DSS155: Five Common Questions About NFPA 652, Part 1

In this episode of the Dust Safety Science podcast, we review five common questions about NFPA 652. This topic originates from a presentation that Dr. Chris Cloney recently gave as part of the NFPA 125th Annual Conference Series. This year’s theme is ‘Keeping Hazardous Environments Safe,’ so He spoke about the hazards of combustible dust, highlighted NFPA 652 compliance requirements, and answered many questions, some of which will be covered in this two-part series.

In this episode, we answer the following questions:

What problem does NFPA 652 solve?
What is NFPA 652 and how is it structured?
Does NFPA 652 apply to you?

In next week’s episode, we’ll move on to four common challenges with the implementation of NFPA 652. We’ll also review what the DHA process looks like and provide the definition of a qualified person.

What Problem Does NFPA 652 Solve?

The answer to this question can be highlighted by looking at a couple of incidents involving combustible dust.

The first occurred at Imperial Sugar in Savannah, Georgia, in 2008. A clog occurred in an enclosed tunnel underneath a silo, leading to an explosion that propagated through the tunnel and bucket elevators and caused subsequent secondary and tertiary explosions throughout the facility due to high levels of fugitive dust accumulation. Fourteen workers in total were killed.

In Episode #78, we covered a grain dust explosion in an attrition mill. The employees had turned off the system and cleaned it out, but when they started it up, a deflagration occurred, propagating through ducting several stories to the top of the building and to a cyclone, back several hundred feet into the dust collector. They had a very large explosion inside the dust collector then. The dust collector was vented as per NFPA guidelines, but this type of explosion was different. There was also no visible fugitive dust in this facility: all of the explosions were inside of equipment.

The purpose and goal of NFPA 652 is to give a structured process for:

Identifying hazards
Making recommendations on how to improve those hazards and their safeguards moving forward
Tracking progress

With so many disparate challenges, NFPA 652 provides a single framework for addressing them.

What is NFPA 652 and How Is It Structured?

NFPA 652 is the standard on the fundamentals of combustible dust. There are individual NFPA standards for grain dust, wood processing, and other applications and materials, but 652 provides the framework for tackling the challenge of combustible dust.

The standard is broken down into several chapters, but the how-to guidance really begins with Chapter 4, which is on general requirements and outlines the responsibilities of owners and operators. They include determining the explosibility and combustibility of materials and identifying any fire, flash fire explosion hazards. Other chapters are as follows:

Chapter 5- Hazard identification. It essentially asks two questions: Do you produce, generate or handle a potentially combustible dust? And have you determined the combustibility or explosibility of that dust? And if you have not, then this chapter tells you how to do that.
Chapter 6- Performance-based design. Every workplace with explosive dust hazards must use performance-based design. These standards include passive systems such as explosion venting, flameless venting, passive float valves, backdraft dampers, and flame front diverters.
Chapter 7- Dust hazard analysis. It provides the requirements for performing a DHA. In 7.2.1 – Overview, it says that a DHA shall evaluate the fire, deflagration and explosion hazards and provide recommendations to manage those hazards in accordance with Section 4.2.
Chapter 8- Management systems. This includes management of change to ensure ongoing safety in facilities handling combustible dust.
Chapter 9- Hazard management, mitigation and prevention approaches. This chapter points out to all the commodity-specific standards, and the how-to standards for combustible dust.

Does NFPA 652 Apply to You?

The 2018 version of the IFC states that the owner and operator of a facility with operations that manufacture, process, blend, convey, repackage, generate or handle potentially combustible dust or combustible particulate solids shall be responsible for compliance with the provisions of the Code and NFPA 652.

In the next section, it says the requirements of NFPA 652 apply to all new and existing facilities and operations with combustible dust hazards. Existing facilities shall have a dust hazard analysis completed in accordance with Section 7.1.2 of NFPA 652.

As states and local jurisdictions adopt the model IFC either directly or by reference, these requirements will come into play. Right now there are a handful of states that are already using the 2018 version of the International Fire Code but as the other states get moved up to 2018, they’ll start to inherit this requirement for a DHA to be completed.

OSHA also has standards related to combustible dust. 1910.1200 is a hazard communication standard and 1910.38 addresses emergency action plans. The General Duty Clause with OSHA often gets cited with combustible dust.

There are several others: insurance companies, fire marshals, municipalities that have adopted NFPA guidelines, internal company requirements, and industry and trade association requirements are all different ways that a company may be compelled to comply with NFPA 652.

Conclusion

NFPA 652 will provide an invaluable framework for addressing combustible dust hazards, but like all relatively new standards, there are questions about its scope and application. In the next episode, we’ll delve into more of the answers.

If you have questions about the contents of this or any other podcast episode, you can go to our ‘Questions from the Community’ page and submit a text message or video recording. We will then bring someone on to answer these questions in a future episode.