China's quality supervisor said Wednesday that it is organizing a new round of inspections on tableware containing melamine after finding use of poisonous materials in such products.

Started on Tuesday, the inspection will last until May 15 as a follow-up to a nationwide test on melamine tableware last December, said the General Administration of Quality Supervision, Inspection and Quarantine (GAQSIQ).

The clampdown will target unlicensed and unregistered melamine tableware makers and those who use urea formaldehyde resin, a substance that could produce carcinogenic chemicals when heated, and other illegal ingredients in production, said the GAQSIQ.

The watchdog said investigators had recently found some tableware manufactures using urea formaldehyde resin to produce tableware,a substitute for melamine, which is safe but more expensive.

Previous tests showed all melamine tableware made by legal manufacturers and sold in China's supermarkets and medium-and large-sized stores are safe, said the GAQSIQ in January.

Chinese media reported last December that 80 percent of melamine tableware sampled from five chain stores and eight wholesale markets in Beijing contained urea formaldehyde resins or other ingredients that were poisonous when heated.

Most reports cited the test results of the Hong Kong-registered International Food Packaging Association (IFPA) and the Beijing-based Kaifa Environment Protection Technology Consulting Center.

The two institutions were "incompetent and incapable" of conducting tests and their test samples, inspection procedures and conclusions were not scientific, said the GAQSIQ in January.

(Xinhua News Agency April 16, 2009)