Combustible Dust National Emphasis Program

1. Ignition Source Combustible Dust National Emphasis Program Ignition Source Dispersion Confinement Deflagration Explosion FIRE Oxygen in Air/Oxidizers Combustible Dust March 25, 2010

2. Overview • History of Combustible Dust Incidents • Hazard Mitigation Techniques • Combustible Dust NEP

3. Catastrophic Combustible Dust Incidents since 1995

4. Combustible Dust Explosions History Malden Mills Methuen, MA December 11, 1995 37 Injured Nylon Fiber

5. Firefighting efforts following the explosion at Malden Mills (Methuen, Massachusetts, December 11, 1995).

6. Combustible Dust Explosions History Jahn Foundry Springfield, MA February 26, 1999 3 dead9 Injured Phenolic resin dust

7. Combustible Dust Explosions History May 16, 2002 Rouse Polymerics Vicksburg, MS 5 dead, 7 injured Rubber Dust

8. Combustible Dust Explosions History • January 29, 2003 - West Pharmaceutical Services, Kinston, NC • Six deaths, dozens of injuries • Facility produced rubber stoppers and other products for medical use • Plastic powder accumulated above suspended ceiling ignited

9. West Pharmaceutical facility destroyed by polyethylene dust

10. Combustible Dust Explosions History • February 20, 2003 – CTA Acoustics Corbin, KY • Seven Workers died • Facility produced fiberglass insulation for automotive industry • Resin accumulated in production area and was ignited

11. http://www.csb.gov/completed_investigations/docs/CSBFinalReportCTA.pdfhttp://www.csb.gov/completed_investigations/docs/CSBFinalReportCTA.pdf

12. Imperial SugarPort Wentworth, Georgia 14Killed Many Hospitalized February 7, 2008 Sugar Involved

13. Types of Dust Involved in incidents

14. Types of Industries Involved in Dust Incidents

15. Definitions and Terminology • Combustible Dust • Combustible Particulate Solid • Hybrid Mixture • Class II Locations • Deflagration • Detonation • Explosion • Minimum Explosible Concentration (MEC) • Lower Flammable Limit (LFL) • Upper Flammable Limit (UFL) • Minimum Ignition Temperature (MIT) • Minimum Ignition Energy (MIE)

16. Definitions and Terminology NFPA 654 (2006) Definitions Combustible dust. A combustible particulate solid that presents a fire or deflagration hazard when suspended in air or some other oxidizing medium over a range of concentrations, regardless of particle size or shape.Combustible Particulate Solid. Any combustible solid material composed of distinct particles or pieces, regardless of size, shape, or chemical composition.Hybrid Mixture. A mixture of a flammable gas with either a combustible dust or a combustible mist. What is Combustible Dust?

17. Definitions and Terminology What is Combustible Dust? NFPA 69 (2002), and 499 (2004) Definitions • Combustible Dust.Any finely divided solid material 420 microns or less in diameter (i.e., material passing through a U.S. No 40 Standard Sieve) that presents a fire or explosion hazard when dispersed 1 micron (µ) = 1.0 x 10-6m  = 1.0 x 10-4 cm = 1.0 x 10-3 mm  420 µ = 420 x 10-4 cm = .042 cm = 0.4mm A typical paper thickness is approximately 0.1mm

18. Standard Sieve Sizes

19. Particle Size of Common Materials

20. Increase of Surface Area Surface Area Increases with increasing subdivision Figures Source: Dust Explosions in the Process Industries, Second Edition, Rolf K Eckhoff

21. Combustion Rate Increase Combustion Rate Increases with Increasing Subdivision Fast Combustion Deflagration/Explosion Slow Combustion Source: Dust Explosions in the Process Industries, Second Edition, Rolf K Eckhoff

22. Deflagration Vs. Explosion Definitions and Terminology Deflagration. Propagation of a combustion zone at a speed that is less than the speed of sound in the unreacted medium. Detonation. Propagation of a combustion zone at a velocity that is greater than the speed of sound in the unreacted medium. Explosion.The bursting or rupture of an enclosure or a container due to the development of internal pressure from deflagration. Deflagration Explosion Detonation

23. Explosible Range Dust Deposit IH Range Explosible Range 10-3 10-2 10-1 1 10 101 102 103 104 105 106 MASS OF POWDER/DUST PER UNIT VOLUME [g/m3] Source: Dust Explosions in the Process Industries, Second Edition, Rolf K Eckhoff

24. Dust Fire/Explosion Ignition Source Confinement Dispersion Deflagration Explosion FIRE Oxygen in Air Combustible Dust

25. Initial Internal Deflagration Process Equipment 0 25 50 75 100 125 150 175 200 225 250 300 325 Time, msec. The “Typical” Explosion Event

26. Initial Internal Deflagration Shock Wave Process Equipment 0 25 50 75 100 125 150 175 200 225 250 300 325 The “Typical” Explosion Event Time, msec.

