Food safety is once again being put into the limelight following media reports last week that a "significant portion" of used cooking oil is being recycled and returned to people's dining tables across China.
Catering industry insiders and food safety experts say huge profits, inadequate supervision and the difficulty of disposing of used cooking oil are the main reasons that used oil is collected from kitchen waste and reused as cooking oil.
Huang Fenghong, deputy director of the Oil Crops Research Institute at the Chinese Academy of Agricultural Sciences, told the Global Times that, after seven years of field research, his research team has concluded that the use of recycled oil is rampant in some areas, especially where cash-strapped migrant workers and students are major diners.
Recycled cooking oil, dubbed "drainage oil," is refined from discarded kitchen waste and reused in the preparation of meals at restaurants and canteens.
"The use of drainage oil will put the public's health in peril because it may contain heavy metal, waste antibiotics or aflatoxins, a highly toxic substance that could cause cancer," he said.
Huang did not specify how much drainage oil China consumes each year, saying it is difficult to calculate the figure.
Earlier, He Dongping, a nutrition professor at central China's Wuhan Polytechnic University and a member of Huang's team, told the China Youth Daily on Thursday that people in China consume about 2 to 3 million tons of drainage oil a year.
"China consumes about 22.5 million tons of cooking oil annually, which means that one in 10 meals in the country may be cooked with illegal cooking oil," the newspaper quoted him as saying.
Although Huang said the media misinterpreted He's statements, which only suggested the total amount of China's recycled oil annually, the shocking report renewed concerns among authorities, experts and citizens over food safety in China.
In Wuhan, the capital of Hebei Province, the Food and Drug Bureau set up a hotline Saturday to process citizens' complaints about the use of drainage oil by restaurants or cafeterias.
A hotline worker who refused to be named told the Global Times Sunday that the line had been busy ever since it was opened. People called in to report what they said might be recycled oil at restaurants, or to report people allegedly involved in the illegal recycling business.
"Many recycling plants are based in the suburbs," Chen Debin, general manager of NZBM, a Beijing-based fast food chain with over 10 outlets in China, told the Global Times that recycling drainage oil for cooking meals is an open secret in the catering industry, and especially so for small restaurants, unlicensed restaurants, roadside food stands and in-house cafeterias.
Chen said that his restaurants don't practice oil recycling.
"They send workers to collect kitchen waste from restaurants. It is normal if they process it into pigwash or soup, but some illegal processors sell it to the black market as cooking oil," he said.
Handing over kitchen waste to private processors seems to be the only way to get rid of the waste, since the sanitation department has stopped collecting it, he said.
Collecting waste oil has become a lucrative industry in China since prices of edible oil surged between 2007 and 2008, according to a report by the Xinhua News Agency on Saturday.
Chen said collectors sometimes fight to get the right to obtain the waste. Some even pay a high price to bid for the right to collect. Whenever a new restaurant opens, there will be oil collectors contacting the restaurant owner.
"They usually pay restaurants 1,000 ($147) to 6,000 yuan each year, and more for hot-pot restaurants, since they discharge more waste oil," Chen said.
Chen did not comment on how hotels deal with their waste, but Zeng Wei, manager of an oil-refining plant in Wuhan, told Xinhua that some plants would pay more than 40,000 yuan per year to get a hotel's kitchen waste, due to the potential profits.
One ton of cooking oil made from kitchen waste costs around 1,000 yuan, while edible oil costs over 6,000 yuan per ton, according to Zeng's estimation. A processor could easily sell one ton of recycled oil at half the price of normal oil to make 2,000 yuan.
James Jia, a student at China Agricultural University, told the Global Times that he sees a waste collection wagon at the back door of his university's cafeteria pumping something from the drain at around 8 pm every day.
"They have never done this in the daytime. I don't know what they do with the substance they pump from the drain," he said.
Lack of inspection is another reason dirty oil continues flowing into the market.
"The processing and trading of it is supervised by the Administration of Industry and Commerce. Once the oil travels to the dining table, it is under the inspection of the Ministry of Health," Chen said. "No specific department is tracking down the issue during the entire process."
Huang appealed to the public to stay away from buying and using cheap oil, like blended oil or oil without clear sources, saying the public has difficulty in telling whether oil is of good quality or not.
On Thursday, the State Food and Drug Administration issued a high-profile crackdown on illegally recycled cooking oil, calling on all levels of inspection agents to punish manufacturers providing dirty oil and restaurants purchasing oil of unclear origin.
"If food-service providers are found to be using cooking oil from an unclear source, or if they have bought 'drainage oil,' their operations will be immediately halted and they will be dealt with in accordance with the law," said a notice posted on the administration's website.
He Dongping said the National Grain and Oil Standardization Committee is stepping up efforts to draft measures and standards on testing drainage oil and the management of drainage oil refined from kitchen waste. The measures are subject to evaluation next month.
China's white paper on drainage oil, drafted by the committee, is due to be submitted to the state authorities by July.