Fire Risk Reduction in Buildings Program

The total cost of fire in the United States in 2008, as defined by NFPA, is estimated at $362 B, or roughly 2.5% of U.S. gross domestic product. Structure fires and fire protection account for $170 B. To reduce the overall U.S. fire burden, the Fire Risk Reduction in Buildings program focuses on the development and application of measurement science and standards directly on the two largest components of the structure fire problem: a reduction in the cost of installed fire protection through performance-based design ($62 B) and a reduction in residential fire losses ($31 B), which includes deaths, injuries, and property loss, through prevention and mitigation research. 

Objective:To develop and deploy advances in measurement science to increase the safety of building occupants and the performance of structures and their contents by enabling innovative, cost-effective fire protection technologies by 2016.

What is the problem?   The total cost of fire in the United States in 2008, as defined by NFPA, is estimated at $362 B, or roughly 2.5% of U.S. gross domestic product.^[1] Of the total cost, structure fires and fire protection account for nearly $170 B^[2]. Fire protection costs ($62 B) are the single largest component of the structure fire problem and are typically estimated from 2% of construction costs overall in the developed countries up to 12% of construction costs for non-residential buildings in the U.S.^[3] The second largest component of the structure fire problem, at $35 B, is direct fire losses (property loss and civilian injuries and deaths). Structure fire losses are dominated by residential fires, totaling $30.7 B in 2009 (85% of all fire deaths, 77% of all fire injuries, and 72% of all structure fire property loss).^[4]  This program is focused on reducing the burden of the two largest components (fire protection cost and residential fire losses).

Why is it hard to solve?  The degree of complexity of interacting fire processes involving complex chemistry, radiative and convective heat transfer, combustion mode, fluid dynamics, structural dynamics, and human behavior preclude the use of existing approaches and tests that address only one of these disciplines. The lack of knowledge about interacting fire processes inhibit accurate simulation of fire spread, growth, detection, suppression and egress in a typical building fire. ^[5] The Program is composed of 8 projects and unique measurement science challenges exist in each of the projects. For fire modeling, state of the art sub-models are needed to describe complex fire-related phenomena such as turbulent flow, combustion, radiative heat transfer for length and time-scales that vary many orders of magnitude. For fire protection in buildings, methodologies are needed to account for uncertainties in the estimate of safety margins for fire performance and to demonstrate that proposed innovations are technically feasible, safe, and economically viable. Challenges in fire measurements are difficult to implement due to extremely harsh thermal environment, transient chemical species, soot-laden flows, measurement interference, scaling issues, and turbulent flow fields. 

Furthermore, developing the measurement science tools to enable industry to accurately evaluate the sustainability of fire safe products, especially those based on nano-materials, is primarily impeded by the lack of data available on their sustainability, i.e., the data are not available on their environmental health and safety, manufacturability, ageing and recyclability. The challenge of coupling the difficult fire problem to the equally complex sustainability analysis is considerable.

How is it solved today, and by whom?  Many parts of the national fire problem remain unresolved and innovation is limited due to gaps in measurement science. For fire safety design in constructed facilities, many fire protection professionals and building designers still follow the traditional prescriptive-based approach. While fire safety innovations will continue to reduce fire losses, a performance-based approach will provide flexibility for cost-effective fire safety design to achieve an acceptable level of fire protection. This will enable U.S. building and fire protection industries to compete effectively in the global marketplace as more and more countries are transitioning from prescriptive-based fire safety to a performance-based approach.

Fire research is conducted in commercial laboratories (FM Global, Southwest Research Institute), US government laboratories (Sandia, NRL, FAA), and around the world (NRC-Canada, BRE, BRI, SP, SKLFS). However, most groups focus on some subset of the issues, e.g., the flammability performance, passing new regulations, material cost, halogen/environmental, or nanotechnology aspects only. In Europe, the PREDFIRE NNANO program focuses on non-halogenated nanoclay flame retardants, but not on the development of better bench scale flammability tests or sustainability.^[6] This program is only open to European industry and therefore puts US industry at a competitive disadvantage, especially with respect to dealing with European regulations mandating steps towards sustainability (e.g. REACH, RoHS, WEEE).^[7] A concerted program on developing sustainable flame retardants has been called for by VECAP participants.^[8]

Why NIST?    This program directly fits in EL’s mission^[9] and vision^[10] and is consistent with the National Institute of Standards and Technology Act, which directs NIST to conduct basic and applied fire research into the behavior of fires in buildings and design concepts for providing increased fire safety.^[11] This work is directly aligned with EL’s strategic priority goal on Measurement Science for Disaster-Resilient Buildings, Infrastructure, and Communities and leverages EL’s core competency on Fire protection and fire dynamics within buildings and communities. NIST is uniquely qualified to lead this effort, having the technical expertise, infrastructure, and experimental facilities to address key topics in fire protection measurement science. Individual companies do not have the resources to develop the facilities and expertise needed to be successful. The responsibility for ensuring that these tools are accurate will, by necessity, fall largely on governmental fire research organizations. 

