OSHA initiated its Combustible Dust National Emphasis Program (NEP) on October 18, 2007, to inspect facilities that generate or handle combustible dusts that pose a deflagration/explosion or other fire hazard.
Combustible dusts are fine solid particles that present a flash fire or explosion hazard when suspended in air. More than 70% of the dusts handled in the industry are considered to be combustible dusts. A dust explosion can result in damaged equipment, downtime, injuries, and even fatalities. Companies that don’t recognize these risks are posing a serious threat to the safety of their employees.
Many materials can become combustible under specific situations. Dusts that behave in this manner include:
The best way to prevent dust fires and explosions at your facility is to keep the workplace as dust free as possible. Some things to focus on to improve dust collection at your facility are:
Industrial vacuum systems are commonly used for cleaning and maintenance and are an indispensable tool for the recovery of combustible dust. However, when considering an industrial vacuum system for the recovery of combustible dust, several; safety factors must be considered such as potential flammability and dust ignition potential.
How to choose the right Hazloc Vacuum System for the recovery of combustible dust?
To choose the right Hazloc vacuum system for your application, you will have to identify the material to be recovered and determine the classification of the hazardous location (Hazloc) where the vacuum system will be used.
Identifying the material to be recovered
The first step in selecting the correct Hazloc Vacuum System is to identify the material to be recovered. “Dry only” vacuum systems that are designed to recover dust or dry material only. “Wet and dry” vacuum systems that are designed to recover dry material or liquids. Vacuum systems are not designed to recover mud (mixture of liquid and soil). Mud would obstruct filters and decrease the performance of the vacuum system.
Flammable materials can be gaseous, liquid or solid. To work in hazardous locations where flammable materials are present, Tiger-Vac recommends an explosion proof vacuum systems that is Legally Certified.
Classifications of Hazardous Locations According to NFPA 70
Locations shall be classified depending on the properties of the flammable gas, flammable liquid–produced vapor, combustible liquid–produced vapors, combustible dusts, or fibers/flyings that may be present, and the likelihood that a flammable or combustible concentration or quantity is present. Each room, section, or area shall be considered individually in determining its classification
Class II and Class III (Dust) locations
Class II Locations
Class II locations are those that are hazardous because of the presence of combustible dust.
Class II, Division 2
A Class II, Division 2 location is a location in which combustible dust, due to abnormal operations, may be present in the air in quantities sufficient to:
Class III Locations
Class III locations are those that are hazardous because of the presence of easily ignitable fibers or where materials producing combustible flyings are handled, manufactured, or used, but in which such fibers/flyings are not likely to be in suspension in the air in quantities sufficient to produce ignitable mixtures.
Class III, Division 2
A Class III, Division 2 location is a location in which easily ignitable fibers/flyings are stored or handled other than in the process of manufacture. Such locations usually include some parts of rayon, cotton, and other textile mills; combustible fibers/flyings manufacturing and processing plants; cotton gins and cotton-seed mills; flax-processing plants; clothing manufacturing plants; woodworking plants; and establishments and industries involving similar hazardous processes or conditions.
NFPA Standards used by Tiger-Vac
Tiger-Vac uses several NFPA standards as guidelines for the design and fabrication of its vacuum systems for combustible dust recovery. It is true that compliance with NFPA standards is voluntary. However, OSHA relies heavily on the NFPA when developing its own standards. And both courts of appeals and the Occupational Safety and Health Review Commission have ruled that OSHA’s main housekeeping standard, 1910.22, applies to combustible dust hazards.
NFPA 652: Standard on the Fundamentals of Combustible Dust
Every year, destructive and deadly dust-related fires and explosions affect a wide range of industries around the globe. In the United States alone, 50 combustible dust accidents occurred between 2008 and 2012. To manage the dust-related fire, flash fire, and explosion hazards in industries that use dust collection and handling equipment, or have processes that may generate combustible dust, NFPA introduces the first-time NFPA 652: Standard on the Fundamentals of Combustible Dust. This important new Standard serves a wide variety of industries including chemical, wood processing, metals, and agricultural.
In addition to providing new general requirements for managing combustible dust fire and explosion hazards, NFPA 652 directs users to NFPA's appropriate industry- or commodity-specific standards, such as NFPA 61: Prevention of Fires and Dust Explosions in Agricultural and Food Processing Facilities; NFPA 484: Combustible Metals; NFPA 654: Prevention of Fire and Dust Explosions from the Manufacturing, Processing, and Handling of Combustible Particulate Solids; and NFPA 664: Prevention of Fires and Explosions in Wood Processing and Woodworking Facilities.