chemicals used as refrigerants and cooling agents in the industries of manufacture and maintenance of heating, ventilating, refrigerating and cooling, and air conditioning equipment; chemicals used as solvents in chemical manufacturing industry [ and in the manufacture of electrical and electronic components ] ; chemicals used in industry as aerosol propellants in the manufacture of spray packaged components; chemicals used in industry as blowing agents for use in the manufacture of foamed plastics materials; [ chemicals used in the manufacture of fire extinguishing compositions for incorporation into hand held fire extinguishers and industrial flame smothering applications; ] non-flammable volatile organic chemical liquids for use as heat transfer mediums