What is the new technical idea?  There are two primary thrusts in the FRRB program: reduce the cost of fire protection in buildings by enabling performance-based design (PBD) and reduce residential fire losses through reduced flammability of key building contents. Within the PBD thrust, there are several new ideas. First, use of predictive fire models for performance-based design depends on demonstrated accuracy and robustness of the models combined with  targeted development based on user needs. Recent progress in verification and validation (V&V) standards has enabled V&V for both FDS and CFAST to be conducted in a consistent manner. Additionally, new algorithms will improve the accuracy of the predictions.^[12] The toxicity project will develop small-scale measurements capable of predicting material toxicity at full-scale, which is the critical bridge between the fire and the ability of occupants to escape a building. The egress project will capture novel movement and human behavior data to establish the likely distribution of life safety outcomes for structure fires. The ability to predict fire growth and spread, the combustion products and their effect on occupants, and the movement / behavior of the occupants is critical to realizing the potential of PBD. Finally, new measurement capabilities for predicting the response of multi-story structural frames to fire and other imposed loads will be developed in the NFRL, which will enable more cost-effective structural installations. 

The strategy to reduce residential fire losses through improved material flammability is pursuing several new technical ideas. First, the foam project will evaluate novel nanoparticle fire retardant-filled Layer-by-Layer (nanoFR/LbL) coatings as a technology to reduce the fire hazard of polyurethane foam in order to reduce the heat release rate (HRR) of foam by 30%. Closely aligned, the furniture flammability project will develop a technically sound furniture design tool based on characterized physical and combustion properties of the furniture components that will be used by furniture manufacturers to produce residential upholstered furniture (RUF) with improved flammability behavior.^[13] The design tool would enable RUF manufacturers to identify the materials and configurations necessary to produce RUF with desired levels of fire performance. The smoke alarm project will characterize very early combustion signatures. These signatures will be differentiated from nuisance sources and novel real-time analytical methods will achieve a reduction in sensing time and a reduction in nuisance alarms. Finally, the fire retardant project will assess, with significant input from industry, the fundamental principles and modes of action of gas-phase fire retardants, as well as the appropriate standard test methods to quantify gas-phase FR effectiveness.  

Why can we succeed now?  NIST is uniquely positioned to reduce the burden of structure fires in the United States. The Program is focused on improving standards and codes, and is staffed with world-class experts capable of producing significant advances in measurement science to reduce the risk of fire hazard in buildings. Recent technological advances such as highly accurate analytical instruments, and fine and sub-grid modeling of fire physics and chemistry have provided opportunities to improve and advance current fire metrology and fire models. Stakeholders and customers are demanding tools and knowledge that will enable performance-based design (e.g., fire modeling, data and knowledge on evacuation), economic-based decision making, and fire safety engineering, facilitating the rapid transfer of research results into practice.

EL has extensive expertise in real-scale flammability, validated bench scale flammability measurements, life cycle assessment (LCA), nanotechnology, materials decomposition modeling and novel flame retardant approaches; the combination of these expertise will produce the necessary tools for industry to develop sustainable fire safe products, innovate and compete in the markets where new domestic and foreign regulations mandate both performance and sustainability.^[14]

What is the research plan?   There are two primary thrusts in the FRRB program: to reduce the cost of fire protection in buildings by enabling performance-based design (PBD) and to reduce residential fire losses through early and reliable warning and reduced flammability of key building contents. Within the PBD thrust, the research plan is to enable the next generation of PBD through accurate simulation of the hazard of a fire to building occupants and the performance of the structure. This will require four highly coupled projects. First, predictive fire modeling will simulate the growth and spread of fire. Critical tasks include extending the FDS V&V parameter space, implementing novel algorithms, enabling direct CAD import for building geometry, and improving the computational efficiency of SmokeView.^[15]  Second, the movement and behavior of the occupants must be characterized. The egress project will publish a database of stairwell movement characteristics for tall buildings and simulate occupant behaviors during a fire, utilizing a novel theoretical framework. Third, the generation and transport of toxic combustion products will be measured. The toxicity project will produce a draft standard capable of capturing full-scale product toxicity from bench-scale measurements. Finally, after fully commissioning the NFRL, the performance of a multi-story structural frame responding to fire and other loads will be characterized. Each project is critical to realizing the full potential of the PBD thrust area.

