PCB Overview
Date Requested: May 23 2019 8:20 AM


What are PCBs?
Polychlorinated biphenyls (PCBs) belong to a broad family of organic chemicals known as chlorinated hydrocarbons. The commercial production of PCBs began in 1929 and they were widely used as ingredients in the manufacture of heat transfer fluids, hydraulic fluids, and dyes and as cooling and dielectric fluids in electrical transformers, light ballasts, and electrical capacitors.

In the 1970's, Congress concluded, after completing one study that observed the effect of PCBs on mice, that PCBs could pose a threat to human health and the environment and issued a ban against the further production of PCBs. As a result of the ban, PCBs were last manufactured on an industrial scale in the U.S. in 1979.
Through the normal course of operating a natural gas pipeline system, pipeline liquids, mostly in the form of hydrocarbons, can drop out of the gas stream and accumulate throughout a pipeline network. Some of these liquids may contain Polychlorinated Biphenyls (PCBs).   Until 1979, there were many sources of PCBs in the natural gas pipeline industry. Some pipeline companies used valve sealant that contained PCBs; some used turbine oil that contained PCBs and some fogged their lines with waste oil that contained PCBs.

What is Northern doing to control PCBs in the pipeline system?
Northern Natural Gas has installed filters at some locations and will continue to install filters in the future where liquids are found. If these liquids are captured, then the PCBs are also captured with the liquids.  Northern Natural Gas is also pigging many of the lines to remove liquids that may be residing in the system.   Northern Natural Gas has had a PCB management program in place since 1981. This program includes annual sampling of several liquid collection points and installing liquid collection appurtenances where required. Controlling the liquid movement throughout the pipeline system controls the migration of PCBs, if present.

Contact for more information
If you have additional questions regarding PCBs, please email or call your account representative or contact michael.loeffler@nngco.com

PCB - Fast Facts
PCB - History and Overview
Health effects of exposure to PCBs
Frequently Asked Questions


As noted in this document, the health studies cannot definitively correlate occupational exposure to PCBs with any type of cancer.

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