Richard Gann

National Institute of Standards and Technology | NIST · Fire Research Division

A standard procedure is needed for obtainingaccurate values of the yields of fire effluent components that are associated with harm to people from a singleacute exposure to the effluent from a fire involving realistic commercial products. We compare yields of toxic gases generated by four bench‐scale apparatus to the yields from previously conducte...

This paper summarizes the primary structural systems that comprised World Trade Center (WTC) 1, 2, and 7, which were destroyed in the terrorist attacks of September 11, 2001. There were four major structural subsystems in the towers: the exterior walls, the core, the floor system, and the hat truss. The major structural systems within WTC 7 were th...

The National Institute of Standards and Technology (NIST) conducted an extensive investigation of the collapse of the three tall World Trade Center (WTC) buildings. A central part of this investigation was the reconstruction and understanding of the initiation and spread of the fires. This paper describes the reconstruction of the fires, the therma...

Current existing and proposed US flammability standards for soft furnishings such as mattresses and upholstered furniture specify a “standard” cigarette as the ignition source in smoldering resistance performance tests. With the increasing prevalence of reduced ignition propensity cigarettes in the marketplace, the conventional cigarette that has b...

The Department of Defense's Next Generation Fire Suppression Technology Program (NGP) has completed its sixth year of research with a goal to develop and demonstrate technology for economically feasible, environmentally acceptable and user-safe processes, techniques, and fluids that meet the operational requirements currently satisfied by halon 130...

The science of understanding how fires burn and how heat smoke and gases are generated and affect people has progressed substantially in the last half century. The principles of facility design for life safety in fires have reached a degree of maturity. Standards and code provisions for fire detection, suppression and control have become the norm....

Estimation of the time available for escape (ASET) in the event of a fire is a principal component in fire hazard or risk assessment. Valid data on the yields of toxic smoke components from bench-scale apparatus is essential to accurate ASET calculations. This paper presents a methodology for obtaining pre-flashover and post-flashover toxicant yiel...

For fire hazard and risk assessment, it is not practical to expect to find toxic potency values for all potential combustibles, nor is it reasonable to expect the assessment to include precise values, even if they were available. In large part, this is due to the limited degree of established precision and accuracy of toxic potency estimates at the...

Experiments have been conducted in the NFPA 269 / ASTM E1678 radiant apparatus to determine the sensitivity of toxic gas generation to atmospheric oxygen availability and to the conformation of the test specimen. CO and HCN generation can be dependent on the conformation of the test specimen. Thus, it is important that the test specimen exposure to...

Automobile fires are consistently among the largest causes of fire death in the United States (about 500 annually) and the U.S. motor vehicle industry and others have spent a significant amount of money in recent years studying this problem. The authors of this review have analyzed the auto industry reports, the scientific literature, and statistic...

This paper compares the responses of wall-size partition assemblies, composed of either type X or type C gypsum wallboard panels over steel studs, when each was exposed to an intense room fire. The exposures lasted from the time of ignition to beyond flashover. Heat flux gauges provided time histories of the energy incident on the partitions, while...

The U.S. Department of Defense (DoD) Next Generation Fire Suppression Program (NGP) was born of necessity. Atmospheric science had made it clear that fully halogenated compounds containing chlorine or bromine posed a threat to the earth’s ozone layer. An extensive, multi-year search by the DoD found that the best commercially available alternative...

A gypsum wall assembly was exposed to an intense real-scale compartment fire. For the wall assembly, temperatures were measured at the exposed face, within the stud cavity, and at the unexposed face during the fire exposure. Total heat flux gauges were used to measure the temporal variation of the energy incident on the walls, and cameras, both vis...

A glass wall assembly was exposed to an intense real-scale compartment fire. The wall assembly consisted of four glass sections, two of which were fitted with tempered double-pane glass and the other two sections were fitted with tempered single-pane glass. At each glass section, temperatures were measured at the exposed face and the unexposed face...

This paper presents the methodology for and results from a series of room-scale fire tests to produce data on the yields of toxic products in both preflashover and postflashover fires. Trays of common household electric cable burned in a room with a long adjacent corridor. The yields of CO 2, CO, HCl, HCN, and carbonaceous soot were determined. Oth...

A series of real-scale compartment tests was performed to provide information on the phenomenology of partition response and failure, to guide model development. Two partition assemblies of 2.44 m × 2.44 m were exposed to two intense fires from the time of ignition to beyond flashover. The assemblies were constructed using type X gypsum panels. The...

