Safex Newsletter No.83 November 2025

As per usual we start the Newsletter with a safety message from an industry leader, this time it is from Mauro Neves, the CEO of Dyno Nobel, John Rathbun, our chairman, hosted a successful meeting with the CEOs from our industry on 28 October, aiming to foster substantial support for SAFEX from industry leaders. This gathering underscore our commitment to strengthening strategic alliances and advancing our core mission under challenging circumstances. The primary objective is to secure widespread backing and collaboration to ensure the successful promotion and development of SAFEX initiatives, reflecting our dedication to industry growth and innovation.

Under the leadership of Juan Andres Errazuriz, ENAEX sponsored our ninth webinar focused on "Lessons Learned During Burning Ground Activities." This topic is highly relevant to safety practices across our industry. Participants are encouraged to review the Argyle incident detailed on our website, which highlights the hazards associated with burning ground operations. The incident underscores the importance of implementing effective mitigation strategies to prevent similar occurrences. Emphasizing safety protocols and hazard awareness is essential to ensure the well-being of personnel and the integrity of operations during such activities.

Andy Begg and Paul Siqueira have published an authoritative awareness document on Safety Management Systems. This comprehensive resource is now available on our website, designed to serve as a valuable reference for all stakeholders. It encourages active engagement and input from users, fostering a collaborative approach to safety management practices within the organization.

SAFEX received two articles on dust extraction very much complimenting each other:

Energetic Dust control: Lessons from Recent Incidents by Joao Roorda and Nadia Engler

Dust Generation and Control in the Explosives Industry by Paulo Siqueira.

Bob Woolley emphasizes the importance of establishing a solid foundation in our hazardous industry. Proper understanding and implementation of fundamental safety protocols are crucial, as neglecting these principles can lead to severe consequences, including threats to human life and infrastructure integrity. Ensuring that safety measures are correctly applied not only mitigates risks but also promotes a culture of safety and responsibility within the industry.

At Dyno Nobel, safety leadership is not just a role—it’s a responsibility woven into the fabric of how the Company Operates. There behavioural safety journey has evolved from foundational programs like SafeTEAMS and concepts of SafeGROUND to the launch of SafeLEADERS, a comprehensive leadership development initiative designed to embed safety into every decision, conversation, and action.The article on this was presented by Diana Gianne from Dyno Nobel.

Following numerous years of dedicated service, several esteemed Expert Panel Members elected to dedicate their retirement to personal pursuits. This transition posed a significant challenge to SAFEX, as it resulted in the loss of valuable industry experience accumulated over the years. In response, Andy Begg initiated a strategic recruitment campaign to attract new talent. We are pleased to introduce the new members who have joined our Expert Panel. Comprehensive details about these individuals are also available on our official website, reflecting our ongoing commitment to maintaining a highly qualified and experienced panel to support industry excellence.

It is with profound sadness that we acknowledge the passing of Mervyn Traut, a highly respected member of our industry community. Mervyn was renowned for his mentorship, unwavering support, and dedicated assistance to SAFEX and its members over many years. His contributions have left a lasting impact, and he will be sincerely missed. Below is a tribute written by Dr. Boet Coezee, honoring his exceptional life and legacy.

Finally, I am pleased to share a flyer to inform members about the upcoming Third International Explosives Conference scheduled to take place in Cardiff, Wales, in June 2026. For comprehensive details and registration information, please visit the official conference website.

Dust Generation and Control in the Explosives Industry

By Paulo Siqueira

Dust generation and accumulation in explosives manufacturing plants poses a serious risk, as many explosive materials are highly sensitive to FISH - Friction, Impact, Electrostatic discharge, and Heat.

Over the years, numerous incidents have been linked to inadequate dust control, resulting in fires, explosions, and worker injuries and fatalities. Effective dust extraction systems and operating practices are essential to minimize these hazardous conditions, ensuring that fine particles are safely collected and removed from work areas.

To be effective in managing explosives dusts it is necessary to identify hazards, analyse the risks and adopt controls to prevent incidents and minimize consequences.

1. Identification of sources of dust generation

Dust is generated at multiple stages of explosives manufacturing, particularly during material handling, processing, and finishing operations. Common sources include:

  • Powder handling: transferring, mixing, sieving, pouring and packaging of fine explosive powders.
  • Milling and grinding – reduction of particle size.
  • Drying process – evaporation of solvents, blowing/exhausting air, leaving behind fine residues.
  • Screening: separation of different particle sizes.
  • Handling of waste and scrap materials: cleaning working stations, equipment, collection and disposal of explosive residues.
  • Manual operations: sweeping, cleaning, and maintenance activities that disturb settled dust.

