TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The heat transfer device comprises a compressor. The device previously contains an existing refrigerant prior to containing the composition having a volumetric refrigeration capacity of within 15%, preferably 10% of the existing refrigerant, a cycle efficiency of within 5% of the existing refrigerant, a compressor discharge temperature of within 15K, preferably 10K of the existing refrigerant.    TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The composition further comprises at least one of pentafluoroethane (R-125) and R-134a, a lubricant, a stabilizer, and a flame retardant. The composition: comprises at least 45 wt.% of trans-1,3,3,3-tetrafluoropropene, 0-12 wt.%, preferably 2-10 wt.% of carbon dioxide, and 0-50 wt.%, preferably 3-6 wt.% of the third component; and has a global warming potential of less than 150 and a temperature glide of less than 10K, preferably less than 8K. The composition is less flammable than at least one of difluoromethane (R-32) alone, 1,1-difluoroethane (R-152a) alone, and 2,3,3,3-tetrafluoropropene (R-1234yf) alone (preferred). The composition has at least one of: (a) a higher flammable limit; (b) a higher ignition energy; and (c) a lower flame velocity as compared to at least one of R-32 alone, R-152a alone and R-1234yf alone (preferred). The composition has a fluorine ratio (F/(F+H)) of 0.42-0.67, preferably 0.46-0.65. Preferred Components: The lubricant comprises mineral oil, polyalkyl benzenes (both preferred), silicone oil, polyol esters, polyalkylene glycols, polyalkylene glycol esters, polyvinyl ethers, and/or poly (alpha-olefins). The stabilizer comprises diene-based compounds, phosphates, phenol compounds and/or epoxides. The flame retardant comprises tri-(2-chloroethyl)-phosphate, (chloropropyl) phosphate, tri-(2,3-dibromopropyl)-phosphate, tri-(1,3-dichloropropyl)-phosphate, diammonium phosphate, various halogenated aromatic compounds, antimony oxide, aluminum trihydrate, polyvinyl chloride, a fluorinated iodocarbon, a fluorinated bromocarbon, trifluoro iodomethane, perfluoroalkyl amines, and/or bromo-fluoroalkyl amines. The components capable of forming foam comprise polystyrene. Preferred Method: The method-8 further comprises: introducing the composition consisting of R-125, a lubricant, a stabilizer and a flame retardant into the heat transfer device; and removing at least some of the R-134a from the heat transfer device before introducing step. The method-9 further comprises use of the composition that results in a lower total equivalent warming impact, and/or a lower life-cycle carbon production than is attained by an at least substantially similar use of the existing compound or composition. The replacing step is carried out on a product from a field consisting of air-conditioning, refrigeration, heat transfer, blowing agents, aerosols or sprayable propellants, gaseous dielectrics, cryosurgery, veterinary procedures, dental procedures, fire extinguishing, flame suppression, solvents, cleaners, air horns, pellet guns, topical anesthetics, and expansion applications. EXAMPLE - No suitable example given.