HFC-containing Propellants in Canned PU Foam (OCF)

Januar 2009
Study for the German Umweltbundesamt (German Federal Environmental Agency) Project-no. 363 01 196
Winfried Schwarz

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.

As examined within this study, this is not required by any technical standards either including the following sectors:

  • Road construction
  • Tunneling
  • Ship building
  • Lines for supply and discharge of water, gas and power supply lines
  • District heating pipelines
  • Automotive industry (refrigerated trucks)

While fire protection standards apply to cured foam, explosion protection requires measures against flammable gases which are released from the can during the application process. The German labour protection laws set regulations for the handling of explosible hazardous substances but do not ban them. These laws are considered to set adequate safety standards for the use of OCF containing flammable hydrocarbon gases.

The underground coal mining sector is the only exemption. Due to the high explosion risk in this sector, the use of substances featuring a flashpoint < 55°C (flammable) is interdicted by law. The authorised OCF contain exclusively incombustible propellant gas, i.e. pure HFC-134a. The number of cans used in coal mining amounts to approximately 10,000 per year.

The ban of flammable gases in the coal mining industry is the only "national safety standard" which requires the use of OCF containing propellant gases which show a GWP >150 according to annex II of the EU F-Gas Regulation.

In case of a national update of the EU F-Gas Regulation, we suggest to continue to allow the use of OCF containing HFC-134a in the coal mining sector (hard coal mining).

A conflict situation will arise from mid-2009 onwards when new labelling obligations will ban the sale of isocyanate-containing OCF in self-service stores. Isocyanate-free OCF must not be sold either because they are not produced without HFC-134a so far. The manufacturers are developing isocyanate-free and HFC-free products (GWP < 150) and might be able to place them on the market in the near future.

In an additional chapter (annex), a new approach to estimate HFC emissions will be presented. Estimations for HFC emissions are given for the years 2006 to 2008 as well as emission prognoses for the years 2010 and 2020.

In Germany, climate-relevant emissions resulting from the application of OCF were cut from 1.5 million to 20,000 t CO2 equivalents in the period from 1998 to 2008. They are expected to decrease to 2,000 t by 2020.