The third assessment report of the intergovernmental panel on climate change
Sept. 2012
Preamble : Readers should be aware that the abbreviation PFCs is being used for two different classes of classes of products.
PFCs (perfluorocarbons), covered by the Kyoto Protocol, are organofluorine compounds that contain exclusively carbon and fluorine. Examples are CF4 (tetrafluoroethane) and C2F6 (hexafluoroethane or perfluoroethane). These substances have high global warming potential but do not bioaccumulate and are considered to be of low order of toxicity. They are gases or volatile liquids.
While other compounds which contain atoms other than carbon and fluorine are also sometimes called PFCs, they should in effect be considered specifically as fluorocarbon derivatives. Examples are PFOA (perfluorooctanoic acid: C8HF15O2) and PFOS (perfluorooctanesulfonic acid : C8HF17O3S ). These are typically surfactants with long carbon chains, with uses in fluoropolymer preparations and for water repellancy.
The properties of these substances - bioaccumulation and stability - means that voluntary and regulatory measures are being taken to control their use and minimize their emissions to the environment.
As part of the accelerated EU phase-out of HCFC solvents use under European Regulation EC 2037(2000) the precision cleaning market is changing, with “not-in-kind” technologies taking over the main market share. “In-kind” solvents such like HFEs & HFCs are expected to reach a level of no more than 15% of the previous volume of HCFC solvents. This value of 15% was a typical conversion factor during the previous change of fluorine containing solvent from CFC-113 to HCFC-141b and the reduction comes from continuing technical advances in equipment.
When any piece of equipment reaches the end of its service life, it is good practice to attempt to recover all of the components for safe disposal or, better still, re-use. In the case of refrigeration equipment, the fluid in the system can be drained out and reprocessed to be used again. Recovery of the insulating gas in plastic foam insulation is more difficult but technically possible and, again, the gas may be re-used.