1. Combustible Dust: Recognizing the Hazard
SACHE Workshop 2005
Combustible Dust:
Recognizing the Hazard

2. Topics Introducing the CSB Dust Explosion Case Histories
Size and Scope of the Problem
Causal Factors
Keys to Prevention
CSB Dust Study

3. Introducing the CSB Authorized by 1990 Clean Air Act Amendments
Governed by a Board appointed by the President for 5 year terms
Independent federal agency
Authorized to investigate accidents and recommend accident prevention
Does not promulgate regulations or issue fines or penalties

4. CSHIB Mission
To promote prevention of industrial chemical accidents that harm employees, damage the environment and endanger the public through scientific investigations that determine root and contributing cause, and implementation of recommendations to reduce the risk and consequences of accidental chemical releases.

5. CSB Common Findings Failure to recognize potential hazards
Failure to address near miss warning events
Failure to maintain safety systems
Lack of technical expertise
Lack of proper engineering and design
Lack of maintenance of production systems
Lack of procedures or training for abnormal operations
Failure to plan for emergency response
Failure to prepare community for emergency

6. CSB Combustible Dust Study
June 22, 2005
CSB Case Histories
West Pharmaceutical Services (completed)
CTA Acoustics (completed)
Hayes Lemmerz International (pending)
The CSB investigated three fatal dust explosions, all of which happened in The following is a brief summary of those investigations.

7. West Pharmaceutical Services
CSB Combustible Dust Study
June 22, 2005
West Pharmaceutical Services
Kinston, NC
January 29, 2003
Polyethylene Powder
The West facility compounded various types and colors of rubber, that was molded into products such as syringe plungers and fittings for IV drug delivery systems.

8. Video courtesy of Lenoir County, NC Department of Emergency Services
CSB Combustible Dust Study
June 22, 2005
Video courtesy of Lenoir County, NC Department of Emergency Services
The video footage I am about to show you was taken by emergency responders for Lenoir County, North Carolina, on the day of the explosion at West. The CSB gratefully acknowledges the Lenoir County Department of Emergency Services and Fire Marshal Deral Raynor for providing this video for our use today. I’ll let it play without narration; the images speak for themselves.

9. West Pharmaceutical Services
CSB Combustible Dust Study
June 22, 2005
West Pharmaceutical Services
This is an aerial photograph of the West facility, taken a few hours after the explosion. The tower structure <here> housed the rubber compounding process. The steel cladding and roof were blown off by the explosion. Employees in the plant described the sound of rolling thunder as secondary dust explosions quickly propagated through the building. The fire you see burning is in the raw materials warehouse, where West stored bales and pallets of rubber. Debris from the explosion was blown and carried by the wind as far as two miles from the facility, setting off numerous woods fires.

10. West Pharmaceutical Services
CSB Combustible Dust Study
June 22, 2005
West Pharmaceutical Services
6 dead, 38 injured
Facility virtually destroyed
Rubber compounding process
Fuel for dust explosion was polyethylene powder
Used as a slab dip for sheets of rubber
Dried residue accumulated above suspended ceiling
The polyethylene that fueled the explosion was used in the plant as an anti-tack agent to keep sheets of rubber from sticking together as the long strips of fresh rubber were folded for shipment or molding. Fine polyethylene powder in a slurry of water and surfactant was called “slab dip”; the freshly formed rubber sheets ran through a tank containing this slurry. This also helped to cool the rubber. As the slab dip dried on the rubber, some residue was carried by air currents to the space above the ceiling tiles, where it settled out. The dust layer varied from very thin deposits to inches deep on some beams.

11. CSB Combustible Dust Study
June 22, 2005
This photograph shows the structure of the rubber compounding building. You can clearly see where wall beams were bent by the explosion.

12. West Pharmaceutical- Selected Findings
CSB Combustible Dust Study
June 22, 2005
West Pharmaceutical- Selected Findings
MSDS dip did not convey dust hazard
Workers unaware of hazard
Material review did not address dust explosion hazard
Inspectors failed to identify hazard
Area above ceiling not cleaned
Pertinent fire codes not applied
The MSDS for slab dip did not address hazards of combustible dust if the polyethylene was dried to powder form, and the workers at West—the ones who knew that dust had accumulated above the ceiling tiles—were not informed of the dust explosion hazard.
When West changed anti-tack agent from zinc stearate to polyethylene, the review did not include combustible dust issues
Prior inspections by NC OSHA, insurance providers and others failed to identify a combustible dust hazard
Although extensive effort went into keeping the visible production areas clean, the area above the suspended ceiling was not cleaned
North Carolina fire code incorporated NFPA dust standards by reference, but the design and operation of facility did not meet those requirements.

13. CSB Combustible Dust Study
June 22, 2005
CTA Acoustics
Corbin, KY
February 20, 2003
Phenolic Resin
CTA Acoustics manufactured automotive insulation forms from fiberglass mats that were impregnated with phenolic resin. The formed parts were cured in gas-fired ovens.

