Hank Paul
Market Development Manager for EMEA
BS&B Pressure Safety Management B.V.

Combustible dust safety in the grain industry is an ongoing challenge that requires continuous attention and improvement. By understanding the hazards, adopting the best engineering practices as determined by advanced standards such as those developed by NFPA, and implementing effective safety management practices, the risks associated with combustible dust can be significantly reduced. Ultimately, the commitment to fostering a safe working environment protects employees, mitigates potential financial consequences and helps maintain a continuous and stable production environment.

INTRODUCTION

A typical wheat flour mill with a daily production capacity of 300 metric tonnes can feed up to 1.3 million people every day. The loss of such a facility would have a severe impact on any country and its inhabitants.

The UN’s Food & Agriculture Organization defined food security as follows: “When all people, at all times, have physical and economic access to sufficient safe and nutritious food that meets their dietary needs and food preferences for an active and healthy life.”

PRESENT SITUATION

At this moment, our planet houses more than 8 billion people, and roughly one in eight doesn’t have enough to eat. By 2050, the world is projected to accommodate around 10 billion humans, which will substantially increase the demand for food. Currently, more than one billion individuals lack sufficient food, and this situation is expected to worsen in the future. The 7 billion people who are receiving an appropriate level of nutrition depend upon a global network of grain industry activities that connect ‘farm to table’. Animal farming adds a further 24 billion mouths to feed which is also largely reliant upon the same network of grain industry activity. The journey from farm to table relies upon a global network of storage and processing facilities that manage the flow of seasonally produced raw grain to achieve a reliable source of nutritional ingredients every day of the year. 

An interruption to the storage and processing of grain quickly triggers the risk of a regional / national shortage of nutrition. The protection of the grain supply chain is a matter of strategic importance for countries, the industry, and both the human and animal consumers. Increasingly the storage and processing of grain products occurs at hub locations which serve potentially millions of consumers. The loss of a hub location can be devastating to the regional food supply chain. 

CURRENT & NEW CHALLENGES

 Throughout history, food production has been heavily impacted  by:

•  Conflicts – Local & International
• Trade Sanctions – Import & Export restrictions/ Tariffs & Quotas/ Embargos…
• Climate change – Extreme weather patterns/floods/drought…
• Variable agricultural productivity – Insufficient manures, fertilizers & pesticides as well as reduced yield due to over farming…

GRAIN STORAGE & PROCESSING

Human food & animal feed grain commodities remain the most suitable food source to feed the world’s growing population.They are stored in warehouses, silos, or bunkers to maintain quality and prevent spoilage before being processed into the form required to reach consumers.

Combustible dust risks introduce an additional concern in the grain industry. Fine particles of grains such as wheat, corn, and rice can create explosive environments within storage and processing equipment. When presented with an ignition source, these dust particles are the fuel that can support fires or explosions posing significant risks to workers, facilities, operations and jeopardizing food security.

Explosion safety in the grain storage, handling and processing industry requires a thorough understanding of combustible dust hazards, and preventive measures that can be implemented.

UNDERSTANDING COMBUSTIBLE DUST

Combustible dust is any solid material that can ignite and burn when dispersed in the air and ignited by a heat source. In the grain industry, dust can originate from various processes, including grinding, milling, conveying, and storage. The finer the dust, the more hazardous it is, as smaller particles can remain suspended in the air longer and ignite more easily.

The U.S. Occupational Safety and Health Administration (OSHA) defines combustible dust and outlines various materials that qualify, including organic substances such as grain particles. The National Fire Protection Association (NFPA) has developed standards, such as NFPA 61, that address the safety requirements related to combustible dust in agricultural and grain facilities.

IDENTIFYING THE HAZARDS

To effectively manage combustible dust risks, it is essential to identify potential sources and accumulation points within grain handling facilities:

1. Dust Generation Points: Focus on areas where mechanical processes generate dust, such as bucket elevators, conveyor systems, and grinding operations.

2. Accumulation Areas: Inspect surfaces where dust can settle, including floors, ledges, equipment, and ductwork. Dust accumulation can lead to fire hazards if not managed correctly.

3. Ignition Sources: Evaluate potential ignition sources within the facility, including electrical equipment, mechanical sparks, hot surfaces, or static electricity.

