Experimental data from compartment fires with gas burner and upholstered furniture fuels.

There exists a variety of specialized fire dynamics routines, zone fire models, and field fire models. Many of these heuristics and correlations rely on experimental data from fires fueled by gas burners or liquid pool fires and have had minimal, if any, validation against data from fires with solid, more complex fuels, such as upholstered furniture. One hundred and twenty fire experiments were conducted inside a compartment that contained a single ventilation opening in the form of a doorway that was either open or closed for the entirety of each experiment. The fires were fueled by natural gas burners and upholstered furniture items. The compartment was instrumented throughout with thermocouples, oxygen sampling probes, heat flux gauges (total and radiative), pressure transducers, and bi-directional probes. Additionally, heat release rate data were collected during open door experiments with fires larger than 100 kW. This experimental series was designed to better quantify the repeatability of and differences between natural gas burner and upholstered furniture fuels and to provide new validation cases for the fire modeling community.

Exposure Risks and Potential Control Measures for a Fire Behavior Lab Training Structure: Part B. Chemical Gas Concentrations.

Firefighters' or instructors' exposure to airborne chemicals during live-fire training may depend on fuels being burned, fuel orientation and participants' location within the structure. This study was designed to evaluate the impact of different control measures on exposure risk to combustion byproducts during fire dynamics training where fuel packages are mounted at or near the ceiling. These measures included substitution of training fuels (low density wood fiberboard, oriented strand board (OSB), pallets, particle board, plywood) and adoption of engineering controls such as changing the location of the instructor and students using the structure. Experiments were conducted for two different training durations: the typical six ventilation cycle (6-cycle) and a shorter three ventilation cycle (3-cycle) with a subset of training fuels. In Part A of this series, we characterized the fire dynamics within the structure, including the ability of each fuel to provide an environment that achieves the training objectives. Here, in Part B, airborne chemical concentrations are reported at the location where fire instructors would typically be operating. We hypothesized that utilizing a training fuel package with solid wood pallets would result in lower concentrations of airborne contaminants at the rear instructor location than wood-based sheet products containing additional resins and/or waxes. In the 6-cycle experiments (at the rear instructor location), OSB-fueled fires produced the highest median concentrations of benzene and 1,3 butadiene, plywood-fueled fires produced the highest total polycyclic aromatic hydrocarbon (PAH) concentrations, particle board-fueled fires produced the highest methyl isocyanate concentrations, and pallet-fueled fires produced the highest hydrogen chloride concentrations. All fuels other than particle board produced similarly high levels of formaldehyde at the rear instructor location. The OSB fuel package created the most consistent fire dynamics over 6-cycles, while fiberboard resulted in consistent fire dynamics only for the first three cycles. In the follow-on 3-cycle experiment, PAH, benzene, and aldehyde concentrations were similar for the OSB and fiberboard-fueled fires. Air sampling did not identify any clear differences between training fires from burning solid wood pallets and those that incorporate wood-based sheet products for this commonly employed fuel arrangement with fuels mounted high in the compartment. However, it was found that exposure can be reduced by moving firefighters and instructors lower in the compartment and/or by moving the instructor in charge of ventilation from the rear of the structure (where highest concentrations were consistently measured) to an outside position.

Airborne contamination during post-fire investigations: Hot, warm and cold scenes.

