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published on

January 2024

Aerial view of a paper mill facility. Paper mills are a common example of a facility with combustible dust hazards

What is the New NFPA 660 Combustible Dust Standard About?

Sooner rather than later, the new NFPA 660 Combustible Dust Standard will take effect and significantly impact industrial facility owners and operators. NFPA 660 will consolidate all existing combustible dust standards into a single streamlined document. In theory, it will lead to increased site safety and reduced standard conflicts.

But what is NFPA 660, what does it mean for the industry at large, and when will it go into effect? Read on to learn the answers to these questions and related topics.

explosion demo

What are the NFPA Combustible Dust Standards?

Current industry standards from the National Fire Protection Association (NFPA) outline appropriate operational and safety guidelines for a variety of possible hazards. The NFPA combustible dust standards specifically relate to combustible dust dangers, including fires, flash fires, explosions, and more.

The NFPA combustible dust standards include:

  • NFPA 652 – Standard on the Fundamentals of Combustible Dust
  • NFPA 61: Standard for the Prevention of Fires and Dust Explosions in Agricultural and Food Products 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
  • NFPA 655: Standard for Prevention of Sulfur Fires and Explosions
  • NFPA 664: Standard for the Prevention of Fires and Explosions in Wood Processing and Woodworking Facilities

These standards are widely used around the world and are vital for industrial facilities of many different types to ensure workplace safety. NFPA 652 is the “umbrella” standard that provides fundamental guidance on managing combustible dust hazards regardless of industry. NFPA 652 then directs the reader to the “commodity-specific” standards that focus on specific requirements for certain materials or products as a function of individual industries.

NFPA combustible dust standards are crucial because the Occupational Safety and Health Administration (OSHA) – alongside other regulatory agencies – uses them to guide and enforce safety compliance at work sites and facilities. For example, OSHA may invoke the General Duty Clause and refer to NFPA combustible dust standards to enforce worksite safety if a facility is caught violating said standards.
As experts in process safety and hazard analysis, BakerRisk is on many committees responsible for developing the above combustible dust standards, as well as the new NFPA 660 standard.

explosion tower demo

NFPA 660 Explained

NFPA 660 will be an “all-encompassing” new combustible dust standard that will combine the existing NFPA 652 standard along with the “commodity-specific” combustible dust standards. Over the past two years, NFPA 660 committee members have identified the fundamental content from each current standard and aligned that content with more industry-specific elements.
The result: a superior and more comprehensive combustible dust standards document.

By consolidating legacy information, NFPA 660 will ensure that relevant and effective guidelines, recommendations, and best practices are all in the same location for easier access to this information. In doing this, facilities and worksites will be able to browse one standard to learn how to handle combustible dusts instead of looking through several. The hope is that this will reduce confusion and eliminate conflicting information found in existing standalone standards.

NFPA 660 – Changes to Combustible Dust Standards

NFPA 660 will be a consolidating and clarifying document, not a massive change to existing combustible dust standards or practices. Most facility owners or operators do not need to worry about revamping their current combustible dust safety procedures from the ground up. For instance, facility operators will still need to perform a Dust Hazard Analysis (DHA) and revalidate every five years.

Will There be Changes to Dust Collection or Dust Monitoring?

NFPA 660 won’t include major changes to dust collection system design or housekeeping requirements. But if you work with BakerRisk, you may already have a superior solution in our proprietary Dust Accumulation Monitor! Here’s BakerRisk team member Phil Parsons with more on how the Dust Accumulation Monitor works and its value to facilities:

“Current National Fire Protection Association (NFPA) standards place significant emphasis on the need to maintain housekeeping of dust accumulations outside of equipment to below different threshold thicknesses to minimize the associated risk. A common reference point for invoking a potential hazard is when a dust accumulation is sufficiently thick to prevent the underlying surface color from being distinguished. This puts a significant demand on facility staff and resources to periodically visually inspect elevated surfaces of a process facility, particularly if the process building volume is large or very tall. Inspections may involve the use of man-lifts, cranes, and a team of devoted personnel, resulting in a significant cost burden.

The need for a system capable of efficiently and automatically monitoring dust accumulations in a facility, maintaining safe working conditions, and, in turn, efficiently deploying housekeeping resources became evident to our team. Enter the BakerRisk Dust Accumulation Monitor! Our patented design automates the monitoring process with a system of monitors designed to detect dust levels in various locations. These monitors communicate with each other and send an alert to a central monitor. If dust accumulation exceeds acceptable levels, the Dust Accumulation Monitor will alert facility personnel via the central monitor. Contact us to learn more about this solution!”

Graphic of a combustible dust incident.

Why is NFPA 660 Necessary?

At its core, NFPA 660 will be a beneficial, arguably necessary update to the current collective combustible dust standards. Why?
Broadly, NFPA 660 should lead to fewer combustible dust incidents or hazards. NFPA 660 will help all affected organizations to follow the same set of safety practices. Consolidating all the standards into one set of rules will simplify those practices, minimize the potential for misunderstandings, and make the standards more applicable and accessible to worksites.

More specifically, the benefits of NFPA 660 will include:

  • Reduced redundancy. NFPA 660 will remove repeated information found in multiple standards.
  • Consistent wording. NFPA 660 will ensure that the same terms and relevant definitions are applied throughout.
  • Applicability to more facilities/use cases. NFPA 660’s refined standards will have more universally applicable requirements and guidelines for equipment, procedures, etc.
  • Schedule update improvements. Consolidating combustible dust standards will allow all of them to be updated together instead of being updated at different times.

Dust Collectors at an industrial facility

When will NFPA 660 be Released, and Can You Review It?

As of December 2023, NFPA 660 is available for public comment and input on its second draft. The committee for developing NFPA 660 – of which BakerRisk is a part – will meet to vote on public comments in March 2024. If you’re interested in the exact wording of the new combustible dust standards or want to contribute, you can download NFPA 660 here.

The NFPA 660 committee will submit the finalized version of the document to the NFPA Standards Council in August 2024. Once it’s approved, NFPA 660 will go into effect in late 2024 or early 2025, depending on whether changes are made.


To recap, NFPA 660 will be a consolidating and streamlined collection of existing NFPA combustible dust standards. Once finalized, it will represent a modernized, updated version of universally applicable combustible dust standards for all relevant facilities and worksites.

As one of the key contributors to NFPA 660’s conception and development, BakerRisk is exactly who you should contact if you have further questions about best practices for managing combustible dust hazards, training courses, Dust Hazard Analysis services, and more. We can also show your worksite and staff what to do before completing a Dust Hazard Assessment. Contact BakerRisk today to learn how we can serve your facility needs.