Dust collectors are an integral part of many plants’ combustible dust compliance strategies. As such, dust collection companies have had to remain active in supplying dust collectors to support a customer’s combustible dust control strategy by interfacing with the customer and its experts on fire and explosion protection equipment and strategies.
What Is Currently Going on in the Industry?
The U.S. Occupational Safety and Health Administration (OSHA) has issued a National Emphasis Program and continues to communicate with most industries on the hazards of combustible dust. Since passing the combustible dust program (CPL 03-00-008) in March 2008, the agency's focused effort is targeted at reducing combustible dust risks in industrial plant settings.
OSHA has increased its regulatory attention due to three catastrophic dust explosions that resulted in 14 fatalities. The events at West Pharmaceutical, CTA Acoustics and Hayes Lemmerz resulted in the US Chemical Safety and Hazard Investigation Board (CSB) publishing a report stating dust fires and explosions in the last 25 years had resulted in 119 fatalities and over 700 injuries.
Some of the common problems OSHA sees include:
- Missing or ineffective dust control leading to housekeeping issues
- Dust collectors indoors, rather than outside as OSHA expects to see if the collectors filter combustible dusts
- No isolation on inlets and/or outlets to prevent the propagation of an deflagration to other process equipment
- Explosion vents
- Dust collectors with no vents that are filtering combustible dusts
- Dust collectors with vents that are venting to an unsafe area
We are told that when an OSHA inspector walks into a facility, housekeeping is one of the first things he/she evaluates. If a high percentage of surfaces are covered by combustible dust, OSHA inspectors take notice. The measurement that serves as a type of benchmark in the industry is 0.8 mm / 1/32 in. deep of dust.
In addition to the above items, OSHA may also evaluate ducting and piping. Inspectors may look at bonding and grounding. They may also look for ignition control efforts.
It is important to note these examples of commonly investigated items are not all inclusive when it comes to reviews of facilities. When OSHA visits facilities, the most commonly referenced standards are the NFPA standards. Know that these standards go through regular revision cycles and are updated every 4-5 years. OSHA is also in development of its own combustible dust standard, but its publication date is unknown at this time.
Often when it comes to understanding these issues and standards, customers ask for guidance in who to consult so they can know what to do to be in compliance. The first key player a customer should seek out is an Authority Having Jurisdiction (AHJ). By definition in NFPA 68, an “AHJ is an organization, office or individual responsible for enforcing the requirements of a code or standard, or for approving equipment, materials, an installation or a procedure.” A few examples of AHJs include but are not limited to: insurance inspection departments, rating bureaus, Fire Marshalls and certainly OSHA inspectors.
Since each AHJ may have a specific set of codes he or she references, you may need to have general knowledge of more than one standard or code. As a process owner, you are responsible for the selection of your combustible material management strategy. You also need to assure your process and facility comply with all applicable federal, state, and local codes and standards. Many standards and codes may influence your decisions on dust control, including the local, state, and federal regulations. Knowing the codes that apply to your facility is critical, and you should always research the code requirements in your area. Just to reiterate, a few commonly referenced standards for combustible dust risk management strategies include those issued by: National Fire Protection Association (NFPA), the International Mechanical Code, the International Fire Code, Factory Mutual Property Loss, and OSHA (federal). Since these standards are often cited by OSHA, and have been adopted as code in many areas of the country, they may be a good starting point for consideration in developing your combustible dust management strategy. For more free information visit www.nfpa.org.
Why Dust Collectors Should Be Part of Your Strategy Decision
Many process requirements make elimination of combustible dust, mist, or fume impractical. However, it may still be very possible to manage the dispersion of dust within your plant by using an appropriate and effective industrial ventilation system including dust collection. A well designed, maintained, and operated industrial ventilation system including good hoods, proper duct sizes, and properly selected collection equipment can provide effective dust control and can therefore help manage the presence of dispersed dust. This not only reduces housekeeping frequency and expense, but also may help you reduce the risk of dust explosions in your facility, particularly the destructive secondary explosions, by helping reduce the presence of dispersed fuel in your facility.