CONSEQUENCES OF DUST EXPLOSIONS

Dust explosions can be deadly and destroy/damage facilities leading to:

• Loss of life and property
• Supply chain disruptions
• Damage of company image & reputation
• Decrease in stakeholder confidence
• Increased insurance liability
• Food shortage → Diminished food security

SAFETY MANAGEMENT PRACTICES

To mitigate combustible dust risks in the grain industry, implementation of  the following management practices is recommended:

1. Process Controls:

Dust Management Systems: Invest in effective dust collection systems to capture dust at the source. Regular maintenance of these systems is critical to ensure continuous operation.

2. Housekeeping:

Establish a regular housekeeping program to maintain cleanliness and minimize dust accumulation in work areas. Use appropriate cleaning methods, such as vacuuming, rather than sweeping, to prevent dust dispersion.

3. Employee Training:

Conduct regular training sessions for employees on the hazards of combustible dust, safe work practices, and emergency response protocols. Ensure that employees understand the significance of reporting dust accumulation and potential hazards.

4. Emergency Preparedness:

 Develop and implement emergency response plans that include procedures for dust ignition, fire, or explosion incidents. Conduct drills to familiarize employees with emergency procedures.

5. Monitoring and Continuous Improvement:

Implement a monitoring program to regularly assess and analyze dust levels in various areas of the facility. Utilize feedback from inspections and employee observations to continuously improve safety practices.

6. Process Safety

• Explosion Venting: Install explosion vents to safely relieve pressure in the event of an explosion, directing the force away from personnel and structures. Note that the flame ball released must have a safe discharge path.
• Explosion Suppression & Isolation: This extinguishing technique mitigates an explosion event by responding to the earliest stage of combustion, preventing the full deflagration from developing. Additionally, Isolation is always important to arrest the flame & pressure propagation between two pieces of process equipment.
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RISK ASSESSMENT

Conducting a risk assessment is crucial for understanding the potential impact of combustible dust in a facility. A thorough risk assessment includes:

• Evaluating dust sample sizes and characteristics.
• Identifying ignition sources and their likelihood.
• Assessing the operational environment and working conditions.
• This assessment helps prioritize safety measures tailored to specific facility needs.

RISK MANAGEMENT

OSHA regulations and NFPA guidelines provide a tried and tested path to optimization of safety in the grain industry. Key requirements may include:

• Hazard Communication: Facilities must communicate dust hazards to employees through safety data sheets and training programs.
• Dust Control Measures: Implementing engineering controls, such as dust collection systems, maintains dust levels below thresholds.
  
• Regular Inspections: Conducting routine inspections and maintenance of equipment to prevent dust accumulation and ensure proper operation.
  
• Management of Change: whenever a process is altered, the risk may change which requires a new assessment of the prevention strategies. 
  

RECENT EXPLOSION INCIDENTS AND WHAT CAN BE LEARNT FROM THEM

Reviewing incidents in the recent past in the grain industry can provide valuable insights into effective safety practices:

1. Kocaeli Grain Terminal - Türkiye: In August 2023, a devastating explosion at the Derince Port terminal, highlights the hazards of combustible dust. The incident resulted in fatalities and complete facility damage, emphasizing the need for strict adherence to dust control and safety measures in all industries handling combustible materials.

2. Pasta Factory Hendek - Türkiye: In September 2024,  another massive explosion occurred at a pasta production plant in Sakarya province. The company involved is a key player in the Turkish market. Here again, there were multiple fatalities, and the factory was destroyed due to a dust explosion. Investigations are ongoing.

These cases underscore the importance of adopting a proactive and comprehensive approach to dust safety across grain storage, handling and processing facilities.

CONCLUSION

Combustible dust safety in the grain industry is an ongoing challenge that requires continuous attention and improvement. By understanding the hazards, adopting the best engineering practices as determined by advanced standards such as those developed by NFPA, and implementing effective safety management practices, the risks associated with combustible dust can be significantly reduced. Ultimately, the commitment to fostering a safe working environment protects employees, mitigates potential financial consequences and helps maintain a continuous and stable production environment. All of these factors contribute to achieving global food security.