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General PCBs Information

PCBs are a group of man-made organic chemicals consisting of carbon, hydrogen and chlorine atoms. The number of chlorine atoms and their location in a PCB molecule determine many of its physical and chemical properties. PCBs have no known taste or smell, and range in consistency from an oil to a waxy solid.

Historic Information

PCBs belong to a broad family of man-made organic chemicals known as chlorinated hydrocarbons. PCBs were domestically manufactured from 1929 until manufacturing was banned in 1979 under the Toxic Substances Control Act (TSCA). They have a range of toxicity and vary in consistency from thin, light-colored liquids to yellow or black waxy solids. Due to their non-flammability, chemical stability, high boiling point and electrical insulating properties, PCBs were used in hundreds of industrial and commercial applications including:

  • Electrical, heat transfer and hydraulic equipment
  • Plasticizers in paints, plastics and rubber products
  • Pigments, dyes and carbonless copy paper
  • Other industrial applications

Current Production

Following the manufacturing ban, PCBs continue to be inadvertently produced as a by-product of other manufacturing processes at levels below the TSCA ban requirements. Chemical processes which combine heat and chlorine, often in the form of hydrochloric (muriatic) acid can generate very low levels of PCBs. Many household products involve this step at some point in their manufacturing. As long as levels are below the TSCA limit, products are allowed to be labeled “PCB Free”.

A Note on Regulations

PCBs have special disposal requirements when they are present in concentrations greater than 50 parts per million. The EPA instituted this rule, and the production ban, to protect human health by minimizing direct exposure to PCBs. PCBs below this level are not regulated for storage or disposal by TSCA. Generally, products manufactured after the 1979 ban will not have PCBs at a level which is regulated for special disposal requirements.
Water quality regulations are based on a different exposure pathway – fish consumption by humans. PCBs tend to build up in tissue over time. If PCBs are present in water, small animals will accumulate them to a certain level. This buildup is magnified as the small animals are consumed by larger animals up the food chain. In this way, it is possible for relatively low concentrations in water to contaminate fish at levels which might present a risk to humans when consumed.
Water quality regulations are intended to protect human health by avoiding concentrations which could lead to unhealthy levels of PCBs in fish. Depending on local regulations, this value ranges from 294 million to 41 billion times lower than the EPA TSCA limits.


The City of Post Falls operates a Water Reclamation Facility which removes most contaminants from wastewater before returning to the Spokane River. Although the treatment plant is not specifically designed for PCB removal, it typically removes about 99% of PCBs received from the sewer system. Households and businesses can decrease the PCBs both sent and discharged by reducing their own contributions to the system.


In a few parts of the City, rainwater and snowmelt run directly into pipes which convey it to the Spokane River. If pollutants accumulate in areas where rainwater travels, they can be washed into the river as well.

How to Help

Some common sense, easy to implement tasks can decrease each person’s PCB contribution to the environment. When disposing of waste, especially solvents and other chemicals, make sure to follow the recommended procedures for that material. Dumping any sort of chemical waste into the sewer system is not proper. Solid wastes should be disposed of via a municipal solid waste program, unless there is a reason to suspect they contain PCBs at a level greater than the TSCA limit. In that case, follow EPA’s recommended guidance. Minimizing waste in general by procuring only the amount of material needed for a task, can also reduce PCB contributions. Good housekeeping practices at construction sites will help to keep dust and debris from accumulating where they can be washed away by stormwater. Special care should be taken on sites with pre-1980’s construction to avoid allowing any PCB containing materials to leave the site, even in the form of dust.

A Note on Safety

It can be concerning to learn that PCBs exist at low levels in many products. Neither health agencies nor regulatory agencies are indicating that direct exposure at these low levels poses a risk to human health. The concern with the low level PCBs is the overall risk to the environment and the potential to accumulate in fish.

More Information

A wealth of information can be found on the internet regarding PCBs. When researching, remember to consider the source and to seek guidance from reputable, science-based groups.
Spokane Waste Directory
Washington Department of Ecology
Toxics Management Plan
2020 Toxics Managements Plan Annual Report
2019 Toxics Managements Plan Annual Report
2018 Toxics Managements Plan Annual Report
2017 Toxics Management Plan Annual Report
Spokane River PCB Free
PCB BMPs for Demolition and Remodeling

This page was created as part of the City of Post Falls’ NPDES permit obligations. It is intended to serve as a part of the Public Education program to educate the public about the following:
(i) The difference between products free of PCBs and those labeled non-PCB but which contain PCBs below the TSCA regulatory threshold of 50 ppm.
(ii) Proper disposal of waste products that may contain PCBs including those containing PCBs below the TSCA regulatory threshold of 50 ppm and the hazards associated with improper disposal.