The research plan for the residential fire loss thrust will primarily address a reduction in the flammability (ignition and HRR) of residential soft furnishings and enable early warning of unwanted fires. To mitigate the largest fuel source in homes (residential upholstered furniture, RUF), three highly coupled projects will create a design tool and develop the measurement science for condensed/gas phase technologies for furniture construction. This will enable flexible and cost-effective design alternatives for manufacturers, while significantly reducing the hazard of RUF. First, the foam project will identify the micro- and macrostructure architecture of the nanoFRs and the LbL coatings that can be used to control foam flammability, developing and evaluating candidate tools to measure released nanoFR and separate tools to stress foam under conditions simulating end-use conditions. The furniture flammability project will conduct small- and meso-scale measurements of RUF to establish the technical basis for a RUF design tool which will produce RUF with substantially reduced fire hazard. Third, the advanced fire retardant project will establish the fundamental principles and modes of action of gas-phase fire retardants, as well as the appropriate standard test methods to quantify gas-phase FR effectiveness. In addition, the smoke alarm project will characterize very early combustion signatures using a novel multi-angle multi-wavelength light scattering measurement device. These signatures will be differentiated from nuisance sources, and novel real-time signal processing will achieve a reduction in sensing time and a reduction in nuisance alarms. Together, these four projects will produce the measurement science to enable a significant reduction in residential fire losses.

How will teamwork be ensured?  This program is part of the Measurement Science and Standards for Disaster- Resilient Buildings, Infrastructure, and Communities Goal and is coordinated with the other programs (including Fire Risk Reduction in Communities Program and the Structural Performance under Multi-Hazards Program and is derived from strategies outlined in the draft Innovative Fire Protection Roadmap.^[16] There is great synergy across programs and their contributions are required to achieve the strategic goal. The Program involves staff from all units in the Fire Research Division as well as staff in the EL Applied Economics Office and the Materials and Construction Research Division. Interaction among team members is ensured by informal and formal sharing of project information in individual meetings and group gatherings such as Fire Research seminars.

What is the impact if successful?  Measurement science in the PBD thrust (collectively) will enable more efficient fire safety design of buildings, which may exceed $5B annually.^[17]   It is anticipated that more than 20 individual codes, standards, and regulations will be created or improved by this thrust.^[18] Each project emphasizes outputs, outcomes, impacts aligned with the thrust objective. Predictive fire modeling will continue to support a user group of roughly 10,000 professionals, establish and implement consensus V&V methods, and enable performance assessment of complex buildings. The toxicity project will produce a draft consensus standard through ISO capable of estimating product toxicity using bench-scale tests. The egress project will develop a draft V&V consensus standard (ASTM), enable rapid evacuation of high-rise buildings through implementation of occupant-use elevators, and establish a technical foundation for stair movement through a comprehensive database of occupant movement. In addition to world-class large-scale HRR measurements, the NFRL will change the practice of performance based design for structural and fire engineering by enabling multi-load analysis of building systems to include fire. 

Measurement science in the residential fire loss thrust will enable a major reduction in residential fire losses. First, estimates suggest that early and accurate fire sensing can achieve a 50% reduction in residential fire deaths and injuries.^[19] Further reductions will be enabled through sharp reductions in the flammability of foam and the hazard of upholstered furniture (a major component of residential fire load).

What is the standards strategy? The program has a significant focus on delivering technical findings to improve codes, standards, and practices associated with reducing the risk of fire in buildings. Recent NIST technical contributions include the 2006 and 2009 International Building Code and the 2009 NFPA Life Safety Code (improvements to egress markings, high-rise evacuation, and stairwell integrity are adopted in all 50 states), ISO (toxicity measurement and calculation methods and cigarette testing protocols are now the worldwide standard of practice in toxicity calculations and reduced-ignition cigarette testing), and UL 0217 standard on nuisance-resistant smoke alarms (the majority of residential smoke alarms are certified using the UL 0217-2011 standard). The CFAST and FDS models have transformed performance based design of fire protection in buildings and have been used to support codes and standards development worldwide.^[20] Changes to fire safety engineering practices include the Society of Fire Protection Engineers (SFPE) “Engineering Guide to Substantiating a Fire Model for a Given Application” and the US Nuclear Regulatory Commission (NRC) publication “Fire Model Verification and Validation Study (NUREG-1824, 2007),” which stipulates how fire models are to be used in nuclear power plant applications. The standards strategy for the FRRB program focuses on two technical thrust areas: reduction of residential fire losses and enabling performance-based design (PBD). Standards development needs for reducing residential fire losses include: a) standard to assess toxic effects of combustion products on people (FY12), b) improved test method for evaluating reduced-ignition cigarettes (FY 13), c) standard for reduced flammability of upholstered furniture (FY16), and d) standard for enabling early detection and reliability of smoke alarms (FY15). Standards development needs for enabling performance-based design include: a) standards for verification and validation of computation fire and egress models (FY13), b) standards to improve building evacuation (FY14), and c) standards to improve structural design under fire conditions (FY 16).

