chlorofluorocarbons

The acronym internationally used for chlorofluorocarbons. These synthetic chemical compounds, of industrial origin and also known as freons, began to be used in the 1930s as refrigerants, being incorporated into refrigerator circuits to replace toxic, corrosive ammonia. From the 1960s onward, they began to be used massively as aerosol propellants (lacquers, paints...) and as solvents in cleaning products, given their apparent lack of toxicity and flammability, as well as their seemingly low chemical reactivity. Alarm bells rang in the mid-1970s, when the chemists F. Sherwood Rowland and Mario Molina discovered that, due to their prolonged residence in the atmosphere, these gases destroyed stratospheric ozone molecules, contributing to the decrease in the concentration of that gas over Antarctica. Following the entry into force of the Montreal Protocol - on January 1, 1989 -, their manufacture was banned, being progressively replaced by other, more harmless chemical compounds.