2. Potential Sources for dust generation

  • Lead Azide: warm air flowing over powder trays in drying operation, dry screening operations, transferring lead azide from trays to containers.
  • Detonators press: pouring Lead Azide and PETN into hoppers; press movement spreading fine particles of explosives.
  • PETN: drying PETN, dry sieving, transferring dry PETN from bags to buckets, pouring dry bulk PETN into smaller containers.
  • Detonating Cord: movement of spinning machines spreading PETN dust, feeding PETN hoppers.
  • Delay Compositions: moving dry delay compositions in trays, pouring in small pots, pouring in caps, feeding hoppers.
  • Delay elements: feeding powder in delay elements, cutting lead drawn delay tubes
  • Shock tube: HMX /AL handling, pouring, feeding the explosive hopper above the extruder, HMX powder in the cutting stage on coiling machines.
  • Black powder: milling, safety fuse spinning machines,
  • Pentolite: TNT and PETN handling, feeding kettles, cleaning of boosters.

3. Explosives dust accumulating and associated hazards

Accumulation of explosive dust presents multiple hazards, including:

  • Fire and explosion risks: fine dust particles can become airborne and form explosive atmospheres.
  • Electrostatic discharge: dust particles rub against each other, or other surfaces may create an imbalance of electric charge.
  • Health risks: prolonged exposure to airborne dust can affect respiratory health, skin and blood conditions.

4. Ignition sources for Explosives Dust on Workstations (FISH)

Friction and Impact

  • Tools (e.g., hammers, screwdrivers) rubbing or striking surfaces.
  • Equipment parts rubbing due to misalignment or wear
  • Dropping heavy objects on dusty surfaces.

Sparks. Electrostatic Discharge and Electrical Sources

  • Static buildup on plastic, synthetic clothing
  • Operators not grounded
  • Movement of dust through non-conductive ducts or surfaces.
  • Faulty wiring, loose connections, or damaged cables
  • Switching relays, motors, or control panels producing arcs
  • Sparks from portable electrical tools (e.g., drills, grinders)
  • Use of inappropriate tools
  • Lack of maintenance in grounding systems
  • Use of pneumatic tools or Compressed air generating or generating dust clouds and exposing them to a hidden ignition source.

Heat. Open Flames or Hot Surfaces

  • Hot work, soldering, welding, or cutting
  • Hot process equipment (heaters, dryers, stoves)
  • Overheated motors, transformers, electrical circuits
  • Worn bearings or overheating due to poor lubrication
  • Steam pipes near dust deposits.

Human factors

  • Using non-intrinsically safe tools in hazardous zones.
  • Ignoring grounding/bonding procedures.
  • Poor housekeeping leading to dust accumulation

5. Procedures to Prevent or Mitigate Dust Accumulation

To mitigate risks, strict dust control measures should be implemented, such as:

  • Minimizing dust generation: using granulated materials instead of fine powders where possible and reduce”drop heights” when materials are being poured.
  • Optimise airflow on extraction systems to avoid pulling excessive fines into the system
  • Localized extraction: installing capture hoods and ducted exhaust systems at dust generation points
  • Ducting systems should be designed to avoid dead spaces where dust can accumulate
  • Surface cleaning: using approved vacuum systems instead of dry sweeping or compressed air. Dampened cloths may be used for routine cleaning during operations.
  • Humidity control: maintain adequate humidity levels (if possible) using humidifiers or misting systems to reduce airborne dust.
  • Regular housekeeping: implementing scheduled cleaning with wet wiping.
  • The working area where screening, grinding, blending, and other processing of static-sensitive explosive materials is done shall be provided with approved static controls.
  • Reduce the number of transfers in material handling operations
  • Use appropriate dust-tight packaging for products to limit dust escape during storage and transport.
  • Use non-sparking tools during cleaning and maintenance activities.

6. Dust Collection

Explosive dust shall be collected using a “wet” collector system or other approved means. Wetting agents shall be compatible with the explosive materials being collected. Example: some detonating cord extruders (plastic jacket) capture PETN dust in a vacuum system designed with a water trap. Same system can be found in detonators press equipped with vacuum cleaning system (PETN/Lead Azide).

Dust-handling equipment such as driers, cyclones and ducts may constitute an explosion hazard, but tends to be rather weak. It should be separated from other plant by a wall and vented. Vents should be short and should go through the roof.
Some equipment such as cyclones are often placed outside the building and this is preferable to ducting a vent to the outside. Vents should pass to a safe area. Mills are relatively strong and are not usually provided with explosion relief.
Dust should be transferred through chokes??Do you mean the transfer line should be fitted with a flame arrestor? to prevent the transmission of fire or explosion. Surfaces which might collect dust should be kept to a minimum. Dust hazards are considered further in (Frank Lees - Lee’s Loss Prevention in the Process Industries).

