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Protecting people and assets through compliance with NFPA 652

The National Fire Protection Association (NFPA) 652, Standard on the Fundamentals of Combustible Dusts, provides general requirements for the management of combustible dust fire and explosion hazards and directs the user to appropriate NFPA industry or commodity-specific standards. The standard ensures that fundamental requirements are addressed consistently across industries, processes, and dust types.

NFPA 652 - Chilworth Technology

The central component of NFPA 652 is a Dust Hazard Analysis (DHA), which is required if materials handled and processed have been identified as combustible and/or explosible. It consists of an assessment of materials and processes, an analysis of the hazards posed by these materials and processes and a hazard management plan.

Our senior process safety specialists are uniquely qualified to assess the hazards, evaluate the adequacy of existing controls, and to propose practical measures for ensuring safety of people, facility, and the community. This includes the identification of possible fire and explosion scenarios and the evaluation of existing or proposed hazard-mitigation systems and equipment. We are confident that our well-tried disciplined approach will empower our clients to attain the required life-safety and business continuation objectives and requirements.

We have been conducting specialist Dust Hazard Assessments (DHA) for more than three decades for our clients in the Americas, Europe, and the Asia Pacific region. Through our accredited laboratory testing facilities and a world-class team of senior process safety specialists with extensive applicable expertise, we are uniquely positioned to assist our clients with all the expert services necessary to be in full compliance with all the requirements of NFPA 652. This includes determining combustibility and explosibility hazards of materials, conducting a Dust Hazard Analysis (DHA), managing identified fire, flash fire, and explosion hazards, and establishing Safety Management Systems.

NFPA combustible dust analysis - Chilworth Technology

Practical approach for identifying and managing combustible dust

We provide all the services necessary for a Dust Hazard Analysis as required by NFPA 652, beginning with the identification, testing and classification of particulate solids and dusts, and concluding with a ready-to-implement safety management system. Our NFPA 652 compliance-related services include:

  • Hazard Identification – Our experts identify potential locations and situations conducive to fire, flash-fire, and explosion hazards involving fine particulate solids and dusts.
  • Laboratory Testing – We collect representative dust samples from appropriate locations using acceptable methodologies to preserve the properties of the sample which is then tested for appropriate and necessary ignition sensitivity and explosive properties in our accredited laboratories in accordance with applicable test standards.
  • Dust Hazard Analysis (DHA) – DHA is required if materials handled and processed have been identified as combustible and/or as an explosion risk. DHA is a systematic review to identify and evaluate potential fire, flash fire, and explosion hazards associated with the presence of combustible particulate solid(s) in a process or facility. DHA must be conducted by one of our experts with demonstrated ability to deal with hazards related to processing and managing combustible particulate solids.
  • Dust Hazard Management – According to NFPA 652, the owner/operator of a facility with potentially combustible dust shall be responsible for managing identified fire, flash fire, and explosion hazards. Consideration shall be given to building and equipment design, equipment design, housekeeping, ignition source control, personal protective equipment, dust control, explosion prevention / protection / Isolation, and fire protection. If the prescribed approaches of NFA 652 for the management of combustible dust hazards are found to be impractical then a documented risk assessment shall be permitted to be conducted in accordance with life safety requirements.
  • Safety Management Systems – NFPA 652 requires that the owner/operator shall establish written management systems for operating its facility and equipment to prevent or mitigate fires, deflagrations, and explosions from combustible particulate solids. NFPA 652’s management system requirements shall apply to new and existing facilities and processes.

Learn more about the requirements and timeline for compliance with NFPA 652.

Questions and answers about our NFPA 652 services

We are uniquely positioned to help our clients be in complete, effective, and sustainable compliance with all the requirements of NFPA 652. We have collected some frequently asked questions and answers about NFPA 652 and its requirements. Please contact us for more information!

What is the intent of the new standard NFPA 652?

Its intent is to provide general requirements for the management of combustible dust fire and explosion hazards and to direct the user to appropriate NFPA industry or commodity-specific standards. Additionally, it establishes relationships and hierarchies with industry or commodity-specific standards to ensure that fundamental requirements are addressed consistently across industries, processes, and dust types.

Which tests are typically performed during the laboratory testing phase?

If the dust is found to be combustible/explosible in the Go / No Go Screening then depending on the situation some of the following tests will need to be considered:

  • Maximum Explosion Pressure (Pmax) and Deflagration Index (Kst)
  • Minimum Explosible Concentration
  • Limiting Oxygen Concentration
  • Minimum Ignition Energy
  • Minimum Ignition Temperature (Dust Cloud & Dust Layer)
  • Self-Heating
  • Burning Behavior (BZ)
  • Powder Chargeability
  • Volume Resistivity and Charge Relaxation Time

We will be happy to prepare a test plan that is based on your type of powder, operations, and process equipment.

What is the first step towards completing a Dust Hazard Analysis?

To verify if the powders/dusts handled are indeed combustible or if materials are only handled in closed containers in storage or warehousing activities (such “benign” processing is exempted from NFPA 652 application).

What is the second step in the process?

The next step towards compliance with NFPA 652 requirements is to complete the Dust Hazard Analysis (DHA) and identify areas of the process where materials could form ignitable dust suspensions or dust layers and access ignition sources. The DHA should answer the following key questions for all areas where powders and dusts are handled and processed:

  1. Can combustible particulate solids exist in a sufficient quantity that would allow flame propagation?
  2. Is there a mechanism to initiate dust suspension?
  3. Could the dust suspension concentration exceed the Minimum Explosible Concentration?
  4. Could effective ignition sources exist during 1-3 above?

What timeline is in effect for completing a DHA?

For existing processes, the owner or operator must schedule the DHA to be completed within three years of the issue date of NFPA 652, September 7, 2015. For new construction or modifications in excess of 25% of original cost, DHA shall be completed as part of the project.

What are some important aspects of dust hazard management?

We take into account building design, equipment design, housekeeping, ignition source(s) control, personal protective equipment, dust control, explosion prevention/protection/Isolation and fire protection.

What is an alternative to the prescriptive-based design for the control of combustible-particulate hazards?

Our qualified specialists can undertake a performance-based design which requires a consideration of practical methods and best industry practices that are provided to meet the life safety requirements, including combustible dust fire, deflagration, and explosion scenarios as well as the company’s mission continuity.