Residential fire losses substantially dominate the total fire losses in the U.S. accounting for 83% of the 2855 deaths, 78% or the 16500 injuries, and 58% of the estimated $ 12.5 billion in property loss (Karter, M.J., Fire Losses in the United States in 2012, National Fire Protection Association, Quincy, MA, September 2013). This project focuses on reducing these losses through 1) innovation in new fire safety products, 2) better use of existing fire safety products, 3) knowledge to enable development of more effective codes and standards, and 4) promoting public awareness of improved safety information.
To enable a reduction in residential fire deaths and injuries by conducting targeted research on advanced household fire alarms and cooking fire hazard reduction, and developing a system for evaluating the impact of new fire protection technology on residential life safety.
What is the new technical idea?
The new technical idea is to approach residential fire safety through interrelated research to bring innovative products to market, enable more effective codes and standards changes and promote public awareness of new residential fire safety information simultaneously. Most fire deaths and injuries occur in household fires. Residential fire safety features and their operational state vary from household to household and depend on a building’s age, local building codes, level of enforcement, and the knowledge and commitment of occupants (landlord/renter, owner occupant). Developing and evaluating technologies to reduce residential fire losses typically requires new measurement science capabilities to enable advanced technologies. Codes and standards can be very slow to change, and even slower to adopt. In the meantime, organization are requiring increasingly more research and data to justify changes to technical codes and standards Historically, NIST research has impacted furniture flammability, RIP cigarettes, residential sprinklers, and smoke alarm codes and standards. Public awareness is crucial to implementing and maintaining fire safety features. Household fire safety messaging campaigns need bona fide information derived from un-biased research to provide accurate and relevant advice. This project will reduce residential fire loss by developing the technologies for more sensitive/earlier detecting smoke and fire alarms, evaluating technologies to reduce the occurrence of kitchen fires (leading cause of household fires), and developing a system for evaluating the impact of new fire protection technology on residential life safety which can be used to guide household fire codes.
Early detection of ignition sources (e.g., electrical and cooking) via sensing of early degradation products could significantly impact the fire losses and deaths attributed to these ignition sources. Flame detection may provide a “fool proof” way to discriminate cooking activities from real fire hazards at the earliest possible moment for unattended cooking. Beyond advances in sensing technologies, a key relationship that needs to be understood is the interaction of humans to information presented by residential fire detection systems (e.g. obvious nuisance alarm – ignore or disable, failure to awaken a sleeping individual, tolerance of a “learning” phase of an advanced alarm, etc.) For instance, an intelligent fire alarm system that knows when cooking appliances are turned on, what time it is, and where occupants are located and where located in the immediate past may be used to inform occupants much differently than a fire alarm system that does not have this information. Special attention to elder residents may be critical in this research as the population in the U.S. is increasingly aging and their ability to be aware of and respond to an alarm is significantly different. This research could lay the foundation for including the response of the elderly in the fire codes.
What is the research plan?
This project is separated into three interrelated research subtopics whose outputs will be used to demonstrate advanced household fire alarm concepts and cooking hazard reduction strategies, and to develop a method to quantify the relative improvements in household fire safety that different technologies can make.
Subtopic 1 will continue to develop the measurement science to discriminate smoke and nuisance aerosols and test advanced detection algorithms. We continue to develop an extensive data set of smoke and nuisance source characteristics including particle size distributions and concentrations, and light scattering properties using the smoke nephelometer, aerosol polarimeter (SNAP), along with carbon monoxide and carbon dioxide gas concentrations. Experiments will be conducted in the fire emulator / detector evaluator (FE/DE), the fire alarm test room or a full-scale room in the NFRL. We have expanded the gas species measurements to include HCN and are publishing the existing data for advanced alarm development including nuisance sources in the fire alarm test room, and full-scale data from the new fire tests specified in ANSI/UL 217-2015. We will continue to support the development of standard nuisance source test methods by building and testing new equipment and nuisance source surrogates to replace current full-scale cooking nuisance source test with an equivalent small scale test.
Subtopic 2 is developing and demonstrating techniques to reduce cooking fire hazards, and supporting standards development for cooking fire safety technologies. The results and conclusions of the exploratory research on using smoke measurements to alert to pre-ignition cooking conditions have been documented in a manuscript. The fire detection room was modified to conduct cooking fire experiments to assess the ability of intervention/suppression technology. We are assessing the effectiveness of sensing and automatic power cutoff to a variety of stovetop and pan construction configurations . We are actively participating in standards development for cooktop fire safety. Experiments will be conducted using promising current technologies, and promising sensing technologies from the advanced household fire alarm task to demonstrate potential risk reduction strategies for kitchen fires.
Subtopic 3 is focused on aspects of occupant response and egress behaviors in residential settings and developing a conceptual system for evaluating the impact of new fire protection technology on residential life safety. Previously this subtopic concluded the research outputs of the Safety of Building Occupants project.
We have surveyed available data on residential occupant response and egress behavior to identify research gaps, and assess the need for additional data including issues that are known to affect occupant fire response and egress behavior of older residents and a manuscript was prepared documenting the literature survey, research gaps and data needs.
A methodology is being developed to assess the impacts of a product change (harder to ignite, slower fire spread, lower HRR, less toxic byproducts, better detection, better suppression, etc.) given various levels of household fire safety infrastructure (i.e., number, location and type of smoke alarms, CO alarms, sprinklers, etc.) and occupant characteristics. It will include statistical distributions with estimated uncertainties for various aspects of a community including: housing stock (number of rooms, total area and layouts, smoke alarm coverage and sprinklered spaces), various response and egress actions for different segments of the population (for instance, the alarm waking effectiveness has been shown to be a function of age, as has egress speed) and fire scenarios. It is envisioned the multiple runs (on the order of 106) of the computer fire model CFAST using input files drawn from sampling of the various distributions would form the basis of a probabilistic methodology for estimating building fire hazard. Developing performance measures that represent the results accurately, are easily interpreted, and allow the user to set performance standards is critical.