An R-J Reynolds cigarette designer testified his company used freon (FREE'-on) to process tobacco without conducting long-term research on the chemical's effect on health. Freon is a toxic refrigerant that when burned can form the nerve gas, phosgene (FOZZ'-jeen). Freon was banned because it's also linked to destroying the ozone layer. Minnesota Public Radio's Elizabeth Stawicki reports: Vice President David Townsend said Reynolds used freon in processing tobacco for 23 years--from 1970 to 1993. Townsend said his company used the chemical to expand tobacco for low-tar cigarettes. Expanded tobacco meant less leaf was needed to fill cigarettes. He said he was unaware if the company knew freon residue could harm smokers because reynolds never conducted long-term health studies. Another tobacco company apparently did.