The Office of Emergency Response (OER)
Media Fact Sheet for Oil Spill Dispersant Use
Dispersants are chemicals that are applied directly to an oil slick.
The key components of chemical dispersants are surface active agents
called surfactants (also known as detergents). Chemical dispersants assist
with breaking up the slick into small droplets ranging in size from a few
micrometers to a few millimeters.
Chemical dispersants can do this because they contain molecules that
are both water compatible and oil compatible. The molecules align
themselves around the oil droplets as the droplets break away from the
slick. This action prevents the coalescence (reforming or joining) of oil
droplets so the oil can no longer form a slick on the water surface, and
it reduces the adherence of the oil to solid particles (sand) and hard
surfaces (seawalls and boat hulls).
Chemical dispersants remove the oil from the surface of the water and
into the water column. Once in the water column, the oil is diluted to
less harmful levels, and eventually is used as a food by bacteria. By
removing the oil from the water surface, birds, marine mammals, turtles,
and Florida's sensitive coast is protected. Chemical dispersants do not
cause the oil to sink, but remain in suspension in the water column.
Not any chemical dispersant may be used. Only chemical dispersants that
are listed on the National Product Schedule (NCP) may be used to treat oil
spills. Manufactures who want to list their chemical dispersants on the
NCP must complete specific tests demonstrating effectiveness of at least
45%, aquatic toxicity, and identify ingredients. The results of these
tests are sent to the U.S. Environmental Protection Agency for evaluation.
Are chemical dispersants toxic? Yes, but the dispersants used today are
generally not as toxic as the oil itself, and with adequate dilution, will
not harm aquatic life. As an added precaution, chemical dispersants are
not applied to shallow nearshore waters, mangrove areas, marshes, or
waters over coral reefs and seagrass beds.
Name of Chemical Dispersant Used:
Method of Application:
Area to be Treated:
Date and Time of Application:
Florida Department of Environmental Protection
Bureau of Emergency Response (850)245-2010