The need to find alternatives to the CFCs and HCFCs used in today’s heating, air-conditioning and refrigeration equipment has led to intensified interest in the safety aspects of working fluids. Many of the environmentally acceptable alternatives are toxic or flammable (or both).

Annex 20 carried out an international study (entitled Working Fluid Safety) in five countries. This objective and scientific study provided a valuable insight into the risks associated with using refrigerants. The results play an important role in determining the choice of working fluid for tomorrow’s equipment, and in the precautions needed to achieve an acceptable risk.

Project manager and participating countries

The project manager (the so-called Operating Agent) was the “Katholieke Universiteit Leuven, Instituut Mechanica”, on behalf of Belgium.The following countries participated in this project: Belgium, Japan, the Netherlands, Norway, and Switzerland.


  • Working Fluid Safety

    This final report of this project examines the potential hazards of using natural refrigerants such as propane and ammonia, as well as synthetic substances such as HFCs.