Office of Safety & Health Consultation presents Combustible Dust Notes: Safety & Health Consultation

Goal To improve the safety of workers in environments where combustible dusts may be encountered by increasing employee awareness of this hazard and by demonstrating how the hazard can be recognized and addressed in their workplace. Safety & Health Consultation

Objectives Identify the elements necessary for dust to explode. Explain how to prevent dust from reaching combustible levels. Describe the difference between primary and secondary dust explosions. Safety & Health Consultation

Introduction A Chemical Safety Board Study Shows: From 1996 to 2005, a total of 106 explosions resulted in 16 fatalities and 126 injuries, at an estimated cost of $162.8 million in damages to the facilities. In 2005, there were 13 grain dust explosions reported in the US. Safety & Health Consultation

Organic Dust Fires & Explosions Organic Dust Fires and Explosions: Massachusetts (3 killed, 9 injured) North Carolina (6 killed, 38 injured) Safety & Health Consultation

Massachusetts Incident Fire in a foundry shell molding machine Caused a primary explosion in ducts containing heavy deposits of Phenol formaldehyde resin dust. Resulted in a dust cloud from ledge dust deposits outside the ducts and an explosion in the plant area. Safety & Health Consultation

North Carolina Incident Combustible polyethylene dust accumulated above suspended ceilings at pharmaceutical plant A fire at the plant caused dust to be dispersed and explode in the ceiling space Safety & Health Consultation

Grain Handling Industry Experience In the late 1970s, grain dust explosions left 59 people dead and 49 injured. Safety & Health Consultation

Grain Handling Industry Experience In 1987, OSHA promulgated the Grain Handling Facilities standard (29 CFR 1910.272) still in effect Safety & Health Consultation

Combustible Dust Explosions Imperial Sugar 2008 Malden Mills 2004 Dust Kansas 2011 Safety & Health Consultation

What’s so bad about a little dust? Safety & Health Consultation

It’s Only Dust Safety & Health Consultation

It’s Only Sugar! Safety & Health Consultation

A Chronology of Past Events February 7, 2008 – Imperial Sugar Plant explodes February 11, 2008 – Fire still burning in parts of plant February 24,2008 – 11th worker dies from injuries July 2008 – OSHA fines Imperial Sugar Co. $8.8 million For violations in Georgia and Louisiana August 2008 – 14th worker dies from injuries Safety & Health Consultation

What’s so bad. For the employer the millions of dollars in OSHA fines and insurance payments not to mention the cost of rebuilding the plant . For the workers and their families – the cost, heartbreak and pain – That 14th worker spent 6 months in a burn unit fighting for his life. A total of 40 other workers were injured with severe burns. Safety & Health Consultation

That averages to more than 10 explosions per year Between 1980 and 2005 the Chemical Safety Board has knowledge of over 280 dust explosions resulting in 119 deaths and 718 injuries That averages to more than 10 explosions per year Despite the time since the Port Wentworth explosion brought this issue to the national forefront the explosions continue. 10/30/2011 6 killed, 2 injured Kansas Safety & Health Consultation

Important Points Regarding the CSB Data According to the CSB, “The combustible dust incidents the CSB lists…from 1980 to 2005 are likely only a small sampling, as no federal or state agency keeps specific statistics on combustible dust incidents, nor does any single data source provide a comprehensive collection of these incidents. Information about small combustible dust incidents and near-misses is also generally unavailable. Incidents that cause no fatalities, significant injuries or major fires may not be recorded in the OSHA and fire incident databases The true extent of the problem is likely understated. Due to these limitations, the CSB does not represent the incident data as complete or error free and other compilations of dust explosion data are available.” Safety & Health Consultation

Dust Incidents, Injuries & Fatalities 1980 - 2005 (Not even close to being a complete summary of incidents) Fatalities Injuries Incidents Injuries / Fatalities Incidents Figure 11. Dust incidents, injuries & fatalities, 1980-2005 Source: Chemical Safety Board Safety & Health Consultation

Types of Industries Involved in Dust Incidents Safety & Health Consultation

Types of Dust Involved in incidents Safety & Health Consultation

Combustible Dust Explosions History Malden Mills Methuen, MA December 11, 1995 37 Injured Nylon Fiber Safety & Health Consultation

Combustible Dust Explosions History Jahn Foundry Springfield, MA February 26, 1999 3 dead 9 Injured Phenolic resin dust Safety & Health Consultation

