To ensure the safety of food sold to the public, the Jakarta authorities have been checking traditional markets and food processors across the capital to see whether formaldehyde, or other industrial chemicals, were being used as preservatives.

Jakarta Police chief Insp. Gen. Firman Gani said on Friday that the police had started the checks on Thursday, with the Jakarta Food and Drug Office (BB-POM) conducting the preliminary tests on the food products.

"We will arrest those who produce or sell formaldehyde-treated food," he said.

To huge media coverage, the BB-POM announced on Tuesday that a high concentration of formaldehyde is being added to various kinds of foods, such as tofu, noodles and salted fish, to keep them fresh longer.

Formaldehyde is a chemical widely used in fertilizers, plywood, as an industrial fungicide, and as a preservative in mortuaries and medical laboratories. Many producers and traders use it to delay the onset of decay and mold in food because of its low price and easy availability.

When formaldehyde is present in the air at levels exceeding 0.1 ppm, some individuals may experience health effects such as watery eyes, a burning sensation in the eyes, nose and throat, coughing, wheezing, nausea and skin irritation.

Excessive intake of formaldehyde could cause severe pain, vomiting, heart, lung, and brain disorders, coma, and possible death. It could also effect the nervous system and kidneys.

Despite the BB-POM's assurances that not all tofu, noodles and salted fish sold at traditional markets and supermarkets were laced with the chemical, its report on the high content of formaldehyde in more than half of the samples taken from 50 markets in Greater Jakarta and Banten between November and December has resulted in many people shunning these types of foodstuff.

Firman said that the police were targeting large-scale traders and producers rather than small-scale traders, who were often unaware of the contents of the food they sold.

"We will first question the traders to find out where they sourced the foodstuffs. Then, we will track down the producers," he added.

Jakarta BB-POM director Atiek Herwati said that her agency would also make sure that the suppliers of the formaldehyde were punished.

"We have conducted checks on factories that produce and sell formaldehyde and other dangerous substances. If we find that the producers have being selling large quantities of formaldehyde without keeping records of whom they sold it to, then we will take strict action against them as it may have found its way into the food industry," she told The Jakarta Post.

The absence of a specific law on food and beverages, Firman said, would not stop the police as they could use various pieces of legislation, including the Consumer Protection Law and the Criminal Code, to charge the traders and producers.

Governor Sutiyoso had also instructed his subordinates to carry out raids against the producers of processed food containing formaldehyde and other harmful preservatives and take resolute action against all involved.

He added that his administration would impose administrative sanctions on those found guilty of treating foodstuffs with hazardous chemicals, including revoking their business permits.