Gutter oil (simplified Chinese: 地沟油; traditional Chinese: 地溝油; pinyin: Dìgōu yóu) is a term used in China and Taiwan to describe illicit cooking oil which has been recycled from waste oil collected from sources such as restaurant fryers, sewer drains, grease traps and slaughterhouse waste. Reprocessing is often very rudimentary; techniques include filtration, boiling, refining and the removal of adulterants. It is then packaged and resold as a cheaper alternative to normal cooking oil. Another version of gutter oil uses discarded animal parts, animal fat and skins, internal organs, and expired or otherwise low-quality meat which is then cooked in large vats in order to extract the oil. Used kitchen oil can be purchased for between 859 and 937 dollars per ton while the cleaned and refined product can sell for 1,560 per ton. Thus there is great economic incentive to produce and sell gutter oil. It is estimated that up to one in every ten lower market restaurant meals consumed in China is prepared with gutter oil. This high prevalence is due to what Feng Ping of the China Meat Research Center has made clear: "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."
The first documented case of gutter oil in Taiwan was reported in 1985. In subsequent investigation, 22 people were arrested for involvement in a recycling oil ring over 10 years based in Taipei. The worst offender was sentenced to 7 years in prison.
Additionally, some reported an earlier incident in Taiwan in the 1960s, where "Trench Oil" was imported from Japan to Taiwan and then used in food processing.
In September 2012, an ongoing investigation into the suspected use of gutter oil as a raw material in the Chinese pharmaceutical industry was revealed. A massive scandal involving 240 tons of gutter oil in Taiwan affecting hundreds of companies and thousands of eateries broke in September 2014, some of which may have been exported overseas.
Production and distribution
The collected waste oil is sold to local workshops or small factories for cleaning and packaging. When sold to workshops it is often transported on the back of bicycles by peddlers who are paid a monthly fee and then the oil is held in 55 lb dingy round barrels at the workshops until it is processed. On other occasions the oil goes to industrial cooking oil refiners for further processing before it finally reaches its end purpose. The industrial oil refiners are usually legitimate producers that sell the processed oil for use in the chemical or energy industries. Gutter oil is perfectly suited as a raw ingredient for producing soap, rubber, bio-fuel and cosmetics. However, the refiners can also have other intentions as the prices attained by selling it as cooking oil are much higher than if it is sold to the chemical or energy industries. There are no proper rules nor protocols in place to prevent purchases from or sales to entities intending to use the oil for human consumption. So it is very common for individuals or wholesalers to purchase oil from these industrial refineries and then resell the oil to restaurants or to end consumers. There have even been some cases where the industrial oil refiner will package the oil under a unique brand name and sell it as legitimate oil in retail outlets as opposed to just selling directly to restaurants. Some lower market restaurants have long-term purchase agreements with oil recyclers for selling their used oil.
Lower market restaurants and street vendors are the biggest end buyers of gutter oil as they operate with lower profit margins than bigger restaurants. Moreover, it is also one of the largest kitchen expenses for restaurants, so obtaining cheaper oil can allow an offending restaurant to reduce its overall expenses. Chinese food is generally heavily dependent on oil due to most foods being fried so cheaper meal prices for the many cost conscious consumers are possible if gutter oil is used instead of virgin oil. The situation becomes more serious due to the fact that it is hard to distinguish reprocessed gutter oil from legitimate oil. Bleach is used to transform gutter oil's dark color into a more natural one and alkali additives are used to neutralize the abnormal pH caused by containing high concentrations of animal fats.
Gutter oil has been shown to be very toxic, and can cause diarrhea and abdominal pain. There are also reports that long-term consumption of the oil can lead to stomach and liver cancer as well as developmental disabilities in newborns and children. Testing of some samples of gutter oil have revealed traces of polycyclic aromatic hydrocarbon (PAH), a dangerous organic pollutant capable of causing cancer with long-term consumption. There is also potential for gutter oil to contain aflatoxins, highly carcinogenic compounds produced by certain molds. Zeng Jing of the Guangdong Armed Police Hospital said about gutter oil "Animal and vegetable fat in refined waste oil will undergo rancidity, oxidation and decomposition after contamination, and produce toxic substances such as arsenic. It will cause indigestion, insomnia, liver discomfort and other symptoms".
Regulations and law enforcement
Current Chinese law states that industrial animal fat is not allowed for use in food products because it doesn't meet basic hygiene standards and contains high levels of potentially toxic chemical substances. The national and local governments are currently researching ways to test and identify gutter oil but as of 2012 there are not any nationwide standards in place to help with this process. The government is looking into methods that rely on technical equipment as well as on-site instant tests to screen suspect oil. There have already been 5 proposed tests for gutter oil but each has failed to accurately detect it.
In August and September 2011 the Beijing city government passed two new sets of regulations. The first was "On Accelerating the City's Food Waste and Waste Oil Recycling Program." Its goals are to increase daily food waste processing to 2,200 tons by 2012 and to 2,900 tons by 2015. Additionally, the intent of the regulations are to create a system that "should be a unified, standardized, and orderly processing of waste oil collection and improvement of the transportation system". The second set of regulations passed by the city of Beijing were in September 2011. They are called the "Beijing Municipal Solid Waste Regulations." The regulations specifically target the two sources of gutter oil, food waste and used oil. The central government intends for these two sets of regulations to serve as national examples, yet wants every municipality nationally to find their own solutions to the food waste and gutter oil problem.
A nationwide campaign was set in motion in August 2011 to crackdown on the widespread production and selling of gutter oil. The law enforcement campaign uncovered 100 gutter oil manufacturers and arrested more than 800 people allegedly involved in the production and sale of gutter oil. In April 2012 another crackdown occurred with an additional 100 arrests made and 13 illegal workshops closed down across 4 provinces. According to a notice released jointly by the Supreme People's Court, the Supreme People's Procuratorate and the Ministry of Public Security the death penalty will now be an option when prosecuting more serious cases of gutter oil manufacturing in the country. More severe punishments will also be given out to government and public officials who fail to properly address matters related to gutter oil. The State Council said inspectors would target edible oil trade fairs and wholesale markets and called for inspections of oil being used at restaurants, school cafeterias, work canteens and kitchens at construction sites. The State Council also stated that businesses that use recycled oil would be forced to close temporarily or lose their business license while peddlers who sell the oil could be criminally prosecuted.
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