Oil Spill Dispersants

Chemical oil spill dispersants are substances applied to spilled oil in order to disperse the oil into the water column rather than leaving it floating on the surface in a slick. The Council has long endorsed mechanical recovery as the primary tool to combat an oil spill. Unlike dispersant use, mechanical recovery with booms and skimmers removes oil from the water.

Current state and federal laws and regulations hold that dispersants should be used only if it is clear that mechanical cleanup methods such as booming and skimming won’t work.

Council’s Position on Oil Spill Dispersants

In 2006, after years of promoting research and testing to increase knowledge about dispersants and the environmental consequences of their use, the Council adopted a position against the use of dispersants in the Exxon Valdez oil spill region:

After years of observing dispersant trials, dispersant effectiveness monitoring, advising and sponsoring independent research regarding chemical dispersant use, it is the position of the Prince William Sound Regional Citizens’ Advisory Council that dispersants should not be used on Alaska North Slope crude oil spills in the waters of our region.

Until such time as chemical dispersant effectiveness is demonstrated in our region and shown to minimize adverse effects on the environment, the Council does not support dispersant use as an oil spill response option.

Mechanical recovery and containment of crude oil spilled at sea should remain the primary methodology employed in our region.

A 2013 document supplemented that position.

Among the Council’s concerns is the scarcity of reliable scientific data about the efficacy, toxicity, and persistence of dispersants and dispersed oil in Prince William Sound/Gulf of Alaska conditions. There has not been a conclusive demonstration that chemical dispersants work in the extremely cold waters of Prince William Sound. Although effort has been put into evaluating chemical dispersant use over the last 30 years, a good portion of this effort was conducted by the formulators of dispersants and not by independently funded surfactant scientists.

The Council seriously questions dispersant use based upon photoenhanced toxicity concerns and other outstanding questions regarding long-term effects. Photoenhanced toxicity occurs when a chemical becomes more toxic if exposed to the ultraviolet light present in natural sunlight.

Position on Dispersants:

Dispersant Use Position Statement (28 KB)

Dispersant Position Paper (43 KB)

A summary of scientific counter observations from our decades of research:

Why PWSRCAC Does Not Support The Use Of Chemical Dispersants - November 2013 (84 KB)

For more information, read the Council’s public comments on the proposed changes from 2013, and a series of documents explaining the issues: Public comments on guidelines for use of dispersants in Alaska

More on dispersants:

Regulations and Guidelines for Oil Spill Dispersants in Alaska

Alaska Regional Response Team – The ARRT is an advisory board to the federal and state on-scene coordinators. It provides federal, state, and local governmental agencies with means to participate in response to pollution incidents. The ARRT also provides the guidance document for the use of dispersants in Alaska.

Dispersant Use Guidelines for Alaska (PDF on ADEC website) – Spill responders must use these guidelines when considering the use of dispersants. The council closely follows changes to these guidelines and provides input to the ARRT during public comment periods.


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