PBT photo identifier


What are Polychlorinated Biphenyls (PCBs)?

New! Product testing report: Polychlorinated Biphenyls in Consumer Products - Full report | Focus sheet

PCBs are a group of 209 manmade compounds that generally occur as complex mixtures. While historically the largest use of PCBs was in electrical equipment, there are many other sources of PCBs. PCBs are very persistent, lasting for decades in the environment. Like other persistent, bioaccumulative, and toxic chemicals, PCBs move easily between air, water and land, so they are found throughout Washington. PCBs also accumulate in people and animals, becoming more concentrated in organisms at the top of the food chain like orcas.

One of the major ways people are exposed to PCBs is through our diet, such as eating fish that contain PCBs. PCBs have been shown to have toxic effects to the immune, reproductive, nervous, and endocrine system in humans and other organisms. PCBs also cause cancer in animals, and are considered likely to cause cancer in humans.

Bioaccumulation of PCBs

Bioaccumulation of PCBs
(Image courtesy of Seattle Post Intelligencer)

PCBs were produced for commercial uses from about 1929 to 1977. The 1976 Toxic Substances Control Act bans certain uses and restricts PCB concentrations to low levels. The largest use of PCBs was for heat transfer fluids in electrical transformers and capacitors. PCBs were also used as plasticizers, wax and pesticide extenders, and lubricants. Many products used to contain PCBs at high levels, such as carbonless copy paper and caulk used to seal cracks in homes and buildings.

PCBs are still found in old products produced before commercial production of PCBs ended, such as in electrical transformers. They can also be found in new products either as a contaminant or intentionally added below regulated levels. There is still inadvertent production of PCBs during manufacturing of chemicals such as dyes and pigments.

PCB Chemical Action Plan

In 2015, the Washington departments of Ecology and Health released a chemical action plan to guide our state's strategy to find and remove PCBs, and reduce exposure to this toxic chemical. Although a great deal of work has already been done to reduce PCBs, this plan identifies important gaps that need to be filled in order to protect people and the environment. Ecology worked with stakeholders to identify these gaps and prioritize measures to reduce the risk posed by this toxic chemical in Washington.

The departments of Ecology and Health will continue their existing programs, such as cleanup, permitting, stormwater management, and fish advisories. The following recommendations are for new actions to reduce PCBs:

  • Identify PCB-containing lamp ballasts in schools and other public buildings. Encourage replacement with more energy-efficient PCB-free fixtures.
  • Develop and promote best management practices to contain PCBs in building materials, both in structures currently in use and those slated for remodel or demolition.
  • Assess schools and other public buildings for the presence of PCB-containing building materials.
  • Learn more about what products contain PCBs and promote the use of processes that don't inadvertently generate PCBs. Start with an alternatives assessment for pigments and dyes.
  • Expand environmental monitoring to identify new areas requiring cleanup and investigate air deposition.
  • Conduct a public education campaign.
  • Conduct a study on PCBs in Washington residents to prioritize future actions.

Read a summary of the report, or read the full PCB Chemical Action Plan.