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refrigerant
A substance used in a thermodynamic heat pump cycle or refrigeration cycle that undergoes a phase change from a gas to a liquid and back. Refrigerants are used in air-conditioning systems and freezers or refrigerators and are assigned a "R" number (by ASHRAE - formerly the American Society of Heating, Refrigerating and Air Conditioning Engineers), which is determined systematically according to their molecular structure.
polar aprotic solvent
A solvent with a comparatively high relative permittivity (or dielectric constant), greater than ca. 15, and a sizable permanent dipole moment, that cannot donate suitably labile hydrogen atoms to form strong hydrogen bonds.
fumigant
A volatile or volatilizable chemical compound utilized for control of pests in buildings, soil, grain, as well as during processing of goods to be imported or exported to prevent transfer of exotic organisms.
insecticide
Strictly, a substance intended to kill members of the class Insecta. In common usage, any substance used for preventing, destroying, repelling or controlling insects.
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