Progress on the environment friendly insulation gases for replacement of SF

6

has been reviewed including both unity gases and gaseous mixtures. Criteria for the physical chemical properties

environmental effect

and dielectric features of the alternative gases are proposed. In the consideration of ozone depletion

no chlorine or bromine should be involved in the molecular structures. The perspective of the SF

6

replacement is presented as well. It is suggested that the theoretical study of the novel alternative gases using quantum chemistry methods should be taken into account in a long-term research plan. Meanwhile

rational design on the basis of the available insulation gas mixtures appears

to be a promising approach for SF

6

replacement.