14. CSB Combustible Dust Study
June 22, 2005
CTA Acoustics
This photograph shows the general extent of damage to the CTA Acoustics production facility, as secondary dust explosions propagated throughout the building.

15. CSB Combustible Dust Study
June 22, 2005
CTA Acoustics
7 dead, 37 injured
Widespread facility damage
Fuel was phenolic resin
Lofted by cleaning
Ignited by flames from open door of curing oven
Secondary explosions traversed facility
The largest CTA customer, Ford Motor Company, temporarily suspended operations at four automobile assembly plants, resulting in numerous layoffs.
The phenolic resin used at CTA was a fine, talc-like powder. This material is easily lofted, has a low ignition energy and is more explosive than other plastics, such as polyethylene.

16. CSB Combustible Dust Study
June 22, 2005
This is a close-up photograph of the open curing oven that may have ignited the first of a series of resin dust explosions.

17. CTA Acoustics - Selected Findings
CSB Combustible Dust Study
June 22, 2005
CTA Acoustics - Selected Findings
Measures not implemented to prevent dust explosions
Hazard not communicated to workforce
Inefficient baghouse operation
Lack of housekeeping
Prior inspectors failed to identify hazard
Pertinent fire codes not applied
CTA management was aware of the explosive potential of dusts, but did not implement effective measures to prevent explosions or communicate the explosion hazard to the general workforce
Inefficient baghouse operation deficient housekeeping resulted in unsafe dust accumulations on many surfaces
Kentucky OSHA and risk insurance providers had inspected the facility prior to the explosion but did not identified the combustible dust hazard
CTA management had not applied principles of pertinent and applicable fire standards to prevent dust explosions.
Lack of effective firewalls and blast-resistant physical barriers contributed to damage propagation through the facility

18. Hayes Lemmerz International
CSB Combustible Dust Study
June 22, 2005
Hayes Lemmerz International
Huntington, IN
October 29, 2003
Aluminum Dust
Hayes Lemmerz manufactured cast aluminum and aluminum alloy wheels at the Huntington, Indiana facility. The wheels produced at this plant went on new cars for nearly every major automotive manufacturer in the United States. Newly cast wheels were polished and machined, producing scrap that was returned to the foundry area for remelting.

19. Hayes Lemmerz International
CSB Combustible Dust Study
June 22, 2005
Hayes Lemmerz International
This photograph was taken by a photo journalist while the fire was still in progress. The bright light at the left is the dust collector, which was still involved in a fire at the time. This photo also shows the damage to the roof and walls in this section of the building.

20. Hayes Lemmerz 1 dead, 6 injured
Scrap remelting equipment & dust collector damaged
Final investigation report pending

21. Other Notable Dust Explosions
CSB Combustible Dust Study
June 22, 2005
Other Notable Dust Explosions
Malden Mills (1995)
Ford River Rouge Power Plant (1999)
Jahn Foundry (1999)
Rouse Polymerics (2002)
Several other significant dust explosions that occurred in industry in the past several years are worth mentioning here. These are…

22. Malden Mills Industries
CSB Combustible Dust Study
June 22, 2005
Malden Mills Industries
Methuen, MA
December 11, 1995
37 injured
Nylon fiber explosion
The explosion at the Malden Mills factory occurred on December 11, people were injured in an explosion of nylon fibers. The owner of the company kept the employees on the payroll long after the explosion, however efforts to sustain the business were not successful and the business was eventually sold.

23. Ford River Rouge Power Plant
CSB Combustible Dust Study
June 22, 2005
Ford River Rouge Power Plant
Dearborn, MI
February 1, 1999
6 dead, 30 injured
Secondary coal dust explosion
On February 1, 1999 a natural gas explosion at the power plant for the Ford River Rouge facility triggered subsequent secondary explosions of coal dust that had accumulated on surfaces in the plant. Six people died and another 30 were injured. The power plant had to be completely rebuilt.

24. CSB Combustible Dust Study
June 22, 2005
Jahn Foundry
Springfield, MA
February 25, 1999
3 dead, 9 injured
Phenolic resin explosion
Nearly three years to the day before the CTA Acoustics explosion, a phenolic resin explosion at the Jahn Foundry in Springfield, Massachusetts resulted in the deaths of three people and injured 9 others. The resin that fueled this explosion was quite similar to and made by the same company as the resin that exploded at CTA. This manufacturer did not warn their customers of the explosion hazard after to the Jahn Foundry explosion.

25. Rouse Polymerics, International
CSB Combustible Dust Study
June 22, 2005
Rouse Polymerics, International
Vicksburg, MS
May 16, 2002
5 dead, 7 injured
Rubber dust explosion
On May 16, 2002, Rouse Polymerics was rocked by an explosion of rubber dust that injured 12 people. Although no one was killed in the initial explosion, five of the victims eventually perished from their injuries.

