The National Institute of Standards and Technology's Impact on Fire Safety Standards

Short abstract

The authors document the role of the National Institute for Standards and Technology (NIST) in the initial adoption of smoke alarms, ongoing changes to smoke alarm performance requirements, and ongoing research on wildfire safety in the wildland urban interface. They also provide econometric estimates of the social and economic impact of the fire safety standards that NIST helped develop.

Abstract

The authors document the role of the National Institute for Standards and Technology (NIST) in the initial adoption of smoke alarms, ongoing changes to smoke alarm performance requirements, and ongoing research on wildfire safety in the wildland urban interface. They also provide econometric estimates of the social and economic impact of the fire safety standards that NIST helped develop.

Standards play an important role in health and safety of everyday life, affecting everything from food production and transportation services to building design and consumer products of all types. Standards help ensure that goods and services traded in national and global marketplaces are both safe and effective. Without effectively implemented standards, the world would be a much more hazardous place to live in. The National Institute of Standards and Technology (NIST) is the U.S. government's primary agency for shaping and influencing the development of measurement standards, both nationally and internationally, and plays a unique and critical role in the development of measurement standards.

While the safety and health benefits of standards are generally acknowledged, our understanding of their value, how they accrue, and what entities and activities are responsible for creating them is limited. In October of 2018, NIST asked RAND to estimate the benefit of NIST's research contributing to particular fire safety standards. The original objectives of the project were to (1) document the role of the NIST in the standards development process, (2) estimate the value these standards provide to society, and (3) thereby inform the economic value of NIST's contribution to these standards. This study presents results for the first two objectives. Given that NIST's contribution is one of several inputs combining to create these standards, NIST's share of the credit for their value could not be quantified.

Our analysis focused on case studies in standards for home smoke alarms and for protecting structures at the wildland-urban interface (WUI), the transition areas between wildlands and urban spaces. We demonstrate NIST's role in standard development through three case studies, selected in coordination with staff of NIST's Fire Research Division: historical work that led to the initial adoption of smoke alarms, ongoing changes to smoke alarm performance requirements, and ongoing research on wildfire safety in WUI. We then conduct novel analyses to indirectly estimate the potential impacts of smoke alarm and WUI standards.

Our analysis compiles many different sources of information, including reviews of research literature, interviews with representatives of NIST laboratories and standards development organizations (SDOs), review of SDO documentation of the standards development process for several standards and codes, observation of an SDO meeting, a survey of research staff in the NIST Fire Research Division, a novel module on smoke alarm usage in a national representative survey, analysis of the relationship between state building codes and fire safety outcomes, and analysis of data from the 2018 Camp Fire in Paradise, California.

Our study shows that NIST's role in standards development comes at the very beginning of the process, providing the foundational research on which subsequent activities are built. NIST researchers and staff proactively and intentionally engage with a variety of SDOs, and these SDOs in turn deeply value NIST's participation. This study highlights multiple examples where research conducted by NIST proved to be essential to developing effective standards.

Smoke Alarm Standards

NIST research played a critical role from the late 1960s through the late 1970s in rapidly shifting home smoke alarms from novelty to standard practice. Data from several early demonstration projects in which NIST participated showed benefits from installation of smoke alarms. In addition to promoting the inclusion of smoke alarms in homes, NIST's work also helped advance the effectiveness of smoke alarm technology, which led to a number of design improvements and specifications and ultimately to the first smoke alarm standard in 1974.

Since the mid-1970s, the use of smoke alarms in homes has grown substantially, largely facilitated by the adoption of state and local ordinances requiring their use. Following this early period, NIST continued to support the development of smoke alarm standards with work targeted at specific aspects of smoke alarm placement and performance. One area of research focused on revisiting smoke alarm design and testing in light of the shift to the use of largely synthetic materials in upholstered furniture versus natural furnishing materials for which early smoke alarm designs had been developed. A major outcome of this research included updates to test performance requirements reflecting conditions created in fires of modern synthetic furnishing materials.

Another aspect of this later research focused on reducing nuisance alarms, primarily stemming from cooking aerosols and bathroom shower mist. Nuisance alarms were an important area of investigation because the inconvenience often led home occupants to disable smoke alarms, thereby leaving occupants unprotected and contributing to deaths associated with residential fires. Since the late 1980s, residential smoke alarm standards have evolved as a result of NIST's contributions and reflect changes in restrictions on smoke alarm placement and technology. Most recently, NIST research endeavored to resolve nuisance alarms independent of location or technology, which has motivated a 2020 revision to smoke alarm standards to adopt this newest capability.

Prior to examining the benefit of smoke alarm standards, we compiled and summarized research on the effectiveness of smoke alarm technology. This body of research shows that the presence of a working smoke alarm in a home reduces the number of fires per home, the number of reported fires per fire, and the number of fatalities per reported fire, combining to result in the risk of a fire fatality in a home with a smoke alarm being 7 to 26 times lower than in a home without a smoke alarm.

To measure the social and economic impact of smoke alarm standards, we developed a novel database documenting state-level variation in the adoption of smoke alarm standards in residential housing codes. We found that the frequency with which states update residential building codes can vary significantly, although we did not find evidence that adopting codes containing the most recent smoke alarm standards significantly alters the number or severity of fires nor the number of injuries or fatalities. We suspect this is because the largest gains in fire safety from smoke alarms occurred prior to 2003, which is the earliest point in time we can measure these correlations. In fact, by 2003, 95 percent of households had already installed at least one smoke alarm. As a result, safety impacts imparted through the adoption of updated residential smoke alarm standards since 2003 have been too small to measure.

