sampling Frame, and Sample Design
A purposeful sampling technique was used to obtain a final sample of experts in the field of grain handling and storage. It is important to note that not all experts in the field were consulted, but the sample was diverse in terms of work and life experiences. At the time of recruitment, interviewees were emailed a brief description of the study, a participant information sheet, and a consent form for recording purposes. The list of potential participants to recruit was obtained through researchers at Iowa State University and from contacts and networks within the U.S. grain handling industry. The final sample was divided into three groups based on their specific area of expertise: insurance/regulatory professionals (IR), academic professionals (A), and industry representatives (I). The expertise and experience that each group brought to the problem also brought with it some level of bias in recruiting, but the aim of purposive sampling was to identify a sample with different perspectives and work/life experiences.
Insurance/regulatory professionals (IR) were individuals employed at insurance companies or government organizations, such as commodity or industry professional groups. Academic professionals (A) were individuals working in an academic institution who were involved with research, teaching, or extension. Industry representatives (I) were individuals employed in the grain handling industry with experience in grain safety, grain storage, or grain processing. Individuals were selected because of their national and regional leadership in grain handling safety hazards. IR, A, and I codes were used to identify participants. Individual names, contact information, affiliations, and other demographic information were kept confidential.
Recruitment
An email was sent to 19 individuals who had been identified by the research team as grain handling and storage experts in late April 2023. The email included a description of the study and interview process, a participant information sheet, and a consent form. Interested participants were asked to respond to the email with a date and time that worked for them between a 6-week time frame in May and June of 2023. Thirteen individuals responded to the initial email for a 68% response rate. The sample included 46% industry representatives, 38% who were academic professionals, and 15% who were classified as insurance/regulatory professionals.
Semi-Structured Interview Protocol Development
The semi-structured interview protocol was designed following the procedure used in research by Grover et al. (2016), identifying factors and challenges in adopting food safety preventative controls among small food facilities. The questions focused firstly on determining what industry participants were employed in, their level of experience, their level of education, what grains they mainly work with, and what safety training events they have attended. Secondly, participants were asked about their experiences with grain-related safety events and what elements of grain condition they believe may have contributed to the events described. Next, participants were asked about general perceptions regarding grain bin safety or major challenges facing the industry … finally, participants were asked whether a decision-making tool would improve decision-making and, if so, what aspects would make the decision-making tool most beneficial to ensure that it had a large impact on the safety of workers within the grain and feed industry. Prior to any interviews taking place, the semi-structured interview protocol was reviewed by academic personnel with knowledge of both grain handling and processing areas.
Participant Rights
Prior to reaching out to participants, the researcher obtained permission from the Institutional Review Board (IRB) (#23-076) (see Appendix C). The researcher obtained written consent to record the interview from all participants as well as oral consent from each participant during the interview. Participation in interviews was voluntary, and all identifying information was kept confidential. Participants could stop their involvement at any time. All participants consented to the recording process but were not required to answer any question that made them uncomfortable. When asked about personal experiences with grain-related safety events, interviewees were asked not to mention any names or other identifying information of individuals involved, injured, or killed.
Data Collection – Semi-Structured Interview Protocol
Interviews took place between May 2023 and June 2023 and were conducted using WebEx, which allowed for interviews to be recorded and transcribed. Interviews ranged in length from 7 minutes to 30 minutes. All interviews were conducted by one researcher to ensure all interviews followed the same structure and all interview participants provided information under a similar format. Interviews were transcribed using WebEx, using its automatic transcription feature. The transcript was then converted into a Microsoft Word document, and the researcher compared the transcript with the audio recording and corrected any errors or mis-transcription as needed. The process of comparing the transcribed text averaged between 30 and 40 minutes for each interview.
Data Storage and Processing
Transcripts of interviews, de-identified by codes assigned to each population group, were uploaded to a secure location provided by the university. Only research staff and the principal investigator had access to the password-secure “box” location. Transcripts were imported into the NVivo 14 software for analysis. Transcripts were coded, with differences and common elements identified, before themes were identified using NVivo 14. Nvivo 14 is a qualitative data analysis software that allows users to identify themes and draw conclusions from data. Content analysis used an inductive approach and was not based on an a priori coding approach (Kelle, 2007). Researchers reviewed the data and identified themes using an iterative process to facilitate a deeper understanding of the data (LeCompte, 2000).
Thematic Analysis
Qualitative research helps researchers to further understand the problem, explain quantitative data, and generate hypotheses (Tenny et al., 2022). Through qualitative research, participant experiences and perceptions were gathered and explored. Thematic analysis is the process of identifying, organizing, and offering insight into themes across data (Braun and Clarke, 2012). This thematic analysis allowed researchers to explore individual themes in interviews as well as overall themes of the research findings.