26. A few isolated cases, or a big problem?
CSB Combustible Dust Study
June 22, 2005
A few isolated cases, or a big problem?
197 Incidents since 1980
109 Fatalities
592 Injuries
Due to the limitations of the data sources, the results of the analysis are acknowledged as only a sampling of recent dust incidents, and this precludes the CSB from drawing statistical conclusions on trends in the number or severity of dust incidents.
Limited data available to CSB includes 197 serious industrial incidents in the US involving dust since 1980.

27. …and this did NOT include
CSB Combustible Dust Study
June 22, 2005
…and this did NOT include
Grain handling facilities
Coal mining incidents
Incidents in non-manufacturing sectors (universities, hospitals, military, retail)
Transportation related incidents
Incidents occurring outside the U.S.
Mention limits of data, results only a sampling…….. Due to the limitations of the data sources, the results of the analysis are acknowledged as only a sampling of dust incidents, and this precludes the CSB from drawing statistical conclusions on trends in the number or severity of dust incidents.

28. Dust Incidents/Year
1998
2003

29. Thin Dust Layers Can Be Hazardous
CSB Combustible Dust Study
June 22, 2005
Thin Dust Layers Can Be Hazardous
NFPA 654 states that dust layers 1/32 inch thick can create hazardous conditions.
1/32 in.is less than the thickness of a dime.
Fine particles of coal, aluminum, plastic, vitamins, pharmaceutical compounds and corn starch are all examples of dusts than can be explosive under certain conditions.

30. Materials involved in incidents

31. Incidents occur in many industries

32. Incidents occur nationwide
Illinois 21
California 19
Ohio 13
Indiana 12
Pennsylvania 11
Iowa 10
North Carolina 8
Maryland 8
Virginia 7
Oregon 6
New Hampshire 6
Minnesota 6
Kentucky 3

33. Causal Factors for Dust Explosions
Lack of hazard awareness
Inadequate hazard evaluation
Failure to comply with NFPA standards
Poor housekeeping
Inadequate change management
Failure to investigate and respond to previous incidents

34. Awareness of the Hazard
MSDSs do not convey the explosion hazard
Employees not trained about dust explosion prevention
Third-party inspections with no recognition of the hazard

35. Hazard Evaluation Often, no hazard analysis performed
Focus on exposure hazards but not facility process safety issues

36. NFPA Standards
NFPA-654, NFPA-484 and others have been around in one form or another for decades
Adopted as fire code in many states
Little or no inspection or enforcement

37. Housekeeping
The worst damage from a dust explosion is often the result of one or more secondary explosions.

38. Secondary Dust Explosion Mechanism
CSB Combustible Dust Study
June 22, 2005
Secondary Dust Explosion Mechanism
Dust settles on flat surfaces
Some event disturbs the settled dust into a cloud
It is not uncommon for more than one dust explosion to occur at a facility where combustible dust is present.
When combustible dust is involved, the worst damage and injuries can often occur some distance away from the initiating event. The pressure wave from the first explosion shakes loose dust from flat building surfaces forming a cloud which is then ignited by the flame front following it. This phenomenon is often called a secondary explosion.
Dust cloud is ignited and explodes

39. Thin Dust Layers Can Be Hazardous
CSB Combustible Dust Study
June 22, 2005
Thin Dust Layers Can Be Hazardous
NFPA 654 states that dust layers 1/32 inch thick can create hazardous conditions.
1/32 in.is less than the thickness of a dime.
Fine particles of coal, aluminum, plastic, vitamins, pharmaceutical compounds and corn starch are all examples of dusts than can be explosive under certain conditions.

40. Change Management
Major modifications performed without adequate design review, hazard analysis or documentation

41. Incident Investigation
Precursor events
Small deflagrations or fires
Events at other facilities
“Whew” events (if not for the safety device, this could have been bad)
Not reported
Not investigated
No corrective actions taken
Findings not communicated to employees

42. Keys to Prevention Increased hazard awareness
Improved MSDSs
Dust explosions taught in undergrad curriculae
Access to NFPA standards
Applied principles of PSM
Change management
Hazard evaluation
Incident investigation
Hazard communication

43. CSB’s Dust Explosion Study
CSB Combustible Dust Study
June 22, 2005
CSB’s Dust Explosion Study
Dust explosions are serious safety concern
Effects are significant
No federal regulation
Common issues
Dust explosions cause significant damage, serious and often fatal burn injuries, and result in job losses and community economic impact.
Investigations of West, CTA and Hayes Lemmerz accidents highlighted that there is no federal regulation that addresses dust explosion prevention in general industry
Common issues from CSB investigations:
Inadequacy of MSDSs
Inconsistency of fire code adoption and enforcement
Lack of awareness of the hazard by management, engineers, safety professionals and workers.

44. Conclusion
Most important key to prevention is increasing awareness of the hazard

45. For more information…

46. To contact me: