Protecting Workers from Combustible Dust with FR Clothing June 2010
Agenda Introduction: Combustible Dust & OSHA What is Combustible Dust? Combustible Dust Statistics Case Studies Hazard Analysis Mitigation Strategies FR Clothing: Background FR Clothing Can Protect t Workers Conclusion: Preventing and Protecting Against Combustible Dust
Combustible Dust: Background Nearly 300 explosions have injured or killed over 800 workers since 1980. Imperial Sugar Plant explosion in 2008 caused OSHA to re-intensify a National Emphasis Program targeting the hazard. OSHA has cited over 1,000 firms for combustible dust. Of firms visited, 87% have received citations. As yet, there is no enforceable standard to regulate combustible dust. The complexity of the combustible dust hazard poses a challenge to standard-makers.
What is Combustible Dust? There is no widely accepted definition of combustible dust. OSHA defines combustible dust as: organic or inorganic dust particles that are finely ground and pose a deflagration or other fire hazard when suspended in air or another oxidizing medium over a range of concentrations. Combustible Dust can consist of any material and varies in the dangers of its explosivity.
How does dust combust? Finely divided dust is disturbed from its resting position and suspended in the air or introduced to another oxidant. Ignition sources such as static, a spark, an ember, a hot surface, friction heat or flame come in contact with dispersed dust, causing an explosion.
5 Elements of an Explosion
Vulnerable Industries
Common Combustible Dusts
Known Injuries & Deaths Over Time
OSHA is Acting OSHA is working to create a Combustible Dust Standard applicable to a variety of industries. HR 849, requiring a combustible dust regulation from OSHA following the 2008 Imperial explosion, was passed but never signed into law. OSHA is targeting dozens of industries, including refineries, chemical companies, and petrochemical companies, and delivering citations at a rate of 87%. An estimated 100,000 companies are at risk! Go to OSHA.gov to keep up with the latest rulings.
Combustible Dust Fines As part of its National Emphasis Program, OSHA is targeting industries with a known combustible dust hazard. The following are fines issued recently by OSHA for combustible dust: Plastics Manufacturer $133,500 Log Manufacturer $215,000 Ohio LLC $472,900 Food Processor $1.1M Imperial Sugar $8.8M (Largest fine in OSHA history!) y)
Current OSHA Dust Standards Some industry-specific standards already exist but are not comprehensive. 1910.22(a)(1) Housekeeping, allowable dust accumulations 1910.22(a)(2) Housekeeping, allowable dust accumulation on floors 1910.178(c) Classification in hazardous environments 1910.307 Hazardous Locations 5(a)(1) General Duty 1910.272 Grain Handling Standard
Current NFPA Dust Standards NFPA 68 Guide for Venting of Deflagrations NFPA 85 Boiler and Combustion Systems Hazards Code NFPA 69 Standard on Explosion Prevention Systems NFPA 499 Classification of Combustible Dusts NFPA 654 Prevention of Dust Explosions from Manufacturing Processing, and Handling of Dust NFPA 61 Prevention of explosions in agricultural and food processing facilities NFPA 484 Metal Dust Standard NFPA 664 Wood Dust Standard
Challenges of Combustible Dust Combustible dust, as a flash fire hazard, is highly unpredictable. Dust can collect in a wide variety of materials and consistencies. Even two scenarios with the exact same type, volume and density of dust, ventilation source, and ignition source may produce entirely different explosions at different times. Practical and cost-effective mitigation strategies can significantly diminish the possibility of an explosion at your firm, including the use of flame resistant clothing.
What Can Be Done? Multi-step safety processes will help to ensure that combustible dust is mitigated. Dust testing, adequate housekeeping, communication, training, and use of personal protective equipment (PPE) can all be used to ensure that combustible dust is kept at bay. No mitigation strategy will ensure that dust will be 100% prevented. It is safest to follow as many precautions as possible.
Hazard Analysis by Lab Testing Though hazard assessment under these circumstances is difficult at best, testing ti for dust explosiveness is both possible and practical. No enforceable, set method for conducting hazard analysis. Dust can be tested for a general NFPAclassified KST number to estimate the anticipated behavior of dust deflagration, or explosion. KST testing may be a good way to assess combustible dust hazard.
What does KST mean? When a facility opts to have testing performed, the following are analyzed: 1. Minimum Dust Concentration 2. Minimum Ignition Temperature 3. Minimum Ignition Energy KST is a generalized number used to estimate the anticipated behavior of dust deflagration, or explosion.