These results do not necessarily mean that further updates to smoke alarm standards or building codes are irrelevant. Ongoing work on smoke alarm standards, supported by NIST research, continues to address nuisance alarms, as well as testing requirements, system interconnection, notifications targeting children, and other topics. A nationally representative survey of American households conducted by RAND in March 2020 found that 36 percent of households reported having disabled a smoke alarm (e.g., by removing the batteries) to prevent nuisance alarms, which is an issue that current standards development efforts are seeking to address. To the extent that new standards, based in part on NIST research, can reduce the frequency with which households disable smoke alarms, that would provide meaningful improvements in fire safety and general well-being.

Wildland-Urban Interface Standards

As the risk of WUI fires has increased, the research community has begun paying increased attention to wildland fires, which have grown in number and intensity and are causing more damage and taking more lives. The increase in WUI risks is driven by increased human-caused ignition and increased building exposure. The large wildland fires that occurred in the 1990s and early 2000s appear to have motivated NIST's work in this area (e.g., see Manzello, Cleary, and Yang, 2004), which began as an extension of its general fire efforts at the National Fire Research Laboratory.

According to NIST personnel, early WUI fire research conducted by NIST focused on developing a better understanding of how fire spreads from the vegetative fuels of the wildland to structures. By 2004, this research had evolved to an examination of firebrands—small flaming or glowing embers that may be transported by the wind into a building's vents or crevices and cause structure ignition. NIST's research demonstrated that a majority of structure ignitions were in fact caused by firebrands rather than flame contact or thermal radiation and continuing research is examining gaps in knowledge about firebrands. NIST has also collected data on historic fires to further study of fire behavior and consequences. Other complementary research has examined the socio-technical aspects of WUI risk.

NIST's work is providing fundamental groundwork needed to develop evidence-based WUI standards and influence study of different building designs and materials to deter firebrand-driven ignition. NIST also provided technical support and leadership in the development and implementation of Executive Order (EO) 13,728, Wildland-Urban Interface Federal Risk Mitigation (Obama, 2016).

Research into the effectiveness of design changes is still in its early stages, so the effects of potential design changes on survivability are highly uncertain. To measure the social and economic impact of WUI standards, we conducted a geospatial analysis of the extent to which homes built with newer construction methods avoided damage or destruction during the 2018 Camp Fire in Paradise, California. Our results suggest that the survivability of houses has generally been improving over time. This result is consistent with steady improvements in standards and the associated changes in building practices, although other explanations are also possible.

We used two different approaches to estimate the savings that might occur if all houses within the 2018 Camp Fire perimeter were as survivable as houses built in 2000 to 2009 (the decade in which houses built had the lowest damage rates). Results of the two approaches indicated a 6- and 43-percent reduction in housing losses, respectively, which we estimated to be equivalent to $600 million or $4 billion in averted losses.

Although we did find a general relationship between evolving standards and reduced damage in residential homes, limitations in data meant we were unable to link these improvements to a specific change in building codes. Studies of buildings affected by wildfires typically collect minimal information on undamaged buildings, making it impossible to compare the design of buildings that ignited with those that survived. Collection of such data could greatly improve our understanding of the factors that increase survivability in wildfires, which would lead to the development of improved WUI standards and building codes.

Conclusion

The development and adoption of standards and codes involve a number of different stakeholder groups, sometimes with competing interests. Standard development requires basic research, development of standardized testing methods, and the coordination and integration of stakeholder needs. Adoption further requires widespread incorporation of standards into codes and enforcement of those codes. Because of the collaborative and multistage nature of this process, the economic and social impacts of both the standards themselves and the specific contributions of particular entities toward the development of those standards are difficult to isolate. In addition, in the case of standards that apply to infrastructure, such as those for fire safety, it can take years to decades for the benefits of research to make their way into the built environment and be realized.

Our analysis identified a number of important contributions from NIST to the development and adoption of standards for smoke alarms and WUI protection. While our quantitative analyses were not able to detect significant economic benefits that can be linked directly to specific standards, this in no way suggests that fire safety standards, and NIST's contributions to them, do not have great value. In the case of smoke alarms, the most significant gains were likely made prior to the time period for which we conducted our analysis. Conversely, in the WUI setting, standards are still in the active research stages, and the biggest benefits are likely yet to be realized. In both cases, we discuss clear evidence of steady safety improvements over time and suggest that those steady improvements may be largely or partly attributed to the concurrent evolution of multiple related standards. Standards may also have indirect economic benefits, such as increasing technology development and adoption and efficiency of markets, which our analyses also cannot capture.

The type of foundational research conducted by NIST is a necessary precursor to the development of standards that yield meaningful public health and safety benefits. Further, although other entities devoted to fire safety research exist, substitutes to NIST are not readily apparent. Thus, while we cannot know if another entity would have made the contributions to smoke alarm and wildfire safety standards that NIST did, it is clear that NIST's leadership role in basic research and standards development has been critical for bringing the standards and their adoption to their current status.