NFPA Journal

In 2015, NFPA formed a technical committee to create a new document for the fire service, one that would communicate an improved understanding of the science underlying the dynamics of structural firefighting. The committee included representation from small and large career fire departments, the volunteer fire service, instructor associations, research organizations, the insurance industry, and the International Association of Fire Fighters. Canadian, German, and Belgian interests complemented the US perspective on the committee.

The group faced a sizable task: to assemble a guide that offered direction to individuals and fire organizations on how to respond to burning buildings with approaches that were based on documented fire investigations, research, and fire dynamics testing, methods anchored in science that could achieve the most successful outcomes.

The timing of this challenge was crucial. The modern fireground had changed dramatically over the previous several decades; building design and materials, as well as the interior finishes and furnishings of those buildings, had all undergone significant changes and combined to create a greater fire risk that threatened both property and lives. The change in fire risk involving homes, for example, was startling: the combination of newer building materials, such as engineered lumber, and modern furnishings, which rely heavily on combustible materials including particleboard and foam, can create a fire risk much greater than older homes built with dimensional lumber and containing “legacy” furnishings made with hardwoods and cotton padding. Newer homes with modern furniture can burn much more aggressively than older homes, creating a greater risk for occupants and responding firefighters. Studies have shown that fires in newer homes can reach flashover in less than five minutes, compared to 20 minutes or more in older homes. 

This new type of fire called for new types of firefighting tactics, methods that were based in a scientific understanding of fire dynamics, the behavior of certain materials when exposed to fire, associated health hazards faced by firefighters, and many other areas that addressed hazards more comprehensively, and with a more fundamental understanding, than ever before. 

Six years later, that understanding provides the foundation for the new NFPA 1700, Guide for Structural Fire Fighting. Using NFPA 921, Guide for Fire and Explosion Investigations, as a model for how to translate an understanding of fire dynamics into applicable methods, NFPA 1700 addresses fire control within a structure by establishing a basic understanding of fire science and fire dynamics. Up-to-date information from recognized research efforts complements fundamental occupancy, building construction, and building system considerations. Chapters are dedicated to establishing strategies with tactical considerations to provide effective search, rescue, and fire suppression operations, as well as civilian and responder safety. The guide acknowledges threats to occupant lives while further addressing the protection of firefighters in an immediate environment that is dangerous to life and health by reinforcing the need for personal protective equipment and methodologies for contamination control.

NFPA 1700 is a keystone document that brings together the science, knowledge, and experience of firefighting. The information contained in the guide has been the basis for change in fire department standard operating guidelines across the US and around the world.


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Science & structures

As a guide, NFPA 1700 is a non-mandatory document, and it does not specify how fire departments must fight structural fires. Instead, it recognizes that a primary responsibility of the fire service is to save lives, and its purpose is to provide a framework for the development of policies, procedures, guidelines, and training resources for fire service organizations. Its 13 chapters and four annexes are designed to introduce science-based research into practical on-scene measures to benefit the safety of the public and the fire service, and to enhance property-conservation actions. The work by the technical committee demonstrates that the safety of firefighters and the public is indeed the top strategic priority. 

The guide’s educational material begins with a chapter on definitions. Many of the definitions have been collected from other NFPA firefighting standards and some definitions are new, such as the definition of an offensive strategy: “The plan for the actions and movements of arriving fire department units to control the fire, effect rescues, start searches for occupants, and extinguish the fire with the intent to commence operations inside the fire building.” Previously, the definitions regarding offensive and defensive strategies were based solely on where the firefighters would be operating—either inside or outside of the fire structure. In practice, though, using exterior fire control prior to or during interior operations is part of an offensive strategy. In short, the strategy outlined and defined in NFPA 1700 is based on the incident action plan, which is based on the size-up.  

The guide provides a concise summary of more than 30 studies that were conducted to examine firefighting environments, time to structural collapse, the capabilities of firefighting gear, and the effectiveness of firefighting tactics. Many of these experiments were conducted with the support of fire departments in New York City, Chicago, Phoenix, and elsewhere. In the studies conducted by NFPA and the UL Firefighter Safety Research Institute, technical panels with fire service representatives from a wide range of departments worked with the researchers to add their experience and keep the research true to the needs of firefighters in the field.

