Sediment Phthalates Work Group

What are "phthalates"?

Phthalates (“thal-ates”) are pollutants found in our air, soil, and water. Phthalates are plasticizers used widely in consumer products such as cosmetics, vinyl flooring, children’s toys, flexible plastics, lubricants, and adhesives. Each chemical has different characteristics and potential effects.

Why are we concerned about phthalates in sediments?

We have several concerns about phthalates. For example:

  • Sediments in urban areas of Puget Sound frequently contain phthalates above the Washington Department of Ecology cleanup levels, which are set to protect aquatic organisms.
  • Research shows phthalates wind up in marine sediments and can cause harm to organisms that live there.
  • Phthalates are pervasive in the environment because they are contained in hundreds of common products found in everyday life.
  • Phthalates enter waters through many ways, so identifying precise sources of contamination is difficult.
  • We know little about how to control or treat phthalate contamination.

What's being done?

The cities of Tacoma and Seattle, King County, Washington Department of Ecology, and U.S. Environmental Protection Agency have worked together to better understand how phthalates are reaching Puget Sound sediments and what are the related impacts to humans and animals. A work group was voluntarily created with representatives from each public agency. The work group recognized the challenges that municipal governments face regarding phthalates in sediments at important cleanup sites such as the Thea Foss Waterway and Lower Duwamish River. The group also studied the occurrence of phthalates in other areas of Puget Sound.

Work group goals

The work group evaluated existing information regarding phthalate sediment concentrations, identified data gaps, and recommended possible short-term actions. They also described possible ways to address long-term issues such as:

  • Defining phthalate concerns within current regulations.
  • Placing sediment phthalate concerns in perspective with other sediment contamination risks and within the broader issue of phthalate risks from all exposure pathways.
  • Documenting where phthalates occur and identify potential sources.
  • Identifying source control and treatment options.
  • Examining data collected by work group members and providing recommendations on next steps.
  • Sharing findings with the public.

Information sharing and outreach

The work group developed public messages and recommendations using a collaborative approach in which ideas were shared openly. During 2007, the work group presented draft recommendations to stakeholders for review and comment. Work group members also used existing community and stakeholder forums to discuss the group’s process and receive feedback.

Work group recommendations

In September 2007, the work group made recommendations to address phthalate sediment contamination for regulatory agencies and the community to consider.