Results
Level of Experience with Grain-Based Safety Events
Participants were asked about their experience with grain-based safety events. The responses are shown in table 1 below, along with information on the percentage of each category of participant. Participant responses were coded as having personal experience, bystander or investigator experience, or training experience. Participants with personal experience had been either personally a victim of a grain-based safety event or personally involved in the rescue effort. Participants with bystander or investigator experience had either witnessed an event, observed a rescue effort, or been involved in an investigation of an event. Participants with training experience had never been involved in or experienced an event in their personal life or within their organization but held expertise obtained through textbooks or training related to grain-based safety events.
| Table 1. Participants and level of experience with grain-based safety events of the advisory panel. | |||
| Group Code and Participants | Personal Experience (23%) | Bystander or Investigator Experience (54%) | Training Experience (23%) |
| Industry (46%) | 1 | 1 | 0 |
| Academic (39%) | 0 | 2 | 3 |
| Insurance/Regulatory (46%) | 2 | 4 | 0 |
Thematic Analysis
Interview content was analyzed using NVivo 14. Eighteen individual themes were identified, and four overall themes were identified. The themes identified were challenges, communication, grain quality, and mitigation strategies. Overall themes and their codes can be found in figure 2.
 |
| Figure 2. Four themes and codes identified using thematic analysis. |
Challenges
Habituation
Participants were asked about what they believed to be challenges to worker safety in grain handling. Participants frequently brought up habituation or complacency as a challenge to worker safety. I1 stated, “I think complacency—nothing has happened here yet, what are the chances something is going to go catastrophically wrong?” as a common employee response to safety hazards. Participant A2 provided a similar view that workers become comfortable in their work environment, stating, “I think a big thing is to not take something that is familiar for granted. You know, you start to become comfortable with an environment that you work [in] all the time.” When discussing the topic, the A2 participant also stated, “I think those habits are easy to fall into …” A4 added “… on the other hand, people stay [at a company] 20 years, and they get used to it. They think nothing has happened in twenty years, then all of a sudden, they went in, they did not pay any attention, they got their hand or their foot stuck in a conveyor, and I know this as a fact.” The first theme aligns with previous findings (Thu et al., 1998; DeRoo and Rautiainen, 2000; Walker, 2010; Mosher, 2022) that describe and characterize the challenge of complacency.
High Employee Turnover
Challenges involving the historically high employee turnover rates seen in grain handling were frequently discussed by participants. When asked about turnover rates in industry, participant I4 stated, “… turnover rates are probably a big one ... when we have trouble finding people, [or] people don’t stay long, that means that you are constantly trying to retrain. When somebody is to the point that they really truly can be [working] and they know what they are looking for … then they are gone and you’re starting over.” Participant IR 4 also mentioned high turnover rates as an issue and highlighted that a new generation of employees is entering the workforce, “I would say obviously there is a high turnover rate and say with a new generation communication is critical.” Implied, but not said, was the belief that the “new” generation of employees may not have the agricultural knowledge and background that previous employees frequently brought to the job.
Lack of Resources
Participants frequently brought up a lack of resources as a challenge to worker safety, especially in the on-farm work environment. Participant A2 highlighted the on-farm work environment, stating, “… I think that is always going to be a challenge in on-farm storage because there is always something else to spend money on. Safety tools are not often things that people want to spend money on …” Participant I6 discussed the cost of keeping grain in condition: “The problem [of] working in an elevator plus seeing the rescue side of things looks to me like the cost of keeping the grain in management [is a factor]. If it’s a year where it seems like the prices are way down, it seems you put those 2 combinations together. It seems like that is [what happens in] our really bad years.” The integration of managing the quality of grain and worker safety implications is not new (Freeman et al., 1998; Kingman and Field, 2005), nor is it a concept unfamiliar to employees (Mosher et al., 2012), despite the clear safety hazard presented by out-of-condition grain.
Language Barrier
Challenges involving a language barrier were frequently discussed by participants; many workers do not speak English as their first language. When asked about the need for multilingual safety tools, participant A2 stated, “I think it most definitely needs to be multilingual. So, clearly, Spanish would need to be included in addition to English.” Participant IR2 pointed out that language barriers are more of an issue in the commercial grain industry as opposed to the on-farm environment. “Yeah, that is a problem, and not necessarily really on the farm side but definitely on the commodity grain elevator side, the operations side.” Participant A4 pointed out the research currently being done on the topic, “Yeah, language [are] barriers up to a point, but there has been a lot of push …”
Limited research has explored multilingual safety interventions, particularly in grain production (Farquhar et al., 2008; Ramos et al., 2021). However, it is well-documented that immigrant and foreign-born workers are often more vulnerable, employed in dangerous, dirty, and demanding jobs, including agriculture, and have fewer protections than other workers (Hernandez and Gabbard, 2018; Ramos et al., 2021). Limited English language proficiency may also have negative implications related to health and safety information, training, and perceptions of risk (Ramos et al., 2016).
Short on Time
Many panelists felt that employees may feel rushed to complete certain tasks because they might be short-staffed or short on time for some other reason. The grain handling industry is unique because of the large amount of grain being handled during harvest season within a narrow time window in the fall (Walker, 2010). Participant A3 stated, “I think that they get in too big of a hurry when they are unloading … particularly if they’ve hired someone to help move the grain, then everybody seems to be on the clock.” Participant A5 spoke on the importance of housekeeping activities to minimize grain dust in the production area to mitigate the risk of grain dust explosions: “… more importantly, there are not many people working there [at the grain elevator], so it is a huge volume of grain being handled and managed by very limited people. [For this reason], they don’t get the time to do maintenance and housekeeping activities.” Participant IR2 spoke on the speed of harvest and its effect on grain quality during storage: “More frequently … we rush through to get harvest started so quickly, and there is a lot of on-farm storage and even a lot of commercial grain storage that don’t have the ability to dry down grain [at the needed capacity]. So, they put wet grain away wet …”. Drying grain is the most common post-harvest process performed for long-term grain preservation (Bucklin et al., 2019), and storage and handling facilities for grain are designed with the assumption that grain flows freely. Yet, grain may not flow as expected if it has not been dried to a safe moisture for storage (Bucklin et al., 2019; Ileleji et al., 2017), resulting in worker safety hazards (Kingman and Field, 2005).
