Recycled cooking oil, sometimes tainted with bleach — and proven to be deadly — is on sale at many open markets, an expert has warned.
Many consumers are lured into buying these oils through packaging which often resemble well-known brands.
However, some of the oil is recycled material and has been treated with bleach to make it look more attractive to consumers, said Worawit Kittiwongsunthorn, director of the 8th regional medical science centre, Udon Thani.
"Used cooking oil contains cancer-causing substances," he said at a food and health conference.
Organised by Thai Holistic Health Foundation, BioThai, and Foundation for Consumers at Muang Thong Thani, the conference ends tomorrow.
Consumers find it difficult to differentiate between bleached cooking oil from normal products as the look and smell is similar.
Some traders package it in bottles or plastic bags bearing the logo of popular cooking oil brands.
But the bleached cooking oil tends to be sold at lower prices at open markets near construction sites and low-income communities, he said.
Consumption of cooking oil in the country is estimated at around 1.2 million tonnes per year. About one fifth of this oil is recycled oil, Mr Worawit
said.
Of the used oil, only about 20 million litres are recycled into biodiesel fuel, he said, adding the remainder either goes to waste or into the recycling
process.
But he had no official records of how much of the used oil ends up being recycled.
In the recycling process, he said, the used oil is bleached to make it clear and look like fresh cooking oil.
Recycled oil either ends up in the animal feed industry or it goes on the black market where it is repackaged as pure cooking oil and sold in open markets, the director said.
Mr Worawit said he was worried when he saw bleaching machines being openly exhibited at an exposition in Bangkok two years ago.
He said the machines used to be sold only through an online shopping website operated by manufacturers in China.
"And the machines were on display next to a packaging machine," he said.
The director said people preferred selling used oil to cooking oil dealers than on the biodiesel market because of the higher profit margin.
One litre of cooking oil costs up to 42 baht while a litre of biodiesel can be sold for only 30 baht.
Thai Edible Oil Co Ltd marketing director Busakorn Onpradit said bottled cooking oil can be more difficult to imitate, thanks to the packaging technology and the plastic lids which are specially designed for each brand.
She said the company found some cooking oil packaged in plastic bags without a brand name, and sold at low prices, to be suspicious.
Sometimes the oil was not clear enough and it sometimes contained tiny particles.
Ms Busakorn suggested consumers buy their cooking oil from trustworthy outlets and always check the packaging and the oil inside.
To help solve the problem, Mr Worawit was now trying to work with provincial administrations to launch their own compact factory to turn used oil into biodiesel fuel for local use.