<Table> <Tr> <Th_colspan="4"> hide Principal CFCs </Th> </Tr> <Tr> <Th> Systematic name </Th> <Th> Common / trivial name (s), code </Th> <Th> Boiling point (° C) </Th> <Th> Formula </Th> </Tr> <Tr> <Td> Trichlorofluoromethane </Td> <Td> Freon - 11, R - 11, CFC - 11 </Td> <Td> 23.77 </Td> <Td> CCl F </Td> </Tr> <Tr> <Td> Dichlorodifluoromethane </Td> <Td> Freon - 12, R - 12, CFC - 12 </Td> <Td> − 29.8 </Td> <Td> CCl F </Td> </Tr> <Tr> <Td> Difluoromethane / pentafluoroethane </Td> <Td> R - 410A, Puron, AZ - 20 </Td> <Td> − 48.5 </Td> <Td> 50% CH F / 50% CHF CF </Td> </Tr> <Tr> <Td> Chlorotrifluoromethane </Td> <Td> Freon - 13, R - 13, CFC - 13 </Td> <Td> − 81 </Td> <Td> CClF </Td> </Tr> <Tr> <Td> Chlorodifluoromethane </Td> <Td> R - 22, HCFC - 22 </Td> <Td> − 40.8 </Td> <Td> CHClF </Td> </Tr> <Tr> <Td> Dichlorofluoromethane </Td> <Td> R - 21, HCFC - 21 </Td> <Td> 8.9 </Td> <Td> CHCl F </Td> </Tr> <Tr> <Td> Chlorofluoromethane </Td> <Td> Freon 31, R - 31, HCFC - 31 </Td> <Td> − 9.1 </Td> <Td> CH ClF </Td> </Tr> <Tr> <Td> Bromochlorodifluoromethane </Td> <Td> BCF, Halon 1211, H - 1211, Freon 12B1 </Td> <Td> − 3.7 </Td> <Td> CBrClF </Td> </Tr> <Tr> <Td> 1, 1, 2 - Trichloro - 1, 2, 2 - trifluoroethane </Td> <Td> Freon 113, R - 113, CFC - 113, 1, 1, 2 - Trichlorotrifluoroethane </Td> <Td> 47.7 </Td> <Td> Cl FC - CClF </Td> </Tr> <Tr> <Td> 1, 1, 1 - Trichloro - 2, 2, 2 - trifluoroethane </Td> <Td> Freon 113a, R - 113a, CFC - 113a </Td> <Td> 45.9 </Td> <Td> Cl C - CF </Td> </Tr> <Tr> <Td> 1, 2 - Dichloro - 1, 1, 2, 2 - tetrafluoroethane </Td> <Td> Freon 114, R - 114, CFC - 114, Dichlorotetrafluoroethane </Td> <Td> 3.8 </Td> <Td> ClF C - CClF </Td> </Tr> <Tr> <Td> 1 - Chloro - 1, 1, 2, 2, 2 - pentafluoroethane </Td> <Td> Freon 115, R - 115, CFC - 115, Chloropentafluoroethane </Td> <Td> − 38 </Td> <Td> ClF C - CF </Td> </Tr> <Tr> <Td> 2 - Chloro - 1, 1, 1, 2 - tetrafluoroethane </Td> <Td> R - 124, HCFC - 124 </Td> <Td> − 12 </Td> <Td> CHFClCF </Td> </Tr> <Tr> <Td> 1, 1 - Dichloro - 1 - fluoroethane </Td> <Td> R - 141b, HCFC - 141b </Td> <Td> 32 </Td> <Td> Cl FC - CH </Td> </Tr> <Tr> <Td> 1 - Chloro - 1, 1 - difluoroethane </Td> <Td> R - 142b, HCFC - 142b </Td> <Td> − 9.2 </Td> <Td> ClF C - CH </Td> </Tr> <Tr> <Td> Tetrachloro - 1, 2 - difluoroethane </Td> <Td> Freon 112, R - 112, CFC - 112 </Td> <Td> 91.5 </Td> <Td> CCl FCCl F </Td> </Tr> <Tr> <Td> Tetrachloro - 1, 1 - difluoroethane </Td> <Td> Freon 112a, R - 112a, CFC - 112a </Td> <Td> 91.5 </Td> <Td> CClF CCl </Td> </Tr> <Tr> <Td> 1, 1, 2 - Trichlorotrifluoroethane </Td> <Td> Freon 113, R - 113, CFC - 113 </Td> <Td> 48 </Td> <Td> CCl FCClF </Td> </Tr> <Tr> <Td> 1 - bromo - 2 - chloro - 1, 1, 2 - trifluoroethane </Td> <Td> Halon 2311a </Td> <Td> 51.7 </Td> <Td> CHClFCBrF </Td> </Tr> <Tr> <Td> 2 - bromo - 2 - chloro - 1, 1, 1 - trifluoroethane </Td> <Td> Halon 2311 </Td> <Td> 50.2 </Td> <Td> CF CHBrCl </Td> </Tr> <Tr> <Td> 1, 1 - Dichloro - 2, 2, 3, 3, 3 - pentafluoropropane </Td> <Td> R - 225ca, HCFC - 225ca </Td> <Td> 51 </Td> <Td> CF CF CHCl </Td> </Tr> <Tr> <Td> 1, 3 - Dichloro - 1, 2, 2, 3, 3 - pentafluoropropane </Td> <Td> R - 225cb, HCFC - 225cb </Td> <Td> 56 </Td> <Td> CClF CF CHClF </Td> </Tr> </Table> <Tr> <Th_colspan="4"> hide Principal CFCs </Th> </Tr> <Tr> <Th> Systematic name </Th> <Th> Common / trivial name (s), code </Th> <Th> Boiling point (° C) </Th> <Th> Formula </Th> </Tr> <Tr> <Td> Trichlorofluoromethane </Td> <Td> Freon - 11, R - 11, CFC - 11 </Td> <Td> 23.77 </Td> <Td> CCl F </Td> </Tr>

Chlorofluorocarbons or cfcs are the main cause of