Speed of Grain Movement
When speaking on challenges to worker safety, many participants commented on how much faster grain is moved in the supply chain as compared to 10 or 20 years ago. Participant A2 mentioned that “… it is also the fact that we move grain a lot faster than we used to.” Two industry representatives also mentioned the issue with participant I5, stating, “My personal opinion is, I don’t think they [grain handling employees] understand the speed at which it happens.” Participant I6 added, “Over the years … the biggest changes that I have seen is the speed of grain movement.” Participants did not link the speed of grain movement to a specific safety hazard. The implied hazard is that engulfments and entrapments, when they occur, happen so quickly that they are difficult to prevent once an employee is in a compromising safety situation.
Communication
Awareness
A lack of communication was another challenge to worker safety discussed by participants. Many participants agreed that there is company awareness of the hazards surrounding grain bin safety, but they are not confident that those hazards are being effectively communicated to employees. Participant IR1 highlighted an increasing number of agricultural employees who are not from an agricultural background. This participant stated, "I think communications is the most important way of getting a message across. There may be a lot of [employees] that are, whether it be on a farm, whether it be a grain handling facility, that have not come from an agricultural background. By not having that type of background … they don’t have that experience, or they haven’t seen it.” Participant A1 also stated, “A lot of people are aware [of the hazards], but … I am not sure how well [those hazards] were communicated.” Participant A3 reiterated this idea by elaborating on lock-out-tag-out procedures: “… I think the awareness is there; it’s getting them to understand that there are alternatives to entering that grain when they have a problem. Convincing them to remember to shut off the augers before they enter [is also a challenge] …” Lockout and tagout violations are a common OSHA citation for commercial grain handling facilities (National Grain and Feed Association, 2018), but ultimately, the decision to enter a bin with bridged grain is an individual choice (Mosher et al., 2014). Several factors influence the employee’s decision, including peer or time pressure, workplace norms, employee competence, and workplace incentives (Mosher, 2022).
Company Culture
Participants discussed the role company culture plays in safety outcomes. A company or manager focused on the safety of their employees is more likely to point out unsafe actions or environments and correct their employees. Participant A2 highlighted the importance of creating a workplace culture that is focused on employee safety stating, “Hopefully you can institute a culture that will help you to put safety as a priority and try to help make sure that you are doing the right thing.” Participant I1 stated, “… A lot of it would depend on the manager or the operator themselves. How safety conscious they are, their background and [their] education and experience [all play a role].” Participant I2 discussed the management within a company as playing a large role in worker safety, “What I mean by management … what is the culture of the facility, what is the culture of the organization? … You are going to have some locations with different levels of management buy-in at particular locations. Do they really agree with the company culture that the senior management is really trying to instill in the organization?” The positive relationship between cultural factors such as trust and safety climate have been documented by researchers (Walker, 2010, Mosher et al., 2013; Ramos et al., 2021), but an in-depth examination of components of workplace culture would provide a clearer perspective on the relationship and how it could be utilized to enhance worker safety outcomes.
Training
Many participants felt there was a lack of training, not necessarily in industry but at the on-farm level. Participant A4 stated, “At the farm level, for sure, we need to train more people on safety.” Additionally, participant A5 also pointed out a lack of training as a challenge to worker safety. A number of panelists had experience providing grain rescue training to fire departments in their area and felt more needs to be done to provide training to emergency responders, especially in rural areas.
Grain Quality
High Moisture
When asked what factors may have been involved in the grain-based safety event, several participants mentioned high-moisture grains. Participant A2 stated, “Moisture is usually the big contributing factor when it comes to grain quality, and of course that impacts grain safety as well.” Participant A3 addressed grain that is clumping together as a big factor in engulfments and entrapments, stating, “Any condition that allows the grain to clump and then not free flow. So, along the edge of the bins, it could be a moisture issue; it could be a mold issue. In the center of the bins, it is almost always a moisture issue where it was either put in too wet or was not adequately dried, or there is a leak somewhere and something is causing the problem.” Storage of wet grain is a common occurrence, especially during harvest when drying capacity is limited (Bucklin et al., 2019).
Low Moisture
When asked what other factors may have been involved in the grain-based safety event, participants mentioned low moisture grain contributing to grain dust explosion incidents. Participant A5 stated, “If it is very dry [or] … if it is not stored very well, there’ll be lots of dust … handled along [with] the grains. So, that leads to a kind of generation of dust when doing anything …”. It is well known that grain handling environments generate large amounts of dust, yet limited empirical data have linked grain condition with the probability of a grain dust explosion (Sanghi and Ambrose, 2016).