How is KST Testing Conducted? Bulk samples of dust material in plastic bottles between 2-2.5 lbs are tested for a general NFPA-classified KST number. Samples of dust are taken from several locations, such as ceilings, ductwork, and corners. Labs assess the above factors to analyze the KST number, or a dust s approximate explosive power and explosive probability.
KST Categories & Explosiveness EXPLOSION CLASS ST 0 KST Characteristic 0 No explosion ST 1 >0 and 200 Weak Explosion ST 2 >200 and 300 Strong Explosion ST 3 >300+ Very Strong Explosion
Common Dusts & KST Values Common Dusts KST Value Aluminum Powder 400 Barley Grain Dust 240 Charcoal 117 Cotton 24 Magnesium 508 Soap 111 Sulphur 151 Tobacco 12 Wood Dust 102
Case Studies
Combustible Dust Case Studies Year Facility Statet Dust Killed Injured Reasons s for Explosion 1999 Iron Casting Foundry MA Phenolic Resin 3 9 Inadequate housekeeping, Poor ventilation, Poor oven maintenance, Inadequate safety equipment 1999 Electrical Generation MI Coal Dust 1 14 Lack of worker awareness, Inadequate housekeeping 2002 Rubber Recycling MS Scrap Tire Grindings 5 6 Lack of worker awareness, Improper building construction ti
Combustible Dust Case Studies Year Facility State Dust Killed Injured Reasons for Explosion 2003 Rubber Drug Products NC Polyethylene 6 38 No hazard assessment, No hazard communication, i Poor engineering 2003 Fiberglass Insulation 2008 Sugar Refinery KY Phenolic Resin 7 37 GA Sugar 14 36 No hazard assessment. No hazard communication, Poor building design Poor equipment design, Inadequate housekeeping, Dust accumulated over MEC
Malden Mills (MA)
Ford River Rouge (MI)
Rouse Polymerics (MS)
West Pharmaceutical (NC)
Rubber Dust Explosion at West
CTA Acoustics (KY)
Imperial Sugar (GA)
Imperial Sugar Incident
Weak Explosions? How explosive was the dust at the above facilities? Phenolic Resin: 129 Coal Dust: 129 Polyethelyne: 134 Sugar Dust: 138 Tire Grindings: 139 All of these industries were ST Category 1: Weak Explosion, yet all six explosions resulted in significant damage, injury, and worker death.
Mitigation Strategies
Mitigation: Communication is Key Workers are always the first line of defense in preventing and mitigating fires and explosions. If the people closest to the source of the hazard are trained to recognize and prevent hazards associated with combustible dust in the plant, they can be instrumental in recognizing unsafe conditions, taking preventative action, and/or alerting management. (OSHA, 2005). Perhaps the most important component of hazard mitigation is raising employee awareness.
Mitigation: OSHA Recommendations OSHA recommends guarding against the following: Materials that can be combustible when finely divided Processes which use, consume, or produce combustible dusts Open areas where combustible dusts may build up Hidden areas where combustible dusts may accumulate Means by which dust may be dispersed in the air Potential ignition sources
Mitigation: NFPA Recommendations Minimize 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. i Inspect for dust residues in open and hidden areas, at regular intervals, Clean dust residues at regular intervals. Use cleaning methods that do not generate dust clouds, if ignition sources are present.
FR Clothing: Additional Protection No mitigation strategy will provide 100% protection against a combustible dust explosion for an at-risk firm. Choosing flame resistant clothing is an effective method to protect at-risk employees if primary mitigation strategies are economically or practically ineffective and even if primary mitigation strategies are effective and employers want to prevent or minimize worker injury.
FR Clothing Reduces Injury Where any flash fire hazard exists, using flame resistant clothing is a common-sense method to significantly reduce the chance of worker injury in the event of an explosion. On top of preventing the added burn injury inherent in the melting and dripping of nonflame resistant fabrics, the cost of flame resistant clothing is minimal compared to the devastation of a burn injury on a worker personally and economically.
FR Clothing: Voluntary Protection Though flame resistant clothing is not yet required for workers exposed to flash fire hazards, its procurement may be the last and most important t step a company can take to insure the lives of workers. Many companies exposed to flash fire have already taken this preventative measure to avert worker injury, especially in the refinery industry. OSHA may require FR clothing in its combustible dust ruling.