7. Design of Dust Collection and Extraction Systems

Engineering design of collection and extraction systems play an important role in preventing hazardous dust dispersion and ignition risks:

Explosion-Proof Design

  • Explosion-Proof Components. Fans, motors, and other electrical components must be certified explosion-proof (e.g., ATEX, NFPA 68/69 compliance)
  • Grounding and Bonding. Ensure all system parts are electrically grounded to prevent static buildup and sparks
  • Ducts should be constructed from conductive materials to prevent static charge buildup.

Point-of-Generation Collection. Install dust extraction systems directly at the source of dust generation (e.g., mixing tanks, grinding mills, or packaging lines).

Sealed Connections: Use sealed or enclosed ducts to prevent dust leakage.

Dedicated Exhaust Lines. Separate systems for different explosives or pyrotechnic types to avoid cross-contamination or reactive interactions.

Proper Airflow Design

  • Sufficient Capture Velocity. Maintain appropriate airflow velocity to transport dust without deposition in the ducts (according with dust properties)
  • Ducts should have smooth interiors and minimal bends to reduce dust settling.

Filtration and Collection:

  • Efficient Filters. Use High-Efficiency Particulate Air (HEPA) filters or equivalent to designed for explosive dust
  • Explosion Protection on Collectors. Install explosion vents, suppression systems, or isolation valves to mitigate explosions in dust collectors

Emergency Shutdown Mechanisms

  • Fire Suppression: integrate fire detection and suppression systems to deal with ignition events
  • Design easy access for maintenance: include access doors for inspection and cleaning of ducts and filters
  • Explosion Isolation: analyze the possibility of installing isolation valves or barriers to prevent explosions from propagating through ducts.
  • Explosion relief devices: incorporate explosion relief panels or rupture discs designed to direct explosions safely away from personnel and equipment.
  • Automatic Shutdowns: consider interlocks to alarm and shut down in case of unsafe or abnormal conditions

8. Maintenance

Effective dust control requires regular maintenance of extraction and ventilation systems:

  • Routine inspections: Checking ductwork, filters, system integrity and extraction points for blockages or wear. In some places it is been used a thin flexible tube with a small camera inside (like endoscope) which is passed through ducts of the exhaust system to inspect the degree of contamination and the effectiveness of cleaning practices.
  • Filter replacement schedules: Ensuring that dust collection filters are changed periodically.
  • Cleaning procedures: Conducting controlled cleaning to prevent excessive dust accumulation inside ducts. Decontamination procedures prior to any dismantling will vary from material to material.
  • Cleaning Frequency: The system shall be cleaned at a frequency that eliminates hazardous concentrations of explosive dusts from accumulating in pipes, tubing, or ducts. It is not possible to immediately establish the ideal frequency, as it depends on each process and the production volume. Observe the accumulation over a week. If there is no accumulation, increase the inspection to every two weeks and gradually increase the time until you find the ideal frequency.
  • Avoid sweeping or compressed air, which can disperse dust into the air and generate static.

9. Personnel Practices

  • Minimized Presence. Limit the number of personnel in areas where dust is generated
  • Proper PPE. Provide workers with appropriate personal protective equipment, such as respirators and anti-static clothing
  • Training. Train personnel on minimizing dust during handling and the importance of adhering to safety protocols

10. Documentation and Audits

  • Maintain detailed records of inspections, incidents, and repairs
  • Periodically review system performance and safety measures

11. References and sources of information

Regulatory and Safety Organizations

1. NFPA (National Fire Protection Association) – USA

  • NFPA 484: Standard for Combustible Metals
  • NFPA 652: Standard on the Fundamentals of Combustible Dust
  • NFPA 654: Standard for the Prevention of Fire and Dust Explosions
  • NFPA 68: Standard on Explosion Protection
  • Website: www.nfpa.org

2. ATEX (EU Directive on Explosive Atmospheres) – Europe

3. OSHA (Occupational Safety and Health Administration) – USA

  • OSHA 1910.1000: Air Contaminants
  • OSHA Combustible Dust National Emphasis Program (NEP)
  • Website: www.osha.gov

4. HSE (Health and Safety Executive) – UK

  • HSG103: Safe handling of combustible dusts
  • DSEAR (Dangerous Substances and Explosive Atmospheres Regulations)
  • Website: www.hse.gov.uk

5. CSB (Chemical Safety Board) – USA

  • Investigation reports on dust explosions
  • Website: www.csb.gov

Technical Guidelines and Industry Associations

6. SAFEX (International Association of Explosives Manufacturers)

7. IChemE (Institution of Chemical Engineers) – UK

  • Process safety guidelines for explosive materials
  • Website: www.icheme.org

8. ECHA (European Chemicals Agency) – EU

9. VDI (Association of German Engineers) – Germany

  • VDI 2263: Dust explosion protection in industrial plants
  • Website: www.vdi.de