Freon
Freon yog ib qho kev piav qhia dav dav rau ntau cov khoom lag luam halocarbon. Lawv yog cov ruaj khov, nonflammable, tsis tshua muaj toxicity gases los yog kua uas feem ntau tau siv los ua cov tub yees thiab ua aerosol propellants. Cov no suav nrog chlorofluorocarbons thiab hydro fluorocarbons, ob qho tib si ua rau ozone depletion (txawm tias tom kawg tsawg dua li) thiab ua rau lub ntiaj teb sov.
Keeb kwm
Thawj CFCs tau tsim los ntawm Frederic Swartz hauv xyoo 1890. Thaum xyoo 1920s lig, ib pab neeg tshawb fawb tau tsim los ntawm Charles Franklin Kettering hauv General Motors los nrhiav kev hloov pauv rau cov tub yees txaus ntshai thaum siv, xws li ammonia. Pab neeg no tau coj los ntawm Thomas Medley, Jr. Hauv xyoo 1928, lawv tau txhim kho cov kev sib txuas ntawm CFCs thiab pom tias lawv muaj txiaj ntsig zoo rau lub hom phiaj no thiab lawv qhov ruaj khov thiab tsis muaj tshuaj lom. Kettering patented lub tub yees apparatus siv cov roj; Qhov no tau muab rau Frigidaire, uas yog tus tswv lag luam tag nrho ntawm General Motors.
Xyoo 1930, General Motors thiab DuPont tsim Kinetic Chemicals los tsim Freon. Lawv cov khoom yog dichlorodifluoromethane thiab tam sim no raug xaiv "Freon-12", "R-12", lossis "CFC-12". Tus lej tom qab R yog tus naj npawb ntawm cov tub yees uas tsim los ntawm DuPont los txheeb xyuas ib leeg halogenated hydrocarbons, nrog rau lwm cov refrigerants ntxiv rau halocarbons.