Many devices have been used to generate data on the toxic potency of smoke from burning products and materials. This paper critically reviews those apparatus and sorts them by the combustion conditions (related to a type of fire) producing the smoke, the specimens tested, and the animal effect measured. All the usable data were derived using rats,...

Fire hazard and risk analyses establish the basis for providing conditions of safety for people, including those that are more sensitive to fire smoke than others. For this purpose, this paper develops a method for estimating, from information on lethal and incapacitating exposures for rats, smoke toxic potency values for incapacitation of smoke-se...

Fire smoke toxicity has been a recurring theme for fire safety professionals for over four decades. There especially continue to be difficulty and controversy in assessing and addressing the contribution of the sublethal effects of smoke in hazard and risk analyses. The Fire Protection Research Foundation (FPRF), the National Institute of Standards...

Fires result from an ignition source meeting a flammable product. Fire or flame retardants are commonly added to polymeric products to slow or prevent ignition and to reduce the intensity of burning should ignition occur. This article provides an introduction to fire retardants. It presents reasons why fire retardants are useful, general mechanisms...

The Next-Generation Fire Suppression Program (NGP), now on its second year, has as its goal the development by 2004 of alternative firefighting technologies to Halon 1301 that can be economically implemented in aircraft, ships, land combat vehicles, and critical mission support facilities. This paper describes the first projects and their early res...

A comprehensive methodology has been developed for obtaining and using smoke toxicity data for fire hazard analysis. This description of the methodology comprises (1) determination that the post-flashover fire is the proper focus of smoke inhalation deaths; criteria for a useful bench-scale toxic potency (LC50) measurement method; (2) a method whic...

This paper reports an analysis of data from a study conducted by the cigarette industry to determine whether the fabrics used in a measurement method for cigarette ignition propensity reasonably represent the ignition behaviour of actual upholstery fabrics. A ‘consistency score’ is defined to evaluate objectively the relative agreement of ignition...

Research funded under the Fire Safe Cigarette Act of 1990 (United States Public Law 101–352) has led to the development of two test methods for measuring the ignition propensity of cigarettes. The Mock-Up Ignition Test Method uses substrates physically similar to upholstered furniture and mattresses: a layer of fabric over padding. The measure of c...

A key facet of the evaluation of new fire suppressants is their behavior under pressure and at elevated temperature in a metal storage container with an elastomer seal. In this study, 13 candidate chemicals have been examined: C2F6, C3F8, C4F10, cyclo-C4F8, CH2F2, C2HF5, CH2F2 (60%)/C2HF5 (40%), C2H2F4, C3HF7, C3H2F6, CHF2Cl, C2HF4Cl, and NaHCO3. T...

This paper identifies those fire conditions most often present when smoke toxicity is the cause of death. It begins with a review of the evidence that smoke-inhalation deaths are in the majority in fire fatalities in the United States. Next, there is an analysis of the evidence from the national fire experience showing the connection between post-f...

This project has developed measurement methods and provided data for the appraisal of 12 USAF-specified candidate halon 1301 replacements for compatibility with flight systems, people, and the environment. The exposures of metals, elastomers and lubricants involve an initial temperature and pressure of 298 K (77 OF) and 4.1 MPa (600 psi), with a fi...

This report is the principal product of a long-term research program to provide a technically sound methodology for obtaining and using smoke toxicity data for hazard analysis. It establishes:(a) an improved bench-scale toxic potency1 measurement, one which represents the important combustion conditions of real fires; and (b) a design and analysis...

It is clear that smoke toxicity is an important factor to consider in improving life safety during fires. However, to assess accurately the threat to people, the features of the fire, features of the building, the rate at which smoke is produced, the losses of that smoke, and the susceptibility of the building occupants must be considered. These co...

Halons 1301 and 1211 are being restricted by the Montreal Protocol of 1987. This project facilitates identification of alternative chemicals by developing quick, inexpensive screening procedures for nine critical properties: fire suppression efficiency, ozone depletion potential, global warming potential, residue level, toxicity, long-term storage...

The signing of the Montreal Protocol in 1987 demonstrated an international consensus that a variety of fully halogenated organic chemicals (halocarbons) were damaging stratospheric ozone. The current halogenated fire suppressants, or halons, were among the chemicals whose production is restricted by the Protocol. The likelihood of major reductions...

