Global Evaluations—HF Formation
Four years of global testing also concluded that the use of HFO-1234yf presents little risk of the formation of hydrogen fluoride (HF). HF is a decomposition product that in certain circumstances can be formed when fluorinated refrigerants hit an extremely hot surface or pass through a flame. It should be understood that HF can also be formed as a product of R-134a under the same circumstances. There have been no documented cases of exposure to HF during the 15 years R-134a has been used as an automotive refrigerant. To date, there are no known published medical reports of any documented injuries attributed to HF formed through accidental release of R-134a.
All the publically available industry-wide assessments have concluded that HFO-1234yf can be used safely and that neither flammability nor HF formation present a significant safety concern.