The new hydrofluorocarbons (HFCs) and hydrochlorofluorocarbons (HCFCs) replacements for the chlorofluorocarbons (CFCs) are largely degraded before reaching the stratosphere. The final breakdown products are various fluorinated and chlorinated acetic acids. Some of these are rapidly broken down by microbiological activity in water, soil, and sediments. Other breakdown products such as trifluoroacetic acid (TFA) are very persistent but they are very water soluble and chemically nonreactive.

Because of their properties, these breakdown products will ultimately collect in aquatic environments. They have low toxicity to aquatic organisms and are very unlikely to adversely affect human health or the environment.

HFCs and HCFCs (CF3CXYH) break down relatively rapidly to several products including the persistent substances such as trifluoroacetic acid (CF3COOH) and chlorodifluoroacetic acid (CF2ClCOOH).

These are washed from the atmosphere by precipitation and reach surface waters, along with other chemicals washed from the soil. In locations where there is little or no outflow and high evaporation (seasonal wetlands, salt lakes and playas), these products are expected to increase in concentration over time. The concentrations of trifluoroacetic acid and chlorodifluoroacetic acid are expected to increase. While this may present a risk to aquatic organisms, these areas would also experience increases in concentrations of other water-soluble materials such as has already occurred. The effects of increased concentrations of these naturally occurring salts and other materials would likely be greater and more biologically significant than those of breakdown products of the HFCs and HCFCs.

The results of this interaction with global climate change are judged to be of low significance, since the phytotoxicity of trifluoroacetic acid is not high.

Illustration of the formation of persistent, water-soluble breakdown products of the HFCs and HCFCs (CF3-CXYH) and their movement and concentration by evaporation, along with other water-soluble salts to surface waters.