Anionic surfactants are a group of specialty chemicals used in
detergents. One particular class of surfactants, fluorinated
surfactants, has unique properties that make the compounds
especially effective in fire-fighting. First developed in the 1960s
by the US Naval Research Laboratory, they produce a thin aqueous
film which spreads across the surface of the fuel, starving it of
oxygen. Known as aqueous film-forming foam (AFFF), it is used for
hydrocarbon fuel fires in many parts of the world.
Unfortunately, fluorinated surfactants are also toxic, persistent
and bio-accumulate, and are now globally distributed.
Over the past three years, researchers from CRC CARE have been
investigating the environmental toxicity and persistence of AFFF,
and the new alternative products now available, to help with the
management and cleanup of contaminated sites. The findings of this
work were presented at an AFFF workshop in Adelaide in June to
consultants, land owners and regulators.
New knowledge presented included the chemical and physical
properties of AFFF and its toxicity in aquatic and terrestrial
environments.
Presentations by CRC CARE staff were also supported by case study
examples. Brooke Moore from ENSR USA provided an overview of what
triggered investigation into AFFF toxicity in the US, and outlined
current policy developments in US regulatory authorities.
As part of discussions, participants reviewed the limitation of
having no existing Ecological Investigation Levels (EILs) and
Health Investigation Levels (HILs) for AFFF in Australia. It
is expected that CRC CARE will take up this challenge and work with
our partners towards the development of Australian based EILs and
HILs for AFFF that are underpinned by scientific investigation.
The AFFF field test kit developed by CRC CARE was demonstrated at
the workshop. Designed for field use in establishing the level of
contamination of sites where AFFF compounds have long been in use,
the kit will replace time-consuming and expensive laboratory
procedures. It is believed to have commercial potential around the
world as environmental agencies come to grips with the extent of
contamination caused by the foams.
Future work by CRC CARE will continue research on the remediation
of AFFF constituents, as well as pursue commercialisation of the
new kit.
