When it comes to medium and high voltage circuit breakers, there is no better electrical insulator than sulfur hexafluoride (SF6). Unfortunately, the same properties that make SF6 such a great insulating gas also make SF6 the most potent of all greenhouse gases. With the ever-growing challenges of federal & local reporting and a shift towards more eco-friendly practices, the industry is seeking ways to reduce SF6 emissions.

One way to curb emissions is to switch to the use of reconditioned SF6 gas instead of purchasing virgin SF6 gas. The production of virgin SF6 gas was ceased in the United States with the greenhouse gas emission reduction targets instituted by the Environmental Protection Agency. Therefore, virgin SF6 gas purchased in the United States is be imported from Russia or Asia, where the gas is produced. There is a large, growing stockpile of SF6 gas in North America. From an environmental perspective, reconditioning gas helps us to lower the carbon footprint by removing the need to produce more SF6 gas. The production of SF6 is a known source of underlying emissions.

DILO- SF6 Gas (sulfur hexafluoride) molecule

According to the Environmental Science & Technology Report1, SF6 production in China contributed to 10 percent of annual SF6 gas emissions from the country between 1990 and 2010. In fact, producing virgin SF6 gas can create 12.5 or more times the emissions than reconditioning or recycling SF6 gas for re-use.

DILO- Comparison of Emission Rates for Virgin, Reconditioned, and Recycled SF6 Gas

(1) Virgin SF6 Gas, which is batch tested (analyzed) to be at a purity of 99.9%, delivered into North America

(2) Reconditioned SF6 Gas, which is analyzed to be at a purity of 95% and is reconditioned using DILO SF6 gas separation processor and the DILO SF6 gas handling procedures that limit emissions, to a reconditioned purity of =/>99.0%

(3) Recycled SF6 Gas, which is analyzed to be at a purity of =/>97% and is recycled using the applicable DILO recovery system and the DILO SF6 gas handling procedures that limit emissions.

Any contaminants that may occur while SF6 gas is in use, due to the intrusion of air, moisture, or generation of arc-byproducts, can be removed with the proper filtration and separation process. The reconditioning practice of SF6 ensures readily available supply for the power and utility sectors and eliminates the need for importing virgin product.

An additional advantage for sourcing reconditioned SF6 is cost savings. Virgin gas is typically sold at a premium and guarantees a greater than 99.99 percent purity rating. Technological advances in the filtration and separation process make it possible for reconditioned SF6 to meet/exceed federal and international industry standards, all at a lower cost. This cost savings does not compromise quality. Whether your SF6 supply is restocked with greater than 99 percent or “5/9 gas” (99.999 percent), the result is the same: a circuit breaker filled with a reliable medium that requires minimal maintenance.

You can find more information on the emissions produced in the production of virgin, reconditioned,  and recycled SF6 gas in our latest whitepaper, Alternative Options: Reconditioned & Recycled Versus Virgin SF6 Gas”.

DILO Certified Reconditioned SF6 Gas Information



1 Hu Jianxin, et al. “Sulfur Hexafluoride (SF6) Emission Estimates for China: An Inventory for 1990-2010 and a Projection to 2020.” Environmental Science & Technology, April 2013, Vol. 47, Issue 8, pp 3848−3855.