Acute Inhalation Toxicity Studies of Gas Insulating Medium C4F7N

At present, there are few reports on the toxicity of the new type gas insulating medium C4F7N, which brings hidden trouble for the safety of scientific research and engineering application. Therefore, we explored the acute inhalation toxicity of C4F7N/air mixture gas with different C4F7N content using a gas toxicity test platform. The changes of vital signs of rats after exposure in C4F7N were analyzed. Combined with the test results, the protection suggestions for scientific researchers and equipment maintenance personnel were also discussed. We found that rats showed symptoms from calm to active, and then hyperactive and uneasy after exposed to 1.5% C4F7N. The rats lost their exercise capacity and cannot move independently after 1-h exposure. Their eyes were closed and the breathing rate is slow with convulsions and other symptoms. All the rats exposed to the gas environment with a C4F7N content of 1% to 1.5% for 4 hours and then transferred to the feeding environment returned to normal after 96 hours. The dead samples can be found after exposed to the gas environment with a 2% C4F7N for 4 hours and then subject to a 14-day recovery period. Based upon the data presented in the current study, the 4-hour LC50 of C4F7N is in the range of 1.5%-2%. Based upon the 4-hour exposure LC50 results, C4F7N gas is classified in Category 4 in the Globally Harmonized System (GHS) for acute toxicity. The industrial hygiene practices required to handle decomposed SF6 are similar to those required for decomposed C4F7N gas mixture. © 2019, High Voltage Engineering Editorial Department of CEPRI. All right reserved.