1,1,2,2-Tetrachloro-1-fluoroethane (HCFC-121)

HCFC-121 is a man-made hydrochlorofluorocarbon once used as a refrigerant/solvent and as a chemical intermediate. It is toxic at high levels and depletes the ozone layer, so production and use are being phased out in many countries [1]. Breathing high concentrations can affect the brain and heart [2].

Where It Comes From

Legacy refrigeration/cleaning uses, chemical manufacturing, and releases during equipment servicing or disposal [1][3].

How You Are Exposed

Mainly by inhaling vapors at work; less often from leaks near stored cylinders, spills, or old equipment [1][2].

Why It Matters

Short-term exposure can cause dizziness, headache, and nausea; very high levels may trigger irregular heartbeat or fainting. Liquid contact can cause frostbite. It also depletes ozone and is a greenhouse gas [2][1].

Who Is at Risk

Workers who make, transfer, or service refrigerants; people in poorly ventilated spaces; those with heart disease or using stimulants may be more sensitive to heart effects [2].

How to Lower Your Exposure

Use trained technicians; prevent and fix leaks; ventilate work areas; follow EPA refrigerant rules; wear appropriate gloves/eye protection; replace obsolete HCFCs with safer alternatives [1][2].

References

[1]U.S. EPA. HCFCs and the Phaseout of Ozone-Depleting Substances. https://www.epa.gov/ods-phaseout/hcfc-phaseout
[2]NOAA CAMEO Chemicals. 1,1,2,2-Tetrachloro-1-fluoroethane (CAS 354-14-3). https://cameochemicals.noaa.gov/
[3]NIH PubChem. 1,1,2,2-Tetrachloro-1-fluoroethane. https://pubchem.ncbi.nlm.nih.gov/compound/354-14-3