14 / 2022-02-22 08:41:20

Review of available health and safety data on leading SF6 alternative gases mixtures

Health,Safety, SF6 alernative gases

Review of available health and safety data on leading SF₆ alternative gases mixtures

Rainer Kurz¹, Rudi Van San², John Owens³, Jason Bonk³, Michael DeLorme³, Agnes Zhang<sup>4

1</sup>  3M Deutschland GmbH, Neuss, Germany

²  3M Belgium BVBA, Zwijndrecht, Belgium

³  3M Company, St. Paul, USA<sup>2 

4</sup>  3M China, Shanghai, China 



One of the continuing environmental challenges for the electric power industry results from the use of sulfur hexafluoride (SF₆) as a dielectric medium in gas-insulated equipment. For several decades, SF₆ has been the preferred technology for electrical insulation and arc interruption, particularly in high voltage equipment. However, since the early 1990s, SF₆ has become recognized as the most potent greenhouse gas due to its long atmospheric lifetime (3,200 years) and resulting high global warming potential (23,500). As a result, the use and emissions of SF₆ into the atmosphere have been tracked by multiple international organizations. Despite successful industry efforts to reduce the rate of emissions from equipment, the atmospheric concentration of SF₆ has continued to steadily increase. In recognition of this, the electric power industry has long searched for alternative insulating gases to replace SF₆. In recent years, a fluoroketone and a fluoronitrile have begun to be implemented within gas mixtures to replace SF₆ in new equipment designs for certain voltage classes. Gas-insulated equipment containing these new alternatives are currently operating on the grid, primarily in Europe but with installations also beginning in Asia and North America.



This paper reviews the available health and safety data on these alternative gases and the parameters required to perform a risk assessment for their use in electric power applications.

Both compounds have been evaluated through a series of toxicological studies and were demonstrated to be low in acute inhalation toxicity, the primary mode of potential exposure in gas insulated system applications. Based upon all the available data, as well as independent third-party assessment, both compounds demonstrated no genotoxicity potential and are not expected to be classified as a carcinogenic, mutagenic, reproductive toxicity (CMR) hazard.



In view of these toxicological profiles, risk assessments were conducted on the use of these compounds in gas-insulated equipment taking into account the potential for worker exposure.

The concentrations of insulating gas typically measured near electric power equipment are well below the occupational exposure limits established for these SF₆ alternatives. Under normal operating conditions, as well as with used gas after arcing, the hazards and potential exposures were found to be similar to those observed with SF₆ in comparable scenarios, thus, posing similar risks. On this basis, the precautions and personal protective equipment currently employed with new and used SF₆ have been recommended for use with these SF₆-alternative gas mixtures. As a result, these alternative gases and their mixtures provide the necessary margin of safety required for these applications.