Chlorofluorocarbons (CFC) are gases used in refrigerants and aerosols. They contain carbon, (sometimes hydrogen,) chlorine, and fluorine. In 1978, Sweden became the first country that banned CFC products. Later, the US and Canada did the same. Now, CFC products are not allowed in most countries, because they destroy the ozone layer. CFCs also are greenhouse gases, creating a natural-made greenhouse effect. An alternative is hydrofluorocarbons (HFCs). These do not destroy the ozone layer or increase global warming.