Overview
A University of Bristol-led study suggests that a newer refrigerant, HFO-1234yf, used in car air conditioning systems, may be a significant source of a 'forever chemical' pollutant across Europe. The study indicates that trifluoroacetic acid (TFA), a type of per- and polyfluoroalkyl substance (PFAS), is increasing due to the widespread adoption of HFO-1234yf.
Research Context
HFO-1234yf was introduced as a replacement for the refrigerant HFC-134a in automotive air conditioning systems throughout Europe. This replacement was mandated to comply with EU F-gas regulations aimed at reducing the climate impact of refrigerants. While HFO-1234yf has a lower global warming potential than HFC-134a, its atmospheric degradation product is TFA. TFA is a persistent organic pollutant that does not break down in the environment, leading to its categorization as a 'forever chemical'. Previous research had projected increases in TFA concentrations due to HFO-1234yf use, but directly attributing current observed increases in European TFA levels to this specific refrigerant has been a focus for researchers.
Approach
The research involved atmospheric measurements taken at two European sites: Mace Head, Ireland, and Jungfraujoch, Switzerland. These sites are used for monitoring atmospheric composition. The atmospheric data collected included measurements of HFO-1234yf and TFA. The researchers combined these atmospheric measurements with emissions data, particularly focusing on the introduction and increasing use of HFO-1234yf in automotive applications in Europe.
Findings
- HFO-1234yf is widely detected across Europe, with increasing concentrations observed at monitoring stations.
- Emissions of HFO-1234yf result in the atmospheric formation of trifluoroacetic acid (TFA).
- The study found increasing concentrations of TFA across Europe.
- The increase in TFA is largely consistent with emissions of HFO-1234yf from automotive sectors, particularly since its widespread adoption.
- The observed increases suggest that HFO-1234yf is a significant, and potentially dominant, source of TFA pollution in Europe.
Why This Matters
The findings indicate an unintended consequence of regulatory efforts to address climate change. While HFO-1234yf was adopted for its lower global warming potential, its breakdown product, TFA, represents a persistent environmental pollutant. This highlights a potential trade-off between reducing climate impact and increasing 'forever chemical' pollution, as TFA accumulates in the environment and has unknown long-term ecological and health effects.
Research Source
University of Bristol