1,1,2,2-Tetrachloro-1-fluoroethane 1-Fluoro-1,1,2,2-tetrachloroethane 134237-32-4 354-14-3 EINECS 206-546-8 ETHANE, 1,1,2,2-TETRACHLORO-1-FLUORO- F 121 Fluorotetrachloroethane Freon 121 HCFC-121 HSDB 6975