NFPA 1700 addresses fire dynamics and building construction in three chapters: Chapter 5 covers the fundamentals of fire science, Chapter 6 covers fire dynamics in structures, and Chapter 7 addresses building construction. The fundamentals chapter addresses combustion and fire dynamics basics to build a foundation for applying fire dynamics concepts on the fireground. Some of the fundamentals will be familiar, while others may be new. Consider the term “heat of combustion,” for example. Some fuels have a higher heat release rate than others, which can be based on the chemical energy stored in the fuel; the measurement of the amount of heat released per pound when the fuel is burned completely is the heat of combustion. Polyurethane foam, commonly used in the construction of padded furniture or carpet padding, has the potential to release twice the energy per pound of a pine board when it burns. The heat of combustion helps to explain why upholstered furniture made with synthetic materials spreads fire faster and burns with a higher heat release rate than furnishings made with wood, cotton, and wool. This is the kind of information covered in the guide that can help firefighters and fire departments make better, more informed decisions on the fireground. 

Chapter 6 takes the basics of how a fire burns and places the fire inside a compartment to illustrate the difference between a fuel-controlled fire and a ventilation-controlled fire. Flow paths are used to explain how fire and smoke will move through a building. Small differences in pressure can create fire gas flows with velocities between five and 20 miles per hour. Special cases of ventilation flow and the potential hazards they can present are highlighted. These special cases include wind-influenced fires, attic fires, basement fires, and exterior fires. This information is intended to provide a connection between fire conditions inside the structure and what is observed during size-up.   

Chapter 7 provides structural performance information to aid firefighting personnel in properly assessing the impact of the fire on the building materials and building construction. Building systems are defined and listed if they are commonly included in certain buildings based on the type of construction.  

Strategy & safety     

Three chapters address the application of tactics and strategies. Chapter 9 addresses strategic considerations and supports the conduct of initial assessments to determine a strategy, as well as ongoing assessments to evaluate the effectiveness of operations. Information is provided on what to consider in your initial arrival factors and 360-degree surveys and how these factors may affect your strategic decisions. Chapter 10 presents the tactical considerations for coordinated fire control and extinguishment. Tactics are divided into the categories of water (suppression) and air (ventilation). For each tactic, information is provided on the objective of using the tactic, how it works, the preferred technique, an alternate technique, and safety considerations. Chapter 12 addresses science-based approaches to dealing with specific structural challenges, including below-grade fires, photovoltaic hazards, vacant buildings, hospitals, and various forms of residential occupancies. It is expected that this chapter will grow considerably in the future, since a number of research projects were underway while the guide was being developed.

Additionally, two chapters directly address firefighter safety and health. Chapter 8 provides, among other things, a summary of the thermal design limits of firefighter personal protective equipment (PPE) based on nine different NFPA standards. Understanding the protective capabilities of PPE and the limitations of other types of firefighting equipment in various thermal conditions generated by a fire can help an officer or incident commander decide on an incident action plan that will enable the fire crews to be successful and safe. Similarly, Chapter 11 addresses a variety of ways to minimize the cancer exposure and health risks on the fireground. Using a science-based approach, the chapter outlines the importance of wearing respiratory protection and full PPE, and why on-scene decontamination after the fire is essential—a step that has been shown to remove more than 80 percent of the combustion products from the surface of the gear.  

NFPA 1700 is a resource for change agents in any fire organization, regardless of size and staffing profile, to bring an up-to-date understanding of fire dynamics to structural firefighting procedures and training curricula. As research into fire dynamics and other areas continues, so will the evolution of NFPA 1700. Considering the diversity of the firefighting spectrum—prevailing occupancy and building types, water supplies, staffing, PPE, available firefighting equipment, and more—it is essential that the scientific foundation provided by NFPA 1700 continues to grow. Together, we can advance the art of firefighting through science by informing what has become accepted practice with knowledge gained through accepted research.

—An expanded version of this article will appear in the Fall 2021 issue of NFPA Journal. Joseph M. Jardin, an assistant chief with the Fire Department of New York, and Daniel Madrzykowski, research engineer at the Firefighter Safety Research Institute at UL, are members of the NFPA 1700 Technical Committee on Fundamentals of Fire Control Within a Structure Utilizing Fire Dynamics. Top photograph: Getty Images