New environmentally friendly hybrid surfactants for fire fighting
foams

Silvia Luebben, TDA Research, Inc.

Aqueous film-forming foams (AFFFs) are among the most popular
firefighting foams used against fuel and oil fires in both military and
civil environments because of their effectiveness and their ease of
application.  Unfortunately, recent studies have shown that one key
ingredient of AFFFs, the fluorosurfactant perfluorooctyl sulfonate
(PFOS), is toxic to aquatic life and is a persistent chemical that
accumulates in the blood of animals and humans.  Thus, the production of
PFOSs was stopped in May 2000.  Among the phase out products are 44
AFFFs and firefighting foam components.   The fire-fighting industry is
stocked with materials that have been phased out and that, sooner or
later, need to be replaced.  Many of the foam concentrates sold today
still contain fluorinated surfactants, but they are chemically different
from those that have been phased out.  Their toxicity and persistency in
the environment are unknown and still are under investigation, and their
presence in the future market is unsure.  Therefore, the fire fighting
industry has an urgent need for new environmentally friendly foaming
agents and foam stabilizers that will replace the phased-out
fluorosurfactants.  

The objective of this Phase I EPA-sponsored SBIR project was to
investigate the surface-active properties of TDA's proprietary additives
in water, and evaluate their use as components of fire fighting foam
concentrates. TDA's additives form very stable aqueous foams upon mixing
with water and air.

During the project TDA Research, Inc. developed novel fluorine-free foam
stabilizers for fire-fighting foam concentrates.  TDA demonstrated that
these foam stabilizers are compatible with current fire-fighting
equipment and can be used to suppress fuel fires (class B fires).  TDA
also identified new surfactant types that, in combination with TDA's
foam stabilizers, offer the potential to develop an environmentally
friendly AFFF replacement product.

TDA's additives will find immediate application in foam concentrates for
fire fighting.  Once their properties are established, TDA's additives
could be used in many industries including waste management,
construction, paper, textile, detergent, coating and personal care.