Michael Hart, losakhamuti sase San Diego, wabekwa licala lekuphula imitsetfo yahulumende wase US lehlose kuvimbela kusetjentiswa kwamagesi lasho kutsi kubandza. Akusiko kwemtsetfo kungenisa ema hydrofluorocarbons (ema HFC) ngaphandle kwemvumo lekhetsekile lekhishwe yi Environmental Protection Agency (EPA).