Always know the hazardous properties

1. Any material that will burn can pose significant dust combustibility hazards. Combustible dusts can be involved in  layer fires, flash fires involving suspended dust clouds, and explosions that can damage facilities and equipment and harm personnel.  Initial explosions can suspend additional dust clouds that can lead to  large secondary explosions. (link to graphic that demonstrates this)
2. Personnel in facilities need to know the hazardous properties of process materials  so they can understand their role in guarding against the hazards.  
3. Knowledge of the hazardous properties is a necessary input for the assessment of hazards and the design of protections.

Incident history -

• On January 29, 2003, an explosion and fire destroyed the West Pharmaceutical Services plant in Kinston, North Carolina, causing six deaths, dozens of injuries, and hundreds of job losses. The facility produced rubber stoppers and other products for medical use. The fuel for the explosion was a fine plastic powder, which accumulated above a suspended ceiling over a manufacturing area at the plant and ignited. Although the plant had the SDS warning about the explosive properties of polyethylene powder, employees had not received any significant training about combustible dust hazards. If maintenance workers been aware of the catastrophic nature of this hazard, they could have alerted management to the presence of dangerously large accumulations above the acoustic ceiling. (Ref 15)
• On the evening of October 29, 2003, a series of explosions severely burned two workers, injured a third, and caused property damage to the Hayes Lemmerz manufacturing plant in Huntington, Indiana. One of the severely burned men subsequently died. The Hayes Lemmerz plant manufactures cast aluminum automotive wheels, and the explosions were fueled by accumulated aluminum dust, a flammable byproduct of the wheel production process. Hayes did not perform reviews to address the hazards of Aluminum dust. The hazards of aluminum dust were neither identified nor addressed. (Ref 14)

• Screen to determine if the dust is combustible based on testing or historical data (Ref. 1, 2, 3, 13)
• If combustible, do detailed testing to quantify explosibility properties. Suggested testing is situation- specific and could include (Ref. 1, 2, 3, 13):

1. Deflagration index of a dust cloud (Kst)
2. Maximum pressure developed in a contained deflagration of an optimum mixture (Pmax)
3. Minimum Ignition energy (MIE)
4. Minimum Explosible Concentration (MEC)
5. Limiting Oxidant Concentration (LOC)
6. Conductivity
7. Ignition temperature (layer and Cloud)
8. Others as appropriate

• Evaluate chemical incompatibilities such as water reactivity, interaction with other process chemical including inerting materials. (Ref. 4,5,6)
• Consider other hazards such as thermal instability and  toxicity. (Ref. 7, 13)
• Document hazardous properties in your Process Knowledge Management data base.

• Seek out and participate in training on hazardous properties of material being used
• Understand the nature of the hazards (fires, explosions and potential toxic events)(Ref.1)
• Know and fulfill your responsibilities for controlling the hazards (Ref. 1, 2)
• Understand the PPE requirements for the materials that are handled (Ref. 7, 8)

• Support obtaining the required test data  (Ref, 1, 2, 3)
• Support training for operators on hazardous properties of materials being used.
• Define and enforce expectations for operating disciplines around hazards
• Monitor operations for new or changed hazards

Never use generic or literature data for hazard assessments or design (Ref, 1, 2, 3)

• Know the hazardous properties of process materials and combustion products (Ref. 8, 9, 10)
• Be aware of the unique aspects of fighting combustible dust fires (Ref. 8, 9, 10)
• Be aware of required PPE for fighting combustible dust fires (Ref 7)

1. NFPA Guide to Combustible Dusts
2. NFPA 652- Standard on the Fundamentals of Combustible Dust
3. Dust Explosions in the Process Industries-Eckhoff
4. Bretherick’s Handbook of Reactive Chemical Hazards
5. Wiley Guide to Chemical Incompatibilities
6. AICHE Chemical reactivity worksheet   
7. Safety Data Sheets
8. Manufacturer’s or Trade Association’s Safe Handling Guides (for example- Guidelines for Handling Aluminum Fines-Aluminum Association)
9. OSHA Firefighting Precautions at Facilities with Combustible Dusts (OSHA Publication 3644-04)
10. The OSHA pamphlet on fighting fires in silos
11. “Incidents That Define Process Safety”-Atherton/Gill-A CCPS concept book-2008
12. COMBUSTIBLE DUST HAZARD STUDY - REPORT NO. 2006-H-1, NOVEMBER 2006, U.S. CHEMICAL SAFETY AND HAZARD INVESTIGATION BOARD (CSB)-
13. CCPS-Guidelines for Safe Handling of Powders and Bulk Solids
14. CSB - Hayes Lemmerz Dust Explosions and Fire-Final Report-9/27/2005
15. CSB - West Pharmaceutical Services Lemmerz Dust Explosions and Fire-Final Report-9/23/2004