Feb 2021

Combustible Dust Hazard Analysis (DHA)

What Is A Dust Hazard Analysis?

As defined in NFPA 652, Standard on the Fundamentals of Combustible Dust (2019 edition), a Dust Hazard Analysis (DHA) is a systematic review to both identify and evaluate the potential fire, flash fire, or explosion hazards associated with the presence of one or more combustible particulate solids in a process or facility.

NFPA 652 provides specific details regarding the DHA requirements in Chapter 7. 

In general, a DHA should include the following:

  • Identification and Evaluation of the process or facility areas where fire, flash fire, and explosion hazards exist (i.e., where do combustible dust hazards exist within the process or facility and what is the risk / exposure).
  • Where such a hazard exists, Identification and Evaluation of specific fire and deflagration scenarios.
    • Identification of safe operating ranges
    • Identification of the safeguards currently in place to protect the facility or process from fire, deflagration, and explosion events.
    • Recommendation of additional safeguards where warranted, based on NFPA standards / guidelines and industry best practices.

NFPA 652 includes an example of how a DHA should be performed in Annex B. 

Why should your facility consider a DHA?

For facilities/processes that handle dust, the owner/operator of that process is responsible to determine if the dust handled poses a combustible dust fire or explosion hazard.  NFPA 652 requires that all combustible dust users complete a DHA for existing systems. The deadline for completing initial DHAs for most facilities was 5 years after the effective date of the first edition (2015) of NFPA 652, which was September 7, 2020.

It is the responsibility of the owner/operator to complete a DHA for:

  • All new processes
  • Any changes to existing processes
  • All existing processes/facilities (retroactive) regardless of when the facility was constructed.

In addition, the standard requires reviewing and updating DHAs every 5 years.

Risk Logic’s engineers have the specialized knowledge of combustible dust hazards needed to analyze the hazards in your facility.  Our engineers will visit your facility to evaluate the receiving, storage, use, processing and disposal of all combustible dusts. 

Our engineers will:

  • Evaluate combustible dust handling, generating and fugitive dust control operations at a facility.
  • Evaluate processes and equipment to identify potential failure modes and ignition sources.
  • Document the locations and severities of fire, flash fire, and dust explosion hazards.
  • Evaluate existing fire/explosion suppression systems, warning devices and onsite extinguishing capabilities
  • Provide recommendations designed to reduce risk of fire and explosion.

In addition, we will evaluate human element programs relating to combustible dusts, including:

  • Staff training
  • Ignition source control
  • Contractor management
  • Housekeeping
  • Testing and maintenance of manual/automatic passive and active protection systems

The finished DHA document will be highly customized and tailored to the exact operations, protection features, testing/maintenance programs, and human factors present at the site.

An extensive sample combustible dust checklist is provided in Annex F of NFPA 61, Standard for the Prevention of Fire and Dust Explosions in Agricultural and Food Processing Facilities, (2020 edition), and provides an excellent basis for discussion while our engineers are on site.

If you would like to schedule a DHA at your facility, please contact Risk Logic.


NFPA 652, Standard on the Fundamentals of Combustible Dust (2019 edition)

NFPA 61, Standard for the Prevention of Fire and Dust Explosions in Agricultural and Food Processing Facilities, (2020 edition)