At present, reports on the arc interruption and decomposition behavior of a C₄F₇N/air gas mixture especially the biosafety of its by-products are limited. Herein, a 57% C₄F₇N/43% air gas mixture was employed as an arc-quenching medium to conduct 200 breaking tests on a load switch (630 A/24 kV). The arc interruption and decomposition behavior of the gas mixture were evaluated, and the biosafety of the decomposition products was assessed based on an acute inhalation toxicity test. It was found that the average arcing time of the 200 breakings was about 10.1 ms and that breakings were basically completed at the zero-crossing of the second or third current half-cycle. The gas mixture after breaking decomposed dramatically (the C₄F₇N content decreased by 75.6%), generating a large number of gaseous by-products (CO, CF₄, C₂F₆, C₃F₈, CF₃CN, C₄F₈, CO₂, C₄F₁₀N₂, C₃F₆, C₂N₂, etc.) as well as solid by-products (carbon particles). The lethal concentration of 50% (LC50, 4 h) of C₄F₇N/air after 200 breakings was 31 ppm (male mice) and 34 ppm (female mice), respectively, and the toxicity was classified as Grade 1. In general, C₄F₇N has an arc interruption capability, albeit weaker than that of SF₆ under the same conditions. After breaking, the C₄F₇N gas mixture has a relatively high acute inhalation toxicity, and relevant safety protection measures for research or operation personnel are strictly needed.

中文翻译：

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C4F7N/Air气体混合物的电弧分解行为及其副产物的生物安全性评价

目前，关于C ₄ F ₇ N/空气气体混合物的电弧中断和分解行为，特别是其副产物的生物安全性的报道有限。本文采用 57% C ₄ F ₇ N/43% 空气混合气体作为灭弧介质，对负载开关 (630 A/24 kV) 进行 200 次分断试验。评估了气体混合物的电弧中断和分解行为，并根据急性吸入毒性试验评估了分解产物的生物安全性。发现200次分断的平均燃弧时间约为10.1 ms，分断基本在第二或第三个电流半周期的过零处完成。破裂后的气体混合物急剧分解（C₄ F ₇ N含量下降75.6%），生成大量气态副产物（CO、CF ₄、C ₂ F ₆、C ₃ F ₈、CF ₃ CN、C ₄ F ₈、CO ₂、C ₄ F ₁₀ N ₂、C ₃ F ₆、C ₂ N ₂等）以及固体副产物（碳颗粒）。50%（LC50，4 h）的C ₄ F _{7致死浓度}N/air 200 次断裂后分别为 31 ppm（雄性小鼠）和 34 ppm（雌性小鼠），毒性分类为 1 级。总体而言，C ₄ F ₇ N 具有电弧中断能力，尽管比它弱SF ₆在相同条件下。_{C 4} F ₇ N 气体混合物破裂后具有较高的急性吸入毒性，需要对科研或操作人员采取相关的安全防护措施。