The Consumer Protection Foundation has found one McDonald's outlet uses old cooking oil which contains a health-risk substance higher than the safety standard in its fried chicken.
Foundation representative Patchara Klaewkla yesterday said the group examined fried chicken samples from 11 outlets that sold fried chicken in Bangkok between Jan 21 and 23.
According to Mr Patchara, the McDonald's's branch in the Center One shopping mall at Victory Monument was found to have polar compounds at more than 25% of the food weight _ a Public Health Ministry safety standard.
Compounds beyond the safety limit could cause high blood pressure, coronary artery disease, heart attacks and paralysis, Worawit Kittiwongsunthorn, director of the Regional Medical Sciences Centre 7 in Ubon Ratchathani, said.
The foundation will send a letter to the McDonald's branch asking it to rectify the problem, Mr Patchara said.
He said the ministry's regulation limits the polar compounds to no more than 25% in food and violators may be fined up to 10,000 baht. The compounds are often found in old cooking oil.
Mr Worawit said three other samples from fried chicken restaurants were also found to be cooked in oil which nearly hit the safety limit.
Deteriorated cooking oil could also contain a polycyclic aromatic hydrocarbon (PAH) substance which places consumers at risk of cancer.
Mr Worawit said many fried chicken shops mix new oil with old oil, and this practice could have the effect of multiplying the polar compounds.
Another concern is that many shops buy old oil which has been subject to a process of filtering and colour bleaching to look new, Mr Worawit said.
The oil must not be used more than three times as it will deteriorate, he added.
A McDonald's spokesman said its quality control unit will look into matter.
