[ FLUOROCARBONS FOR USE IN MANUFACTURE OF POLYTETRAFLUOROETHYLENE ] POLYMERS, [ REFRIGERANTS AND ] BLOWING AGENTS FOR POLYURETHANE FOAMS, PVC FOAMS, POLYSTYRENE FOAMS AND IN FROTH-FOAMING OF URETHANE FOAMS; ALSO FOR USE IN AEROSOL PROPELLANTS, [ HEAT TRANSFER MEDIUMS, ] DRY CLEANING, LEAK DETECTION, SOLVENT EXTRACTION, BIOLOGICAL PROCESSES, AIR CONDITIONING AND VAPOR PRESSURE INSTRUMENTS