The propellant gases of OCF – first CFCs, then HCFCs, finally HFCs – have been subject to environmental legislation. In1998, the application of OCF still constituted the major source of HFC emissions at that time by causing global warming emissions of 1.5 million t ⁠CO2⁠ equivalents in Germany.The study shows that a lot of time was required before the European manufacturers were able to produce canned PU foam without HFC containing propellants but within the German fire protection standards for buildings. All of the eight manufacturers featuring the market in Germany can offer HFC-free OCF of commercially available type classified into Building Material Class B2. In Germany, no legal regulations require the use of materials classified less flammable than Building Material Class B2 which would apply to materials classified into Building Material Class B1 only.