FR Industry Comparison Electric Refinery Combustible Utility Dust Hazard Arc Flash Flash Fire Flash Fire Relative Accuracy of Hazard Analysis OSHA Regulated High Low Low Yes Maybe* (New interp of OSHA 1910.132 may require FR as of March 2010) No Use of PPE High High Low Mitigation Simple Complex Complex Strategies
The Statistics: FR Works! The most serious injuries typically y occur AFTER the flash fire, from non-fr fabric burning against the skin. Non-FR clothing burns and melts against the skin, increasing the risk of injury. Flame resistant clothing self-extinguishes extinguishes once the source of heat is removed. Until there is a unified, enforceable standard regarding this hazard, voluntary compliance with the current recommendations is necessary to ensure worker safety.
Flash Fire Incident Video
FR Clothing Requirements All flame resistant clothing must be tested for safety and durability. NFPA 2112 is the best FR Clothing standard to address flash fire hazards such as combustible dust. NFPA 2112 says that flame resistant clothing must protect the wearer by, not contributing to the burn injury of the wearer, providing a degree of protection to the wearer, and reducing the severity of burn injuries resulting from accidental exposure to hydrocarbon flash fires.
Tests for FR in NFPA 2112 The Vertical Flame Test determines whether a fabric will continue to burn after the source of ignition is removed. The Three-Second Manikin Test is the test method for evaluating a garment s flame resistance using an instrumented manikin. A garment is exposed to a heat flux of 2.0cal/cm2.sec for three seconds. If the garment displays less than 50% total body burn, the fabric achieves a passing performance. The Thermal Protective Performance test (TPP). The 2007 edition of NFPA 2112 requires the Thermal Protective Performance test to be performed both with the fabric against the sensor and with a ¼ spacer.
Arc Flash Parallel: Proven Protection In the 1970s, before OSHA required utility workers to wear flame resistant clothing, an average of 9.5 burn accidents and 14.7 burn injures per 100 workers resulted in devastating personal and economic costs to utilities. After OSHA implemented 1910.269, the Standard for electric generation, transmission, and distribution in the 1990s, worker burn injury rates in the 2000s decreased to 4 accidents and 6.2 injures per 100 workers.
NFPA 654-2011 Operators shall wear flame-resistant garments as specified in NFPA 2113 and any other personnel protective equipment required for protection against flash fire hazards during charging operations Operating Plans shall include the use of flame-resistant garments as specified in NFPA 2112 for all exposed personnel when the design dust mass / accumulation exceeds the threshold value determined per section 6.1 Operating and maintenance procedures shall address personal protective equipment (PPE) for tasks involving or handling of combustible dust according to the following: PPE shall include flame resistant garments in accordance with the workplace hazard assessment required by NFPA 2113: and, Where a dust explosion hazard or flash fire hazard exists, flame resistant garments shall be required for all exposed personnel.
What Next? OSHA is Acting! OSHA will most likely consult current NFPA standards d in its future combustible dust regulation. Hefty fines will continue to be delivered for various violations of existing standards, especially the General Duty Clause. OSHA may require FR clothing as part of its regulation. Voluntary adaption of known mitigation strategies will result in avoiding fines, maintaining productive working conditions, and keeping workers safe until the ruling is finalized.
Mitigation Strategies: Summary Company-wide hazard communication and training i is key. Proper housekeeping, such as using a dust vacuum to collect dust Proper building engineering (i.e. ensuring that dust cannot accumulate in unmonitored areas) Proper ventilation systems Removal or careful monitoring of potential ignition sources Use of personal protective equipment, such as FR clothing, as a last line of defense
Last Line of Defense Flame resistant clothing is a secondary protective strategy providing protection from momentary burns and flames. FR has been proven a cost-effective and successful measure for employers to take in protecting their employees from thermal hazards in other industries. Even companies that implement all known mitigation strategies will find that cost- effective flame resistant clothing will offer peace of mind in the event that an explosion does occur.
Want to learn more? Sign up now for more information about: Combustible Dust Mitigation Strategies t Current Standards OSHA Activity FR Clothing Tyndale will send you an email very soon with these resources so that you can learn more about this insidious hazard!
Questions? Thank you for the opportunity to meet with you today! Rob Whittenberger, President Tyndale Company, Inc. RWhittenberger@Tyndaleusa.com