The National Fire Protection Association (NFPA) is charged with creating standards for fire prevention in North America. While they have no enforcement power of their own, Authorities Having Jurisdiction (AHJs), including OSHA, will reference the NFPA standards in their own regulations. NFPA has had industry/commodity specific standards for combustible dusts for years, in some cases dating back to the early 1920’s. These include:
- NFPA 61: Standard for the Prevention of Fires and Dust Explosions in Agricultural and Food Processing Facilities;
- NFPA 484: Standard for Combustible Metals;
- NFPA 654: Standard for the Prevention of Fire and Dust Explosions from the Manufacturing, Processing, and Handling of Combustible Particulate Solids; and,
- NFPA 664: Standard for the Prevention of Fires and Explosions in Wood Processing and Woodworking Facilities.
These industry standards have not been consistent with each other, providing differing definitions, procedures, and requirements. In the fall of 2015, NFPA released NFPA 652: Standard on the Fundamentals of Combustible Dust. This was an important first step for creating a single overarching standard for dealing with fire and explosion hazards associated with combustible dusts of all types and in all industries. Notable requirements from NFPA 652 include:
- Procedures for sampling and testing of dusts for combustibility and explosibility; and,
- Conducting a Dust Hazard Analysis (DHA) at facilities handling combustible dusts within 3 years of issuance of the standard.
As part of the development of NFPA 652, NFPA founded the Correlating Committee on Combustible Dusts to oversee the individual combustible dust Technical Committees. The primary function of this Committee is to work to align the industry/commodity specific standards to avoid the confusion that has plagued these standards.
The summer of 2016 has seen the release of the 2017 revisions for NFPA 61, 654, and 664. These are the first industry specific standards to be revised since founding the Correlating Committee on Combustible Dusts. As such, numerous changes have been made to these standards to begin the process of aligning the industry standards to NFPA 652. This included updating definitions across all three of the standards and referencing specific requirements of NFPA 652. This includes incorporation of the requirement for conducting the DHA; however, both NFPA 61 and NFPA 654 modified the timeline to 5 years for completion, instead of 3 years. The major updates to these standards are summarized in the paragraphs below.
NFPA 61: Standard for the Prevention of Fires and Dust Explosions in Agricultural and Food Processing Facilities, 2017 edition
The 2017 revision to NFPA 61 sees significant modifications from previous editions of the standard. This standard now incorporates all of NFPA 652 into NFPA 61. The Technical Committee made this update such that users of NFPA 61 would not need to use NFPA 652 as a starting point. Other notable updates include:
- The exemption from protection and monitoring devices on small, low speed bucket elevators has been removed from the standard.
- Flame-arresting and particulate retention vent systems are now explicitly allowed to be utilized for explosion venting on bucket elevators.
- Exceptions on explosion protection for smaller cyclones are now provided, with certain conditions.
NFPA 654: Standard for the Prevention of Fire and Dust Explosions from the Manufacturing, Processing, and Handling of Combustible Particulate Solids, 2017 edition
The 2017 revision to NFPA 654 was not drastically altered like NFPA 61. Instead, NFPA 654 opted to align its definitions to match those of NFPA 652 and incorporates references, where applicable. This includes an Owner’s Obligation statement that the facility owner/operator is responsible for ensuring the facility meets the requirements of NFPA 654 and 652. Other notable updates include:
- Like NFPA 61, the protection and monitoring exemptions for smaller bucket elevators have been eliminated;
- The allowable airflow handling capacity for enclosureless dust collectors has been increased from 3,000 CFM to 5,000 CFM;
- Clarification has been provided that flame-arresting and particulate retention vent systems cannot be used as an isolation device in a return air line; and,
- Procedures for vehicles in classified locations that are not addressed in NFPA 505: Fire Safety Standard for Powered Industrial Trucks Including Type Designations, Areas of Use, Conversions, Maintenance, and Operations have been added.
NFPA 664: Standard for the Prevention of Fires and Explosions in Wood Processing and Woodworking Facilities, 2017 edition
Like the 2017 revision to NFPA 654, the revision to NFPA 664 was not drastically altered and, instead, opted to align its definitions to match those of NFPA 652 and incorporates references, where applicable. This also included an Owner’s Obligation statement that the facility owner/operator is responsible for ensuring the facility meets the requirements of NFPA 664 and 652. Other notable updates include:
- Increased clarification on the application of NFPA 664 to woodworking operations/carpenter shops that exceed certain sizes has been added;
- The identification of a deflagration hazard applying to locations with 1/8 inch of dust accumulation over 5% of an area now specifically only apply to “small areas”. No area limit is specified for larger spaces, though now an option is present to define deflagration hazards using the DHA per NFPA 652;
- The separation/segregation of hazardous locations from NFPA 652 has been incorporated.
- Increased clarification has been added on the use of enclosureless dust collectors.
- The chapters addressing human element and housekeeping are now specifically identified as being applied retroactively.
- The PPE and Workplace Hazard Assessment requirements from NFPA 652 have been incorporated, which includes requirements for flame-resistant clothing.
While not specifically related to the standards previously discussed, the 2017 edition of NFPA 499: Recommended Practices for the Classification of Combustible Dusts and of Hazardous (Classified) Locations for Electrical Installations in Chemical Process Areas was also recently issued. This is a useful standard when conducting a DHA. More information on this update can be found on our blog: https://www.conversiontechnology.com/nfpa-issues-2017-edition-nfpa-499/
For more information on NFPA 652 and on conducting a DHA, see the Compliance Matters Newsletter – Summer Q3 2015, available at https://www.conversiontechnology.com/resources/
If you need assistance conducting a Dust Hazard Analysis or have questions about how these NFPA updates affect your facility, please do not hesitate to contact CTI.