Combustible Dust Explosions History Ford River Rouge: Secondary Coal Dust Explosion February 1, 1999 Killed six workers and injured 36 Safety & Health Consultation

Combustible Dust Explosions History May 16, 2002 Rouse Polymerics Vicksburg, MS 5 dead, 7 injured Rubber Dust Safety & Health Consultation

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 Safety & Health Consultation

West Pharmaceutical facility destroyed by polyethylene dust Safety & Health Consultation

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 Safety & Health Consultation

Combustible Dust Explosions History October 29, 2003 Hayes Lemmerz Manufacturing Plant Two severely burned (one of the victims died) Accumulated aluminum dust Facility manufactured cast aluminum automotive wheels Safety & Health Consultation

Combustible Dust Explosions History October 30, 2011 Bartlett Grain Elevator Atchison Kansas - 6 Workers killed - 2 Workers injured Workers were loading corn onto a train Safety & Health Consultation

The Dust Explosion Pentagon Ignition Source Ignition Source Dispersion Confinement Deflagration Explosion FIRE Combustible Dust Oxygen in Air/Oxidizers To prevent an explosion – remove one corner of the pentagon Safety & Health Consultation

The primary explosion is rarely the end of the story. Safety & Health Consultation

Secondary Explosions Occur when the blast wave from the initial explosion causes accumulated dust in other areas (which may be remote and unrelated to original explosion) to become airborne and explode Anecdotally many investigators discover that “puffs” (small unreported explosions) had been observed for some time prior to the reported incident. Safety & Health Consultation

So How Do I Prevent a Dust Explosion? If one of the five elements of the Pentagon is missing a catastrophic explosion cannot occur. = No Explosion Safety & Health Consultation

Oxygen in Air/Oxidizers FIRE I Ignition Source Ignition Source Dispersion Confinement Deflagration Explosion FIRE Combustible Dust Oxygen in Air/Oxidizers FIRE I FIRE Two elements are difficult to eliminate: Oxygen in Air Confinement within processes or buildings Safety & Health Consultation

Oxygen in Air/Oxidizers Ignition Source Ignition Source Dispersion Confinement Deflagration Explosion FIRE Combustible Dust Oxygen in Air/Oxidizers FIRE I But my process doesn’t include dust! Are you sure? If you work with any solid combustible material, ingredients or intermediate products or by-products, handling, conveying, or otherwise manipulating these materials can create combustible dust. Even materials typically handled and stored wet can become dry. FIRE Safety & Health Consultation

Definitions and Terminology What is Combustible Dust? 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. Safety & Health Consultation

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 10-6 m  = 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 Safety & Health Consultation

Good housekeeping might seem like an easy answer. Different dusts of the same chemical material may have different ignitability and explosibility characteristics depending on variables of particle size, shape, and moisture content. Good housekeeping might seem like an easy answer. Safety & Health Consultation

But housekeeping is only part of the answer! As much as is practical, containment and dust collection systems are important. But they must be installed and maintained in a manner that keeps them from becoming an ignition source Safety & Health Consultation

NFPA 654, Standard for the Prevention of Fire and Dust Explosions from the Manufacturing, Processing of Combustible Particulate Solids Recommends: Minimize the escape of dust from process equipment or ventilation systems: Use dust collection systems and filters; Utilize surfaces that minimize dust accumulation and facilitate cleaning; Provide access to all hidden areas to permit inspection; Inspect for dust residues in open and hidden areas (at regular intervals); Clean dust residues (at regular intervals); Only use vacuum cleaners approved for dust collection; Locate relief valves away from dust hazard areas; and 9. Develop and implement a hazardous dust inspection, testing, housekeeping, and control program. Safety & Health Consultation

Use dust collection systems and filters Dust Control Design of facility & process equipment Contain combustible dust Clean fugitive dust Regular program Access to hidden areas Safe cleaning methods Maintenance Safety & Health Consultation

Inspect for dust residues in open and hidden areas (at regular intervals); Like most pharmaceutical manufacturers this was a “clean” facility. West Pharmaceutical facility destroyed by polyethylene dust Which accumulated above the tiles in a dropped ceiling Safety & Health Consultation