Out-of-Condition Grain
When asked about what other factors may have been involved in grain-based safety events, many participants mentioned out-of-condition grain but did not elaborate further when prompted. Participants widely agreed that out-of-condition grain is primarily the reason workers feel a need to get in the bin in the first place. Participant A2 stated, “I mean, entering a bin is already a dangerous proposition, right? So generally, people enter into grain bins because the grain is out of condition. So, grain quality would be …. a primary issue associated with grain bin entrapments or other kinds of grain bin emergencies.” Participant I3 stated, “For entrapment, it is out of condition grain; I always say grain bin entry safety starts with quality management. If the quality of the grain is good, there won’t be an entrapment because why would you be there in the first place? My experience is that 85% of them are the reclaim holes; the center hole is plugged up, and somebody goes in with a rod to start poking, and they leave the equipment running when they do it. Another 10% are when the grain is hung up somehow at an angle and it avalanches on to them. If you limit those two things, it would get rid of most of them [in my opinion]. Bridging is another one …” Participant IR1 stated, “They are often not aware of … crusting, the bridging that can take place with the out-of-condition grain.” Issa et al. (2018) and Kingman and Field (2005) have documented the relationship between out-of-condition grain and engulfment and entrapment hazards. Although the safety hazards of out-of-condition grain are well known to both researchers and workers (Mosher et al., 2012), finding effective interventions to prevent entry into the grain bin has been more challenging (Mosher, 2022).
Toxin or Mold Presence
When discussing factors that may have been involved in a grain handling safety event, participants also highlighted mold or fungal growth as a contributing factor in grain handling safety events. Participant A2 stated, “… [entrapment or engulfment] is generally related to fungal growth.” Participant A3 noted, “It could be [due to a] mold issue.” On this topic, very little literature exists to support the knowledge shared by participants. While mold and fungal growth impact the quality, food safety, and the market price of grain, almost no laboratory or facility data have made a direct empirical connection between toxins or mold presence and grain entrapments and engulfments or grain dust explosions (Chen et al., 2020). The presence of mold and toxins do influence the condition of grain (McNeill, 2017), but these factors are rarely the only contributing factors.
Mitigation Strategies
Bin Coring
Participants frequently discussed bin coring as a method of prevention for entrapment and engulfment events. Bin coring is the process of removing fines from the grain mass after the grain has been placed in a storage bin. The removal of fines allows for an even airflow through the grain mass during aeration (McNeill, 2017). Participant A1 spoke about an incident he witnessed and the importance of removing fines from the grain mass, stating it was “a problem that they did not core it so the fines were not removed. When they were aerating, it bypassed that center core. … the reason to core the bin is to remove those fines so that you can allow airflow.” Participant A2 reiterated this point, saying, “[Generally, there is] some compaction of fines or something like that has occurred in the bin.” Participant IR2 added, “… [fines are present when a bin is] not cored properly, or not aerated properly.” Fines in grain storage prevent the effective aeration of grain, resulting in hotspots, which in turn could cause spoiled grain (McNeill, 2017). Bin coring cannot improve the condition of grain that is already out of condition or spoiled. Rather, it is part of the larger quality management plan for stored grain.
Dust Control
Participants also highlighted dust control as a method of prevention for grain dust explosions. Participant A4 stated, “… I recommend that people do all they can to prevent [explosions] by minimizing handling. There is a lot of dust accumulation, not good housekeeping, and not good handling equipment with preventative sensors.” A5 spoke about dry grain producing more dust in the production facility: “… [dry grain] will bring more dust. So, one [concern] is dust explosion, the other is inhalable dust … [which] carries mold spores and all those things.” Grain dust is part of handling and storing grain but also poses respiratory hazards, even in low concentrations (Purschwitz, 2017). Because of the ubiquitous nature of grain dust, housekeeping procedures to keep dust from accumulating are important, as is maintenance of equipment to minimize sparks, which mitigates explosion potential.
Grain Rescue Tube
Grain rescue tubes were frequently discussed by participants as an important tool for grain handlers and emergency responders to be familiar with and trained on. When available and correctly used, grain rescue tubes are effective in extracting a person from a grain mass, as long as the individual is still visible above the grain mass. Participant I4 pointed out that grain rescue tubes are expensive, but many organizations donate them to local fire departments and provide them with training. “… it is not cheap equipment … [for] … a volunteer fire department. I know our company has tried to make sure that local fire departments at least have rescue tubes, and there are a lot of organizations that distribute rescue tubes. You don’t want to have [to use] a rescue tube … but we have all read the news.” Participant I3 highlighted a possible lack in training: “Grain companies have bought tubes or had tubes donated to them and to fire departments. I do not think they have the proper training to know how to use those things, and the fire departments don’t either. That is the problem; you give them this tube, and they don’t even know how to use it.” Published evaluations of grain rescue tubes align with the participant viewpoints. As noted by Roberts et al. (2015), the grain rescue tube does not reduce the forces related to forcefully pulling an entrapped victim out of grain. Further, Roberts et al. (2015) noted that severe injuries could occur with rescue attempts with and without the grain rescue tube. Their primary recommendations were to update grain extrication training for emergency first responders. Further, the grain rescue tube is less of a preventive tool than a reactive tool. Meaning, it is only used in cases where a worker is already entrapped in grain.
Robotic Tools
Several participants highlighted a commercial tool known to be used to break up clumps of grain without workers having to enter the bin. These types of tools are a relatively new technology making its way into the industry, and the high costs of such tools were perceived as a barrier by participants. However, as the technology continues to be developed, there is a possibility that future cost barriers will lessen. Participant A2 stated, “I don’t know that it … can be fully implemented or fully effective, but there are some robots focused on [traveling] along the top of the grain and trying to break things up or going into a bin where there is a blockage and trying to break that up.” Participant IR2 mentioned robot technology as well: “It is a little robot; I think that is going to be phenomenal for the family farm; hopefully it will be priced to where people can afford it to buy one or two for their bins.” Limited empirical data exists on robotic products, but research measuring the impact and effectiveness of robotic tools to mitigate grain bin safety hazards is expected to increase.
Temperature Cables and Carbon Dioxide Monitoring
Participants highlighted temperature cables and carbon dioxide monitors as effective tools to monitor grain quality and ensure grain stays in condition. Participant I2 spoke about how important it is to make sure workers have access to these tools to make more informed safety and inventory management decisions, noting, “I would … put some preventative measures in place whether that is making sure that we have the right equipment for the people on the ground to do their job. [For example,] are there temperature cables in the bin, are there carbon dioxide monitors in the bin … are we using today's current technology to ensure the people we are putting in charge of millions of dollars of inventory … [have] the tools they need to successfully manage that inventory?” Participant A2 spoke about temperature cables not being able to detect some hot spots because they are placed too far apart in some bins. “We are often relying on temperature cables that are hanging in the bin, but they are … quite a distance away from each other, and there can be hotspots or out-of-condition grain in between where we are looking at …” Participant A2 pointed out that carbon dioxide monitors may be better suited to detect spoilage within a grain bin stating, “We are measuring primarily carbon dioxide at the top of the bin, but more sensing technology … will continue to improve our ability to understand when grain is beginning to go out of condition.” Participant A4 highlighted that this technology may not be as accessible for on-farm operations: “Going back to the grain entrapment, you know there are tools when you know your grain is out-of-condition, like temperature cables and carbon dioxide sensors. I mean, there is all this technology that on the farm level, depending on the farm, maybe there is an investment, but maybe not.”
London and Moore’s (2022) research aimed to understand farmer motivations for use of temperature probes in the grain bin. They found that hazard exposure did not significantly predict adoption of temperature probes. A better understanding of motivations behind the adoption of temperature and carbon dioxide monitoring, as well as motivations for adoption of robotic or AI technologies, represents an innovative direction in mitigation strategies.
Decision-Making Tool Input
During the interview, participants were asked if a decision-making tool focused on the connection between grain quality and worker safety would be beneficial. Eleven (85%) participants agreed that there is a need for a decision-making tool to communicate the impact of grain quality on worker safety to grain handling workers. The remaining 15% of participants remarked that it depended on what the tool looked like. There are a lot of safety materials available in the grain handling industry, and participants highlighted that any new tool needs to be easy to use and focus on grain quality management. Participants believed a decision-making tree format would be the most impactful and that there is a need for safety materials to be available in several different languages.
Further, Laberge et al. (2014) note that one recommendation for effectively reaching young workers with safety intervention suggests an approach involving learning paradigms (i.e., situated learning and communities of practice) rather than teaching paradigms (i.e., lectures, awareness campaigns, and behavioral modeling). A connection to the work context was a critical component of effective safety intervention programs. A decision tool could be created with these criteria in mind.
Discussion
This study utilized the input of a sample of experts in the grain handling and storage area. These individuals were chosen for participation in the project because of their expertise in grain handling from academic, practitioner, and regulatory perspectives. However, their opinions should not be seen as generalizable to the entire industry. Participants were contacted to participate in a brief interview about grain handling safety. Participants were categorized into three groups: insurance/regulatory professionals (IR), academic professionals (A), and industry representatives (I). Semi-structured interviews were conducted to identify participant experience with grain-related safety events and to identify elements of grain condition they believed to be contributing factors. Participants were also asked what they believed to be challenges to worker safety in grain handling. Thematic analysis was used to identify individual themes and overall themes.
Participants had varied expertise with grain-based safety events. Twenty-three percent of participants had personal experience and had been either personally a victim of a grain-based safety event or personally involved in the rescue effort. Fifty-four percent of participants had bystander or investigator experience and had either witnessed an event, witnessed a rescue effort, or been involved in an investigation of an event. The remaining twenty-three percent of participants had training experience and had not experienced an event in their personal life or within their organization but held expertise obtained through textbooks or training related to grain-based safety events.
The themes identified in this study were challenges to worker safety, a lack of communication, factors of grain quality that may influence worker safety, and mitigation strategies. Challenges to worker safety included habituation, high turnover rates, a lack of resources, a language barrier, being short on time or feeling rushed, and an increase in the speed of grain movement.
A lack of sensitivity to danger among workers in high-hazard environments poses a significant challenge to many industries, including agriculture (Mosher, 2022). Specifically, farm workers with more years of work experience are more likely to take risks and make unsafe decisions (Brison and Pickett, 1992). Further, factors other than safety may play a role in unsafe decision choices (Mosher et al., 2014). The finding confirms that safety concerns may not be enough to convince grain handlers to utilize and adopt mitigative technologies. Instead, the availability and access to information about technologies, as well as the behavioral dynamics, may also play a significant role (Cecchini et al., 2018; London and Moore, 2022).
A lack of communication was addressed by participants and focused on three key issues. According to the advisory panel, although workers may be aware of hazards, hazards may not be communicated to them in an effective manner. In these cases, company culture plays a large role in worker safety in an organization, and there is often a lack of relevant safety training for grain handling workers and rescue workers. Participation in safety training courses is associated with significant positive effects and a decrease in the number of injuries in the agricultural sector (Kim et al., 2017). Yet, it is important that training courses are offered in a language that workers understand, with material that is practical and easy to interpret, especially for workers who have little education. The importance of presenting hazard information that is specific to the work context, sometimes in several formats if needed, has also been highlighted (Laberge et al., 2014).