Fire investigators may be occupationally exposed to many of the same compounds as the more widely studied fire suppression members of the fire service but are often tasked with working in a given exposure for longer periods ranging from hours to multiple days and may do so with limited personal protective equipment. In this study, we characterize the area air concentrations of contaminants during post-fire investigation of controlled residential fires with furnishings common to current bedroom, kitchen and living room fires in the United States. Area air sampling was conducted during different investigation phases including when investigations might be conducted immediately after fire suppression and extended out to 5 days after the fire. Airborne particulate over a wide range of dimensions, including sub-micron particles, were elevated to potentially unhealthy levels (based on air quality index) when averaged over a 60 min investigation period shortly after fire suppression with median PM2.5 levels over 100 µg/m3 (range 16-498 µg/m3) and median peak transient concentrations of 1,090 µg/m3 (range 200-23,700 µg/m3) during drywall removal or shoveling activities. Additionally, airborne aldehyde concentrations were elevated compared to volatile organic compounds with peak values of formaldehyde exceeding NIOSH ceiling limits during the earliest investigation periods (median 356 µg/m3, range: 140-775 µg/m3) and occasionally 1 day post-fire when the structure was boarded up before subsequent investigation activities. These results highlight the need to protect investigators' airways from particulates when fire investigation activities are conducted as well as during post-fire reconstruction activities. Additionally, vapor protection from formaldehyde should be strongly considered at least through investigations occurring 3 days after the fire and personal formaldehyde air monitoring is recommended during investigations.

Gas burner experiments conducted in modern residential style structures.

The fire modeling community currently lacks full-scale data from tests conducted in realistic residential-style structures. Controlled gas burner tests were conducted in purpose-built single- and two-story structures instrumented throughout with thermocouples, pressure transducers, and bi-directional probes. Experiments consisted of sequences of ventilation events. The data collected in these tests was intended to provide several new validation cases for the fire modeling community.

Standards in Biologic Lesions: Cutaneous Thermal Injury and Inhalation Injury Working Group 2018 Meeting Proceedings.

On August 27 and 28, 2018, the American Burn Association, in conjunction with Underwriters Laboratories, convened a group of experts on burn and inhalation injury in Washington, DC. The goal of the meeting was to identify and discuss the existing knowledge, data, and modeling gaps related to understanding cutaneous thermal injury and inhalation injury due to exposure from a fire environment, and in addition, address two more areas proposed by the American Burn Association Research Committee that are critical to burn care but may have current translational research gaps (inflammatory response and hypermetabolic response). Representatives from the Underwriters Laboratories Firefighter Safety Research Institute and the Bureau of Alcohol, Tobacco, Firearms and Explosives Fire Research Laboratory presented the state of the science in their fields, highlighting areas that required further investigation and guidance from the burn community. Four areas were discussed by the full 24 participant group and in smaller groups: Basic and Translational Understanding of Inhalation Injury, Thermal Contact and Resulting Injury, Systemic Inflammatory Response and Resuscitation, and Hypermetabolic Response and Healing. A primary finding was the need for validating historic models to develop a set of reliable data on contact time and temperature and resulting injury. The working groups identified common areas of focus across each subtopic, including gaining an understanding of individual response to injury that would allow for precision medicine approaches. Predisposed phenotype in response to insult, the effects of age and sex, and the role of microbiomes could all be studied by employing multi-omic (systems biology) approaches.

Characterization of Stovetop Cooking Oil Fires.

A series of cooking fire experiments were conducted by the National Institute of Standards and Technology (NIST) to examine the hazard associated with cooking oil fires. First, a series of twelve experiments were conducted on a free-standing stove situated in the open. The experiments were based on scenarios outlined in the draft UL 300A standard for fire suppression apparatus. Both gas and electric ranges were tested. The amount of oil and types of cooking pans were varied in the experiments. Oil was heated on a cook top burner until autoignition took place. Measurements of oil and pan temperatures, heat release rates, and heat fluxes characterized the hazard of the ensuing fires. Next, two experiments were conducted using a full-scale residential kitchen arrangement to examine the hazard associated with the free burning oil fires situated within a compartment equipped with commercial furnishings, fiberboard cabinets, and countertops. The dimensions of the test room were 3.6 m × 3.4 m × 2.4 m high. Corn oil was heated on a cook top burner until autoignition took place. Measurements of room temperatures, heat fluxes, and heat release rates showed that even small cooktop fires spread and grew ultra-fast within the kitchen compartment.