27. Initial Internal Deflagration Elastic Rebound Shock Waves Process Equipment 0 25 50 75 100 125 150 175 200 225 250 300 325 Time, msec. The “Typical” Explosion Event

28. Initial Internal Deflagration Dust clouds caused by Elastic Rebound Process Equipment 0 25 50 75 100 125 150 175 200 225 250 300 325 Time, msec. The “Typical” Explosion Event

29. Containment Failure from Initial Deflagration Dust Clouds Caused by Elastic Rebound Process Equipment 0 25 50 75 100 125 150 175 200 225 250 300 325 Time, msec. The “Typical” Explosion Event

30. Dust Clouds Caused by Elastic Rebound Process Equipment Secondary Deflagration Initiated 0 25 50 75 100 125 150 175 200 225 250 300 325 Time, msec. The “Typical” Explosion Event

31. Secondary Deflagration Propagates through Interior Process Equipment 0 25 50 75 100 125 150 175 200 225 250 300 325 Time, msec. The “Typical” Explosion Event

32. Secondary Deflagration Vents from Structure 0 25 50 75 100 125 150 175 200 225 250 300 325 Time, msec. The “Typical” Explosion Event Process Equipment

33. Secondary Deflagration Causes Collapse and Residual Fires 0 25 50 75 100 125 150 175 200 225 250 300 325 Time, msec. The “Typical” Explosion Event Diagrams Courtesy of John M. Cholin, P.E., FSFPE, J.M. Cholin Consultants, Inc.

34. Hazard Mitigation

35. Hazard Mitigation • Dust control • Ignition source control • Explosion Prevention

36. Dust Control • Design of facility & process equipment • Contain combustible dust • Clean fugitive dust • Regular program • Access to hidden and overhead areas • Safe cleaning methods

37. Ignition Source Control • Electrical equipment • Static electricity control • Mechanical sparks & friction • Open flame control • Design of heating systems & heated surfaces • Use of tools, & vehicles

38. Explosion Prevention • Oxidant Concentration Reduction • Deflagration Venting • Deflagration Pressure Containment • Deflagration Suppression Systems • Isolation of equipment

39. OSHA Standards/Citations Includes: • Ventilation Standard • Housekeeping Standard. • Housekeeping in storage areas. • Section 5(a)(1) (general duty clause) • Housekeeping violations at coal-handling operations • Personal Protective Equipment (PPE) • Process Safety Management • Electrical • Powered Industrial Trucks • Welding, cutting, and brazing • Warning Signs • Hazard communication • Egress • Fire protection

40. Partial List of Relevant NFPA Standards

41. Inspections Conducted

42. Types of Industries Inspected by Percent

43. Industries Inspected under NEP

44. Total Violations Issued

45. % Inspections In-Compliance(Insps W/O Violations & Closed)

46. 700 600 500 439 388 400 300 234 232 193 171 200 151 88 100 55 0 PPE 5(a)(1) HazCom First Aid House Keeping Compressed Air Fire Extinguishers Electrical (Haz Loc) Powered Industrial Trucks* Combustible Dust Related Violations *The number of violations pertaining to powered industrial trucks includes those that are combustible dust related (approved for class II locations) and other violations (e.g., training and other items covered under 1910.178).

47. Combustible Dust Related Violations

48. Some Combustible Dust NEP Findings • Hazardous levels of dust accumulations in the workplaces due to poor housekeeping practices. • Electrical equipment and Powered Industrial Trucks not approved for locations handling combustible dusts • Dust collectors were located inside buildings without proper explosion protection systems, such as explosion venting or explosion suppression systems. • Deflagration isolation systems were not provided to prevent deflagration propagation from dust handling equipment to other parts of the plant. • The rooms with excessive dust accumulations were not equipped with explosion relief venting distributed over the exterior walls and roofs of the buildings.

49. Some Combustible Dust NEP Findings • The horizontal surfaces such as beams, ledges and screw conveyors at elevated surfaces were not minimized to prevent accumulation of dust on surfaces. • Air from the dust collector was recycled through ductwork back into the work area. • Magnetic separators and tramp metal separators were not installed or not functioning to prevent foreign material process stream and potentially cause a spark • Explosion vents on bucket elevatior(s) and dust collectors were directed into work areas and not vented to a safe, outside location away from platforms, means of egress, or other potentially occupied areas

50. Some Combustible Dust NEP Findings 10. Equipment (such as grinders and shakers) were not maintained to minimize escape of dust into the surrounding work area. 11.Ductworks used in transporting combustible dust were not constructed of metal (conductive) and were not bonded or grounded to minimize generation and accumulation of static electricity. 12. Hot work (open flame or sparks from welding, cutting, grinding) was performed in the combustible dust handling areas without hot work procedures.