Participants were familiar with the connection between low grain quality, out-of-condition grain, and worker safety in grain handling. Participants were often not able to elaborate on exactly what factors of out-of-condition grain contributed to an increased likelihood of a safety incident. Some participants highlighted grain high in moisture as a contributing factor in grain engulfments and entrapments, while others identified mold or toxin presence as a contributing factor. Few participants had experience with grain dust explosions but mentioned extremely dry grain as a contributing factor. Overly dry grain has a higher potential to produce more fines, dust, and carry more mold spores, but no empirical data has linked dry grain to grain dust explosions (Amyotte and Eckhoff, 2009; TeBockhorst and Sheriddan, 2020).
Participants highlighted tools available to mitigate worker safety hazards in grain handling. Bin coring is the process of removing fines from the grain mass and ensuring that air can move evenly through the grain during aeration. Dust control through machinery maintenance and housekeeping procedures are effective strategies to minimize the risk of grain dust explosions. Grain rescue tubes are effective tools to rescue workers entrapped in grain when used correctly by trained personnel. Likewise, new robotic technologies show great promise in the future to address grain flow problems without the need for workers to enter the bin. Temperature cables and carbon dioxide monitors are effective tools to monitor grain quality during storage and can detect grain spoilage before flow problems may occur.
Limitations
The aim of this research was to understand the problem further, provide input on tested variables, and guide educational and dissemination efforts. Because of the limited size of the sample, the findings of this research cannot be generalized to other agricultural hazards or to the perceptions of all experts in grain handling safety. This study utilized the input of a targeted sample of 13 experts who were identified by their expertise in grain handling safety within industry, academic, and regulatory/insurance arenas in the Midwest region of the United States. Other areas may find the information informative, but the findings cannot be applied to other crop regions or climate zones, where experiences with grain hazards could differ substantially.
Future Work
Participants confirmed the concept of out-of-condition grain as a primary causal influence on worker safety in grain handling. Specifically, high-moisture grain, low-moisture grain, and toxin or mold presence were quality traits discussed. Future research in this area will seek to source and/or collect input data to construct two predictive models to characterize the relationship of traits and antecedents of grain condition. Firstly, a structural equation model (SEM) will be used to understand the empirical relationship between causal factors. Secondly, a stochastic model will be constructed to determine the predictive relationship of causal factors.
The project was unique because it focused on the impact of post-harvest grain quality, weather patterns, and seasonal data such as planting and harvest dates on the incidence of grain entrapment, engulfment, and grain dust explosions. Lastly, a tree-based decision-making tool, based on data sources and stakeholder inputs, to communicate findings to guide the grain handler on the management of out-of-condition grain will be a likely next step. Additional questions this research raised that warrant further investigation include how frequently grain-handling workers use existing mitigation tools available to them and the effectiveness of various methods of hazard communication to agricultural workers. These are areas that the advisory panel suggested could be improved.
Conclusions
This research established an advisory panel of grain handling and storage experts in the grain handling and processing industry and utilized the information they provided through semi-structured interviews to provide thematic areas to utilize for mathematical modeling. Insurance/regulatory professionals, academic professionals, or industry representatives identified four themes: challenges to worker safety in the grain handling industry, areas where improved communication is needed, grain quality indicators that may play a role in safety incidents, and available mitigation strategies. Participants also provided input on how research findings should be communicated to grain-handling workers. The research confirmed that out-of-condition grain is a primary causal factor in grain entrapment and engulfment as well as that the quality of grain has implications for grain dust explosions, at least in the minds of industry, academic, and insurance/regulatory stakeholders. The opinions of the advisory panel were based on academic, regulatory, or practitioner expertise, but their opinions should not be seen as generalizable to the entire grain industry. More information on the antecedents of grain quality are needed to improve causal factor identification and modeling. Future data collection and analysis should emphasize best practices for identification of how best to communicate the hazards and mitigation strategies to grain handlers on the farm and in commercial facilities.
Acknowledgments
Authors are grateful to those who were willing to participate in semi-structured interviews. This work was supported by USDA-NIFA project number 2022-68008-37105. The contents are solely the views of the authors and do not necessarily represent the official views of the USDA-NIFA.
References
Abbasi, T., & Abbasi, S. A. (2007). Dust explosions – Cases, causes, consequences, and control. J. Hazard. Mater., 140(1-2), 7-44. https://doi.org/10.1016/j.jhazmat.2006.11.007
Ambrose, R. P. (2021). Grain dust explosions: An omnipresent hazard. Resource Mag., 27(6), 7-9.
Amyotte, P. R., & Eckhoff, R. K. (2009). Dust explosion causation, prevention and mitigation: An overview. J. Chem. Health Saf., 17(1), 15-28. https://doi.org/10.1016/j.jchas.2009.05.002
Branstad-Spates, E. H. (2023). Integrated mycotoxin risk management strategies for grain handling and feed manufacturing industries. PhD diss. Iowa State University.
