After 1904, instead of using fresh leaves, Coca-Cola started using "spent" leaves – the leftovers of the cocaine-extraction process with trace levels of cocaine.[73] Since then (by 1929 [74]), Coca-Cola has used a cocaine-free coca leaf extract. Today, that extract is prepared at a Stepan Company plant in Maywood, New Jersey, the only manufacturing plant authorized by the federal government to import and process coca leaves, which it obtains from Peru and Bolivia.[75] Stepan Company extracts cocaine from the coca leaves, which it then sells to Mallinckrodt, the only company in the United States licensed to purify cocaine for medicinal use.[76]