It was discovered that tainted cooking oil was being produced by a Kaohsiung-based company Chang Guann Co. (強冠企業) and branded as Chuan Tung Fragrant Lard Oil (全統香豬油). The company was found to have blended cooking oil with recycled oil, grease and leather cleaner. The recycled oil was made by an unlicensed factory in Pingtung County owned by Kuo Lieh-cheng (郭烈成), who allegedly purchased the oil from waste recycler Hu Hsin-te (胡信德) whose factory is named Shun Te Enterprise (順德企業行) located in Daliao District of Kaohsiung. Chang Guann purchased up to 243 tonnes of recycled waste oil disguised as lard from the Pingtung factory since February 2014. The company then allegedly refined the waste oil before mixing it with processed lard and selling the tainted product to its distributors. The recycled waste oil was collected from restaurants as well as discarded animal parts, fat and skin.
The Taiwan Food Good Manufacturing Practice Development Association (TFGMPDA) said the cooking oil produced by Chang Guann has never acquired GMP certification, although the TFGMPDA said in an apology that five food companies whose products have won GMP certification have used the tainted oil.