A sizable number of bench-scale fire toxicity tests have been pro posed over the last two decades. To date, no test method has successfully passed through the standards bodies ISO, ASTM, or BSI. The reasons are varied, but a major concern has been that none of the methods were seen to adequately pre dict the behavior of real, large-scale building f...

A full-scale fire performance protocol for the evaluation of school bus seat assemblies was developed. This protocol is based on the results of full-scale testing of end-use seat assemblies and computer fire modeling of the ignition source and burning item(s) in a single compartment enclosure. Tenability criteria were applied to the results of the...

Production of the currently-used halogenated fire suppressants (halons) will be curtailed because of their contribution to stratospheric ozone depletion. The report, one of the first efforts toward identifying alternatives, documents the rationale for and selection of a set of approximately one hundred gases and/or liquids, covering a range of chem...

A long range goal of fire science is to be able to predict "real- world" fire performance from a small set of laboratory scale fire measurements. One material property of primary concern is the toxicity of decomposition prod ucts. Several small scale toxicity protocols that measure toxic potency of the smoke from burning materials have been develop...

Changes in the propensity of cigarettes to ignite upholstered furniture and bedding could reduce fire losses significantly. This paper describes fundamental and empirical studies of the effect on ignition propensity of varying cigarette characteristics. Reduced tobacco density, circumference and paper porosity were especially effective. Energy tran...

Larger scale studies of liquid pool fires involved varying the pool surface area and depth, the chamber size and geometry, the pressurization rate, and the fuel and fuel temperature. Fuel-oxidant mixing and fuel temperature are the primary determinants of how much nitrogen is needed for flame suppression. In the worst cases, turbulent fires of boil...

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The rate constant for the reaction of oxygen atoms with CF3Br (halon 1301) was measured at low pressures in a heated discharge‐flow reactor. The halon concentration was followed gas chromatographically. The likely primary reaction products are CF3 and OBr radicals. Variation of experimental parameters and correlated numerical solutions of the total...

Laboratory experiments on pressurization with nitrogen as a technique for suppressing fires in gastight spaces have been extended to solid fuel combustion. Flames from fabric and cellulosic fires in a 9.5 ft chamber were quenched by the addition of ≲ 0. 5 atm of nitrogen. Several samples of each fuel were allowed to burn to self-extinguishment in t...

Pressurization with nitrogen has been studied as a technique for suppressing fires in confined spaces. Liquid hydrocarbon-air fires of various sizes in a gastight experimental chamber were extinguished in approximately 30 seconds by increasing the total pressure of the enclosure from l atm. to 1.35 ± 0.03 atm. The post-fire atmospheres were found t...

An average cross section for the title reaction has been computed from certain previously reported hot atom (photochemical-recoil) data. The cross section is equal to 1.6 ± 0.3 Å2, and it is defined as SR(E)HBr = ∫0.351.7 h′(E)SR(E)dE, where SR(E) is the corresponding microscopic quantity and h′(E) is a known normalized distribution function of ene...

The excitation function for the formation of HD was determined by means of a nonequilibrium bulb method in the relative energy range of ∼ 0.5–1.7 eV. Hydrogen atoms of various well‐known initial kinetic energies, 0.35, 0.48, 0.67, 0.92, 1.15, 1.67, and 2.05 eV, were generated by the photodissociation of HI and HBr in the presence of either n‐C4D10...

Durch Photodissoziation von HJ oder HBr wurden H-Atome bekannter kinetischer Anfangsenergie erzeugt.

At the request of the Under Secretary of Defense (Acquisition, Technology and Logistics), the Director of Defense Research and Engineering convened an Independent Review Panel (IRP) to assess the four critical technical issues and comment on how they might affect implementation of CF3I as a viable substitute for halon 1301 in the F-16 inerting appl...

It has been known for decades that people die from inhaling fire gases and that visible smoke presents challenges to people trying to escape from fires in homes, transportation vehicles, and commercial buildings. Within the current decade, there has been an invigorated effort, especially in ISO TC92 SC3, Fire Threat to People and the Environment, t...

A method for extrapolating the time dependent heat release rates obtained from Cone Calorimeter measurements is presented. This method is implemented by fitting model parameters to experimental heat release rate data obtained at a specified level of irradiance and evaluating the resulting function at the values of interest. The method was validated...

Typical prescriptive and performance-based assessments of life safety in building fires do not explicitly consider the contributions of the toxic potency of combustion gases, smoke obscuration, or the thermal and radiative environment. This paper characterizes two approaches (one rigorous and one simplified) to fire hazard assessment that include t...

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