Braun, V., & Clarke, V. (2012). Thematic analysis. In P. M. H. Cooper (Ed.), APA handbook of research methods in psychology, Vol 2: Research designs: Quantitative, qualitative, neuropsychological, and biological (pp. 57-71). Washington, DC: American Psychological Association. https://doi.org/10.1037/13620-004
Brison, R. J., & Pickett, C. W. (1992). Non-fatal farm injuries on 117 eastern Ontario beef and dairy farms: A one-year study. Am. J. Ind. Med., 21(5), 623-636. https://doi.org/10.1002/ajim.4700210503
Bucklin, R., Thompson, S., Montross, M., & Abdel-Hadi, A. (2019). Chapter 9 - Grain storage systems design. In M. Kutz (Ed.), Handbook of farm, dairy and food machinery engineering (3rd ed., pp. 175-223). Academic Press. https://doi.org/10.1016/B978-0-12-814803-7.00009-9
Bureau of Labor Statistics. (2023a). Employer-reported workplace injuries and illnesses - 2021-2022. Retrieved from www.bls.gov/iif/nonfatal-injuries-and-illnesses-tables.htm
Bureau of Labor Statistics. (2023b). National census of fatal occupational injuries in 2022. Retrieved from www.bls.gov/iif/fatal-injuries-tables.htm
Cecchini, M., Bedini, R., Mosetti, D., Marino, S., & Stasi, S. (2018). Safety knowledge and changing behavior in agricultural workers: An assessment model applied in central Italy. Saf. Health Work, 9(2), 164-171. https://doi.org/10.1016/j.shaw.2017.07.009
Charmaz, K. (2017). The power of constructivist grounded theory for critical inquiry. Qual. Inq., 23(1), 34-45. https://doi.org/10.1177/1077800416657105
Chen, Z., Wassgren, C., & Ambrose, K. (2020). A review of grain kernel damage: Mechanisms, modeling, and testing procedures. Trans. ASABE, 63(2), 455-475. https://doi.org/10.13031/trans.13643
Cheng, Y. H., Nour, M. M., Field, W. E., Ambrose, R. P., & Sheldon, E. J. (2023). 2022 Summary of U.S. agricultural confined space-related injuries and fatalities. Agricultural Safety and Health Program Purdue University. Retrieved from https://www.purdue.edu/engineering/ABE/agconfinespaces/wp-content/uploads/2023/06/2022-Summary-of-US-Ag-Confined-Space-5-26-23.pdf
Creswell, J. W. (2014). Research design: Qualitative, quantitative and mixed methods approaches (4th ed.). Thousand Oaks, CA: SAGE Publ.
Crotty, M. (1998). The foundations of social research: Meaning and perspective in the research process (1st ed.). SAGE Publ.
DeRoo, L. A., & Rautiainen, R. H. (2000). A systematic review of farm safety interventions. Am. J. Prev. Med., 18(4), 51-62. https://doi.org/10.1016/S0749-3797(00)00141-0
Farquhar, S., Samples, J., Ventura, S., Davis, S., Abernathy, M., McCauley, L.,... Shadbeh, N. (2008). Promoting the occupational health of indigenous farmworkers. J. Immigr. Minor. Health, 10(3), 269-280. https://doi.org/10.1007/s10903-007-9075-5
Freeman, S. A., Kelley, K. W., Maier, D. E., & Field, W. E. (1998). Review of entrapments in bulk agricultural materials at commercial grain facilities. J. Saf. Res., 29(2), 123-134. https://doi.org/10.1016/S0022-4375(98)00008-5
Gorucu, S., Pate, M. L., Fetzer, L., & Brown, S. (2022). Farmers’ perceptions of grain bin entry hazards. J. Agric. Saf. Health, 28(1), 19-30. https://doi.org/10.13031/jash.14662
Grover, A. K., Chopra, S., & Mosher, G. A. (2016). Food safety modernization act: A quality management approach to identify and prioritize factors affecting adoption of preventive controls among small food facilities. Food Control, 66, 241-249. https://doi.org/10.1016/j.foodcont.2016.02.001
Hernandez, T., & Gabbard, S. (2018). Findings from the National Agricultural Workers Survey (NAWS) 2015-2016: A demographic and employment profile of United States farmworkers, Research Report No. 13. JBS International. Retrieved from https://www.dol.gov/sites/dolgov/files/ETA/naws/pdfs/NAWS_Research_Report_13.pdf
Ileleji, K., Maier, D. E., & Hellevang, K. (2017). Grain drying. In Grain drying, handling, and storage handbook, MWPS-13 (3rd ed., pp. 51-82). Ames, IA: Midwest Plan Service, Iowa State University.
