Inspections were launched on Monday after livestock officials checking a plant in Chonburi last week found pork, beef and offal stored in formaldehyde.
The plant is believed to have supplied fresh meat and offal to more than 60 restaurants in the eastern province.
The crackdown in Chaiyaphum discovered formaldehyde traces in samples of squid and cow offal from 10 restaurants. The samples will be sent for laboratory tests to confirm the contamination before legal action is launched, said provincial public health chief Dr Wachira Botphaiboon.
“Formaldehyde solution is banned under the Food Act of 1979. Violations are punishable by up to 2 years imprisonment, a 20,000 baht fine, or both,” Wachira warned.
He said public health officials will continue inspecting restaurants in the province, targeting at least 10 in each subdistrict to keep people safe.
Eating food contaminated with formaldehyde can result in nausea, diarrhoea, stomach ulcers, headache, chest pain and even death, said Wachira.
“If the solution touches the skin it can cause rashes or burning, so vendors of formaldehyde-spiked foods are also risking their health.”
He said customers at hotpot and barbecue restaurants should avoid fresh meat and seafood that have a vibrant colour and strong chemical smell. He advised those cooking at home to buy their ingredients from reliable sources, such as markets certified by the Department of Health, and make sure that raw meat is cooked thoroughly.