Researchers in the FRRB program implement a full range of activities for influencing codes and standards which are tailored to the alignment with programmatic objectives, available resources, and staff expertise. At the highest level of involvement, the staff convene and lead committees. Current FRRB examples include ISO (chair, secretary, and task leaders), ASME (task group leadership), and UL (task group leadership). Additionally, researchers are full voting members on key committees (3 NFPA committees, ICC Means of Egress, 5 ASTM committees, 1 ASCE^[21] committee, and 15 ISO committees and working groups). Finally, researchers often make invited technical presentations to committees or hearings in order to communicate results of NIST research. 

Additionally, the Program will work with regulatory agencies on critical research, including collaborations with the NRC on fire modeling^[22] and with the CPSC on mattress flammability, cigarette ignition, and smoke alarm/sprinkler effectiveness. Fully aligned sponsored research from regulatory agencies will accelerate the time frame typical for realization of impact.

How will knowledge transfer be achieved?  Knowledge and results from the program will be disseminated to customers and stakeholders through archival publications, reports and data on the web, reports to sponsors, presentations at technical conferences, downloadable software, the participation in workshops, standards, codes, and technical committee meetings, scientific engagement through the NIST post-doctoral and guest researcher programs, and strategic planning/roadmapping involving a broad range of stakeholders.

Major Accomplishments:

 Outcomes:   The FRRB program has significantly advanced measurement science which will enable a significant reduction in residential fire losses. First, the nanoparticle foam project has developed several new measurement capabilities, including the ability to use carbon nanotubes and nanofibers can be used in the LbL process,^[23] a foam smoldering assessment device and protocol that quantifies smoldering performance,^[24] and developed a UV-VIS spectroscopy method to quantify carbon nanotubes at concentrations an order of magnitude lower than any previously reported method.^[25] The pyrolysis project developed and validated a new measurement method to capture the broad-band IR absorption of polymers subjected to radiant heating, so that this parameter can be accurately used in pyrolysis modeling. Additionally, the project published a database of broadband IR absorptance and reflectance measurements of typical commodity polymers which is now actively used by researchers in numerical pyrolysis model development. The advanced detection project recently led the development of an improved nuisance source standard for smoke alarms (UL 0217).

The FRRB Program is advancing the underlying basis of performance-based engineering. The fire modeling project continues to support the practice of fire protection engineering and roughly 10,000 registered users through the publication of validated, numerically efficient fire models (FDS, CFAST, and SmokeView). Recent outcomes include ASTM and ISO V&V standard development^[26] and engineering design guides.^[27] The egress project has published complete datasets for five building evacuations on NIST website with hundreds of registered users in October 2010.^[28] Video-based observations of 12 unique fire drill evacuations have been completed with analysis published for six. The toxicity project continues to develop the technical basis for measurement and prediction of toxic hazard of combustion products through creation and modification of ISO standards documents.

 Recognition of EL:   The program staff have a leadership role in developing measurement science for innovative fire protection, which is internationally recognized. For example, FDS/Smokeview and CFAST are considered premier fire models worldwide. ^[29], ^[30], ^[31], ^[32], ^[33] Recognition of EL can be documented through honors bestowed on staff for their program-related research activities, ^[34], ^[35], ^[36]  participation on editorial boards,^[37], ^[38] research steering committees,^[39] as keynote speakers,^[40] leadership in the organization of international conferences,^[41],^[42],^[43],^[44] and leadership positions in international fire safety organizations.^[45] EL research on flammability was recognized as one of the top five NIST National Nanotechnology Initiative (NNI) accomplishments for the President’s Council of Advisors on Science and Technology (PCAST) presentation of their review of the NNI to the President in March. National Nanotechnology Coordination Office (NNCO) is developing a video of the programs results. The U.S. House of Representatives Committee on Energy and Commerce requested the assistance of the EL staff in gathering information on flame retardants important to the reauthorization of the regulatory authority for the EPA known as the Toxic Substance Control Act TSCA and continue to serve on EPA committees.^[46]