C

4

F

7

N gas mixture is an environmentally-friendly insulating medium with wide attention. For assuring the safety of its application in electric power industry

it is necessary to perform an in-depth assessment of the acute inhalation toxicity of the C

4

F

7

N gas mixture. In this paper

the symptom of the mice after exposure to C

4

F

7

N gas mixture and the physiological recovery characteristics of the surviving mice are revealed by means of

the test result of 4 h acute inhalation C

4

F

7

N gas mixture. The results show that the median lethal concentration (

LC

50

) of C

4

F

7

N gas mixture is 1 270 μL/L (4 h

mice). It is found in combination with weight variation and blood test result that the surviving mice after exposure to C

4

F

7

N at a concentration of 1 000 μL/L could return to normal condition after the 14 days observation period. The acute inhalation toxicity of the C

4

F

7

N gas mixture is systematically assessed by the relevant result

which can provide important reference for its engineering application.