Issa, S. F., Nour, M. M., & Field, W. E. (2018). Utilization and effectiveness of harnesses and lifelines in grain entrapment incidents: Preliminary analysis. J. Agric. Saf. Health, 24(2), 59-72. https://doi.org/10.13031/jash.12170
Kelle, U. (2007). The development of categories: Different approaches in grounded theory. In The sage handbook of grounded theory (pp. 191-213). https://doi.org/10.4135/9781848607941.n9
Kim, J.-S., Yoon, S.-Y., Cho, S.-Y., Kim, S.-K., Chung, I.-S., & Shin, H.-S. (2017). Effectiveness of participatory training for the promotion of work-related health and safety among Korean farmers. Ind. Health, 55(4), 391-401. https://doi.org/10.2486/indhealth.2017-0015
Kingman, D. M., & Field, W. E. (2005). Using fault tree analysis to identify contributing factors to engulfment in flowing grain in on-farm grain bins. J. Agric. Saf. Health, 11(4), 395-405. https://doi.org/10.13031/2013.19718
Laberge, M., MacEachen, E., & Calvet, B. (2014). Why are occupational health and safety training approaches not effective? Understanding young worker learning processes using an ergonomic lens. Saf. Sci., 68, 250-257. https://doi.org/10.1016/j.ssci.2014.04.012
LeCompte, M. D. (2000). Analyzing qualitative data. Theory Practice, 39(3), 146-154. https://doi.org/10.1207/s15430421tip3903_5
Lehtola, C. J., Brown, C. M., & Becker, W. J. (2008). Grain handling facilities - OSHA standard 1910.272. (ABE208). University of Florida, Institute of Food and Agricultural Sciences. Retrieved from http://ufdcimages.uflib.ufl.edu/IR/00/00/34/03/00001/OA11000.pdf
London, C., & Moore, J. M. (2022). Extended Technology Acceptance Model (TAM2) to understand decision making for grain bin hazards among Texas farmers. J. Agric. Saf. Health, 28(4), 229-243. https://doi.org/10.13031/jash.15135
McNeill, S. (2017). Grain storage. In Grain drying, handling, and storage handbook. MWPS-13 (3rd ed., pp. 83-101). Ames, IA: Midwest Plan Service, Iowa State University.
Mosher, G. A. (2022). Chapter 14 - Safety, human interactions, and decision-makings processes. In K. A. Rosentrater (Ed.), Storage of cereal grains and their products (5th ed., pp. 407-420). Woodhead Publ. https://doi.org/10.1016/B978-0-12-812758-2.00021-0
Mosher, G. A., Keren, N., Freeman, S. A., & Hurburgh, C. R. (2012). Management of safety and quality and the relationship with employee decisions in country grain elevators. J. Agric. Saf. Health, 18(3), 195-215. https://doi.org/10.13031/2013.41957
Mosher, G. A., Keren, N., Freeman, S. A., & Hurburgh, C. R. (2013). Measurement of worker perceptions of trust and safety climate in managers and supervisors at commercial grain elevators. J. Agric. Saf. Health, 19(2), 125-134. https://doi.org/10.13031/jash.19.9977
Mosher, G. A., Keren, N., Freeman, S. A., & Hurburgh, C. R. (2014). Development of a safety decision-making scenario to measure worker safety in agriculture. J. Agric. Saf. Health, 20(2), 91-107. https://doi.org/10.13031/jash.20.10358
National Grain and Feed Association. (2018). Grain and feed industry hazard information. Retrieved from https://www.osha.gov/sites/default/files/NGFA_2018.pdf
Plumier, B. M., Zhao, Y., Casada, M. E., Maghirang, R. G., & Ambrose, R. P. (2020). Dust content and adhesion characteristics of five corn samples. Trans. ASABE, 63(2), 495-499. https://doi.org/10.13031/trans.13747
Purschwitz, M. (2017). Safety and health in grain drying, handling, and storage. MWPS-13. In Grain drying, handling, and storage handbook (3rd ed., pp. 103-125). Ames, IA: Midwest Plan Service, Iowa State University.
Ramos, A. K., Carlo, G., Grant, K., Trinidad, N., & Correa, A. (2016). Stress, depression, and occupational injury among migrant farmworkers in Nebraska. Safety, 2(4), 23. https://doi.org/10.3390/safety2040023
Ramos, A. K., McGinley, M., & Carlo, G. (2021). The relations of workplace safety, perceived occupational stress, and adjustment among Latino/a immigrant cattle feedyard workers in the United States. Saf. Sci., 139, 105262. https://doi.org/10.1016/j.ssci.2021.105262
Roberts, M. J., Field, W. E., Maier, D. E., & Stroshine, R. L. (2015). Determination of entrapment victim extrication forces with and without use of a grain rescue tube. J. Agric. Saf. Health, 21(2), 71-83. https://doi.org/10.13031/jash.21.10150
Sanghi, A., & Kingsly Ambrose, R. P. (2016). Analysis of the effect of prevailing weather conditions on the occurrence of grain dust explosions. J. Agric. Saf. Health, 22(3), 187-197. https://doi.org/10.13031/jash.22.11654
Schoeff, R. W. (2006). Agricultural dust explosions in 2005. Manhattan, KS: Kansas State University Extension.
TeBockhorst, K., & Sheridan, C. (2020). Protect yourself from grain dust this fall. Ames, IA: Iowa State University Extension and Outreach, Integrated Crop Management. Retrieved from https://crops.extension.iastate.edu/blog/carolyn-sheriddan-kristina-tebockhorst/protect-yourself-grain-dust-fall
Tenny, S., Brannan, J. M., & Brannan, G. D. (2022). Qualitative study. StatPearls Publ. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK470395/
Thu, K. M., Pies, B., Roy, N., Von Essen, S., & Donham, K. (1998). A qualitative assessment of farmer responses to the certified safe farm concept in Iowa and Nebraska. J. Agric. Saf. Health, 4(3), 161-171. https://doi.org/10.13031/2013.15354
Walker, G. W. (2010). A safety counterculture challenge to a “safety climate”. Saf. Sci., 48(3), 333-341. https://doi.org/10.1016/j.ssci.2009.10.007
Zhao, J., Tang, G., Wang, Y., & Han, Y. (2020). Explosive property and combustion kinetics of grain dust with different particle sizes. Heliyon, 6(3). https://doi.org/10.1016/j.heliyon.2020.e03457