NFPA 654, Standard for the Prevention of Fire and Dust Explosions form the Manufacturing, Processing of Combustible Particulate Solids Contains comprehensive guidance on the control of ignition sources: Use appropriate electrical equipment and wiring methods; Control static electricity, including bonding of equipment to ground; Control smoking, open flames, and sparks; Control mechanical sparks and friction; Use separator devices to remove foreign materials capable of igniting combustibles from process; Separate heated surfaces from dusts; Separate heating systems from dusts; Proper use and type of industrial trucks; Proper use of cartridge activated tools; and Adequately maintain all the above equipment. Safety & Health Consultation

Ignition Source Control Electrical equipment Static electricity control Mechanical sparks & friction Open flame control Design of heating systems & heated surfaces Use of tools, & vehicles Maintenance Safety & Health Consultation

Ignition Source Control Electrical equipment Class II, Division 1 and 2 Class I and Class III may also be an issue Consider equipment both inside dust handling equipment and outside Safety & Health Consultation

Ignition Source Control Mechanical sparks & friction Rotating equipment bearing failure can lead to very hot surfaces (above the MIT) Sliding surfaces can develop charges Steel tools dropping onto concrete or steel A good mechanical integrity management system/vibration analysis system is needed to detect problems in advance with bearings and other surfaces Safety & Health Consultation

Ignition Source Control Mechanical sparks & friction Open flame control Use of tools & vehicles Maintenance All require effective control of Hot Work Look for permit systems Safety & Health Consultation

Ignition Source Control Design of heating systems & heated surfaces Know your materials Minimum Ignition Temperature (MIT) Maintain temperature controls Moisture content may be critical Safety & Health Consultation

Primary Applicable OSHA Standards 1910.22 General – Housekeeping 1910.307 Hazardous (Classified) Locations 1910.178 Powered Industrial Trucks 1910.263 Bakery Equipment 1910.265 Sawmills 1910.272 Grain Handling General Duty Clause Safety & Health Consultation

NFPA Standards – Dust Hazards 61 Agriculture 68 Deflagration Venting Systems 69 Explosion Prevention Systems 70 National Electric Code 77 Static Electricity 85 Boiler and Combustion Systems 86 Ovens and Furnaces 91 Exhaust Systems Safety & Health Consultation

NFPA Standards Electrical & Systems 484 Combustible Metals Includes Magnesium, Titanium, Zirconium, Aluminum, Tantalum and other reactive metals 499 Classification of Combustible Dust 654 manufacturing, Processing and Handling of Combustible Particulate Solids 655 Sulfur 664 Wood and more Safety & Health Consultation

Viewing NFPA Standards www.nfpa.org Point to “Codes and Standards” Click “Document List” Click on standard desired, NFPA XXX On bottom, click “Preview this Document” Below disclaimer, click “I Agree” Click “Open NFPA XXX” After standard opens, the “1-2-3” button gives you the Table of Contents Safety & Health Consultation

So What Should I Do? Evaluate your workplace for the 5 points of the explosion Pentagon: a) Combustible Dust b) Ignition Source c) Confinement d) Dispersion e) Oxygen in Air/Oxidizers Safety & Health Consultation

How? a) Combustible Dust – Do you see “dust” in your workplace that is used in your process or is a by product of your process (i.e. At a sawmill sawdust is a by product of the cutting of logs/boards into product) b) Ignition Source -eliminate any possible sources of ignition, from electricity to static electricity - a minimum of Class II electrical features Safety & Health Consultation

How? c) Confinement – This will depend on the configuration of the workplace and can be difficult to eliminate d) Dispersion - keep dust from suspension in air Use dust collectors When cleaning do not re-suspend accumulated dust in air (DO NOT use air to “clean” surfaces) Safety & Health Consultation

How? e) Oxygen in Air/Oxidizers Oxygen in the air cannot be eliminated (unless workers are in SCBs) Oxidizers, if present for process, should be isolated or replaced Safety & Health Consultation

So What Should I Do? DO NOT DELAY If you find that you do have the five elements or you know you have four and may not be quite sure about number 5 – DO NOT DELAY Seek assistance We don’t want your site to look like this! Safety & Health Consultation

If you have questions about this presentation call the Delaware Office of Safety and Health Consultation at 302-761-8219. If you have questions about our free Safety and Health Consultations Please call us at 302-761-8219. Safety & Health Consultation

Post Script -Five weeks later at another Imperial Sugar plant: Safety & Health Consultation

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So sometimes it’s not just a little dust It’s a really fast way to demo a building Safety & Health Consultation