PDF(Pubmed)
Abstract：
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.
摘要：
消防员或教官在实弹训练期间接触空气中的化学物质可能取决于燃烧的燃料，燃料方向和参与者在结构中的位置。这项研究旨在评估在将燃料包安装在天花板上或附近的火灾动力学培训期间，不同控制措施对燃烧副产物暴露风险的影响。这些措施包括替代训练燃料(低密度木纤维板，定向刨花板（OSB），托盘,刨花板,胶合板）并采用工程控件，例如更改使用结构的讲师和学生的位置。在两个不同的训练持续时间内进行了实验：典型的六个通风循环（6循环）和带有训练燃料子集的较短的三个通风循环（3循环）。在本系列的A部分中,我们描述了结构内的火灾动力学，包括每种燃料提供实现培训目标的环境的能力。这里,在B部分,空气中的化学物质浓度是在消防教练通常工作的位置报告的。我们假设，与包含其他树脂和/或蜡的人造板产品相比，使用带有实木托盘的训练燃料包将导致后方教练位置的空气传播污染物浓度更低。在6个周期的实验中（在后教练位置），OSB燃料火灾产生的苯和1,3丁二烯的中值浓度最高，胶合板燃烧的火灾产生了最高的总多环芳烃（PAH）浓度，刨花板燃烧的火灾产生了最高的异氰酸甲酯浓度，和托盘燃料的火灾产生最高的氯化氢浓度。除刨花板以外的所有燃料在后方教练位置产生类似的高水平甲醛。OSB燃料包在6个循环中创造了最一致的火灾动力学，而纤维板仅在前三个循环中产生一致的火灾动力学。在随后的3周期实验中，PAH,苯,OSB和纤维板燃料火灾的醛浓度相似。空气采样没有发现燃烧实木托盘的训练用火与将这种常用燃料布置的人造板产品与在舱室中安装较高的燃料相结合的训练用火之间有任何明显差异。然而,发现可以通过将消防员和教练在隔间中降低和/或将负责通风的教练从结构的后部（始终测量最高浓度）移动到外部位置来减少暴露。
