Gutter oil
It can also be used to describe the reprocessing of yellow grease collected from sources such as restaurant fryers, kitchen, slaughterhouse waste and sewer drains.
[6] In 2015, Yeh Wen-hsiang, who was the chairman of a Taiwanese food company, was sentenced to 22 years imprisonment and fined the equivalent of $1.6 million for selling 243 tonnes of gutter oil.
[10] Some street vendors and restaurants in China are reported to have illegally used recycled oil unfit for human consumption to cook food.
[16] As Feng Ping of the China Meat Research Center has said: "The illegal oil shows no difference in appearance and indicators after refining and purification, because the law breakers are skillful at coping with the established standards.
"[17] In September 2012, an ongoing investigation into the suspected use of gutter oil as a raw material in the Chinese pharmaceutical industry was revealed.
[18] A scandal involving 240 tons of gutter oil in Taiwan affecting hundreds of companies and thousands of eateries, some of which may have been exported overseas, broke in September 2014.
[19] In 2018, researchers worked on identifying different components in gutter oil using 1H NMR (proton nuclear magnetic resonance), MALDI-MS (matrix-assisted laser desorption/ionization-mass spectrometry) and HPLC (high-performance liquid chromatography).
[20] Chinese law states that industrial-grade animal fat is not allowed for use in food products because it does not meet basic hygiene standards and may contain high levels of potentially toxic contaminants.
[21] The national and local governments are researching ways to test and identify gutter oil but as of 2012[update] there were no nationwide standards in place to help with this process.
[22] Food safety articles funded by PRC provincial science grants attribute continued difficulties in regulatory enforcement to the decentralized nature of the logistics chain, inadequate national infrastructure for disposal/recycling, and frequent innovations in visually and chemically disguising gutter oil.
[27][28][29][30] In October 2013, a man from eastern China's Jiangsu Province was sentenced to life imprisonment for profiting heavily from making and selling gutter oil.
[5] Entire illicit supply chains dedicated to collecting, processing, and reselling gutter oil have been discovered by regulators in China.
Bleach is used to transform gutter oil's dark color into a more natural-looking one, and alkali additives are used to neutralize the abnormal pH caused by high concentrations of animal fats.
Yellow and brown grease typical of gutter oil are acceptable raw feedstocks for products not intended for human consumption, such as plastics, rubber, rooftops, soap, cosmetics, and bio-fuel.
For example, in England, fatbergs that were dug out of sewers in cities like London and Liverpool were later reported to be processed to produce biofuel.
