An otherwise normal-looking drinks can is provided with a false bottom that contains a refrigerant, usually an HFC (hydrofluorocarbon). By pressing a button on the bottom, the can and contents are quickly cooled. The device is an American invention (the term Chill Can is a trademark of the Joseph Company Inc of California), designed to produce cool drinks in places where refrigerators are not readily available. Though it seems a useful little device, it has been widely criticised because of the environmental consequences of releasing HFCs into the atmosphere. Unlike CFCs (chlorofluorocarbons), which are now banned in most developed countries, the HFCs don’t have much impact on the ozone layer, but they are even more effective greenhouse gases, and so contribute to global warming. Several major suppliers of HFCs, including ICI in Britain, have now publicly refused to supply them to drinks manufacturers for this purpose, and the British government is pressing the European Union to ban them altogether, so the Chill Can may struggle to be accepted, unless its manufacturers can find some less environmentally sensitive working fluid.