Assessment on the toxicity and application risk of C4F7N: A new SF6 alternative gas.

CFN (fluorinated nitrile) gas mixture has been utilized as the gas insulating medium to replace the most greenhouse gas SF (sulphur hexafluoride). Nowadays, there are few reports on the toxicity mechanism of CFN and studies on the application risk of CFN is insufficient. In this paper, we carried out acute toxicity tests for CFN gas systematically. The changes of vital signs of rats after exposure to CFN were analyzed and the influence of CFN on the main organs of rats was revealed for the first time. It was found that rats developed symptoms of respiratory rate decrease, respiratory mucosa damage, movement systems impairment and abnormal blood cell count after exposure to CFN. Pathological section results showed that 1.5% CFN could damage the lung, kidney, intestine and brain tissues of rats to a certain extent, but has little influence to the eye, skin, heart and liver. The LC50 (rat, 4 h) of CFN gas is in the range of 15,000 ppm (1.5%) and 20,000 ppm (2%). Relevant research results not only reveal the acute toxicity mechanism of CFN, but also provide important reference for the safety protection of scientific researcher, equipment production, engineering operation and maintenance personnel.