169
Trifuoroacetic Acid from CFC Replacements
above the concentration that is expected to cause harm to the most sensitive
algae (120,000 ng/L) (Berends et al., 1999) although this was a grab sample
from the effuent of an industrial wastewater treatment plant. However, TFA
concentrations near fuorochemical facilities routinely range from 1,000 to
10,000 ng/L, which are concentrations that start to become worrisome from
a toxicology perspective since it leaves less of a safety margin before toxic
effects could be reached. TFA also arises from wastewater treatment facilities
serving residential populations, but the concentrations are much lower and
the suspected source might be from pharmaceuticals and domestic fuorochemical use (Scheurer et al., 2017). Other point sources of TFA include landflls (Bjornsdotter et al., 2019; Tian et al., 2018) and frefghting training sites
where fuorinated surfactants, such as aqueous flm-forming foams (AFFF),
were utilized (Bjornsdotter et al., 2019).
9.6 Conclusions
TFA is a ubiquitous halogenated acid that is very stable and likely to persist in the environment for considerable time. It is almost exclusively found
in the ionic form in the environment which makes it highly water soluble
and nonvolatile. In many ways, it behaves in a similar fashion as other small
ions such as chloride or bromide ions. These characteristics of the chemical
predispose it to partition into water and stay in the aqueous system. Unlike
the larger perfuorinated acids (e.g., PFOS and PFOA), it does not bioaccumulate in animals and it has relatively low toxicity. Its main toxicity appears
to be toward plants; terrestrial plants can bioaccumulate TFA in their above
ground biomass. The fate of most of the TFA generated is to be washed out
of the atmosphere and fow to the ocean in rivers and streams where it will
join a large pool of natural TFA whose source is still not completely clear.
The main concern regarding TFA is in water systems in arid areas that lack a
water outfow, so the TFA may accumulate over years to reach toxic concentrations. While current concentrations are still below toxic concentrations,
they need to be monitored to ensure that environmental impacts do not
develop. If negative impacts develop in these ecosystems, then the impacts
are expected to last for a very long time due to the stability of TFA.
References
Andersen, M.P.S., Nielsen, O.J., Karpichev, B., Wallington, T.J., and Sander, S.P. (2012).
Atmospheric chemistry of Isofurane, Desfurane, and Sevofurane: Kinetics
Trifuoroacetic Acid from CFC Replacements
above the concentration that is expected to cause harm to the most sensitive
algae (120,000 ng/L) (Berends et al., 1999) although this was a grab sample
from the effuent of an industrial wastewater treatment plant. However, TFA
concentrations near fuorochemical facilities routinely range from 1,000 to
10,000 ng/L, which are concentrations that start to become worrisome from
a toxicology perspective since it leaves less of a safety margin before toxic
effects could be reached. TFA also arises from wastewater treatment facilities
serving residential populations, but the concentrations are much lower and
the suspected source might be from pharmaceuticals and domestic fuorochemical use (Scheurer et al., 2017). Other point sources of TFA include landflls (Bjornsdotter et al., 2019; Tian et al., 2018) and frefghting training sites
where fuorinated surfactants, such as aqueous flm-forming foams (AFFF),
were utilized (Bjornsdotter et al., 2019).
9.6 Conclusions
TFA is a ubiquitous halogenated acid that is very stable and likely to persist in the environment for considerable time. It is almost exclusively found
in the ionic form in the environment which makes it highly water soluble
and nonvolatile. In many ways, it behaves in a similar fashion as other small
ions such as chloride or bromide ions. These characteristics of the chemical
predispose it to partition into water and stay in the aqueous system. Unlike
the larger perfuorinated acids (e.g., PFOS and PFOA), it does not bioaccumulate in animals and it has relatively low toxicity. Its main toxicity appears
to be toward plants; terrestrial plants can bioaccumulate TFA in their above
ground biomass. The fate of most of the TFA generated is to be washed out
of the atmosphere and fow to the ocean in rivers and streams where it will
join a large pool of natural TFA whose source is still not completely clear.
The main concern regarding TFA is in water systems in arid areas that lack a
water outfow, so the TFA may accumulate over years to reach toxic concentrations. While current concentrations are still below toxic concentrations,
they need to be monitored to ensure that environmental impacts do not
develop. If negative impacts develop in these ecosystems, then the impacts
are expected to last for a very long time due to the stability of TFA.
References
Andersen, M.P.S., Nielsen, O.J., Karpichev, B., Wallington, T.J., and Sander, S.P. (2012).
Atmospheric chemistry of Isofurane, Desfurane, and Sevofurane: Kinetics