ACS Chemical Health & Safety最新文献

Development of laboratory safety programs often focuses on the tools and policies needed to protect people, the environment, and equipment. Tools and policies are unlikely to result in meaningful positive safety outcomes alone. Effective engagement is a critical component, and this can only be achieved by nurturing an effective safety culture. Merriam-Webster offers one definition of culture as, “the set of shared attitudes, values, goals, and practices that characterizes an institution or organization” (emphasis added), and employee engagement and leadership support are equally critical to safer laboratories. This commentary begins with a discussion of how human beings perceive work, individual and organizational performance heuristics, and the ways in which policies and procedures influence individual behavior and how individual engagement in safety programs can influence organizational change, resulting in evolutionary improvements in approaches to laboratory safety. We then offer examples of tools and engagement that have been used at Dow to achieve those goals.

The gas explosion induced by the high-temperature surface of coal spontaneous combustion in goaf will cause a devastating blow to personnel and equipment in the process of coal mining. Secondary explosion may be induced by the high-temperature surface of coal spontaneous combustion after primary explosion with the continuous emission of gas and the ventilation of goaf. This will lead to new disasters for the ongoingrescue operation. A high-temperature source explosion experimental system consistent with the similarity and unity of goaf was designed and developed based on the similarity criterion in this study. A CH₄/air explosion experiment was carried out with the high-temperature surface as an ignition source. The characteristics of secondary explosion were studied, and chemical kinetics was analyzed. It is of great significance to the safety of the process of mining production. The results show that the secondary explosion limit (6.5–14%) is less than the primary explosion (5.5–14.5%). Its explosion risk (F) is reduced by 15.6%. The key parameters P_max, T_max, and (dP/dt)_max of secondary explosion at each concentration are lower than those of primary explosion. The t_e of secondary explosion is higher than primary explosion. The most dangerous concentration of primary and secondary explosions induced by the high-temperature surface is 11.5%. Carbon oxides (CO₂ and CO) and C₂ hydrocarbon gases (C₂H₂, C₂H₄, and C₂H₆) are generated after primary explosion. The chemical kinetics of secondary explosion was analyzed with CHEMKIN Pro 2021. When the CH₄ concentration is <11.5%, the formation of the key free radicals ·H, ·O, ·OH, and CH₂O is inhibited due to the formation of CO₂. When the CH₄ concentration is ≥11.5%, the formation of the key free radicals ·H, ·O, ·OH, and CH₂O is inhibited due to the generation of combustible gases (C₂H₂, C₂H₄, C₂H₆, and CO) and inert gas (CO₂). As a result, the limit range of secondary explosion and the explosion hazard characteristics are reduced. R156 and R158 played major roles in the process of secondary explosion with the analysis of reaction sensitivity.

After decades of research, the biological effects of tritium have been basically clear. Compared with many studies on tritium biology and RBE value, the research on the toxicity mechanism is relatively lacking. Previous research on the mechanism of tritiated water toxicity focused on oxidative stress, cell apoptosis, and DNA damage, but the specific molecular mechanism is lacking. With the development of molecular biology technology, it has become possible to elucidate the molecular mechanism of internal tritium radiation damage at multiple levels. In this paper, we reviewed our studies over the past ten years to clarify the mechanism of tritium toxicity from different aspects such as miRNA, DNA methylation, and gene expression changes. Some key target molecules were found and tried to be used to evaluate the tritium toxicity.

Numerous published and anecdotal accounts exist on flammable liquids and gases igniting in chemical laboratories. This hazard could be mitigated by a better understanding of the principles behind electrical classification, which determines the type of electrical equipment that can be safely used in the presence of flammable materials. Laboratories can successfully apply electrical classification to reduce the risk of fires and explosions, but its proper application requires experience in research operations, the principles and practices of area electrical classification, proper hazard analysis and risk assessment, and some understanding of the methods available for compliance. This article provides a primer for laboratory personnel to assist them in determining if electrical classification of their operations and equipment may be warranted.

Accidents involving the transportation of hazardous materials (hazmats) may cause fatalities, injuries, and property damage along the transport route. It is thus imperative to adopt and implement a risk assessment and management framework that can be easily employed by decision/policymakers. This paper presents a quantitative risk assessment (QRA) framework to select the safest route for the transport of hazardous materials utilizing an accident database and human vulnerability models. Statistical models from relevant accident studies are used to determine the accident enhancing/mitigating contributions of different road geometrical features, which are then applied to data derived from an available database to determine accident frequencies. Consequences of accidents with humans are assessed using ALOHA and vulnerability models, while the risk is determined by combining both accident frequencies and consequences. The proposed method has been applied in a case study to assess the relative risks involved in LPG transportation along two different routes in Bangladesh and to identify the safer route. The effectiveness of a number of risk reduction measures has been assessed to manage risks, and the results of the risk assessment have been spatially presented on a geographical map. This map will help decision makers to make routing decisions and identify route sections that are most at risk to take appropriate emergency response actions and allocate medical and support services during emergencies.