A Panamanian importer is mainly culpable for the deaths of up to 100 people last year who used cough syrup which had a toxic chemical as an ingredient, Chinese officials said yesterday.

Wei Chuanzhong, deputy director of the General Administration of Quality Supervision, Inspection and Quarantine (GAQSIQ), described the chain of events uncovered in an investigation:

11,349 kilograms of "TD" glycerin, which can be used as a substitute for glycerin in industrial use, was sold to a Spanish company in 2003 before being forwarded to a Panamanian trader the same year.

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It contained 15 percent diethylene glycol, an industrial solvent used in paint and antifreeze, while glycerin is a similar but more expensive compound frequently used as syrup in medicines and in toothpastes.

The Panamanian merchant later renamed the solvent as "pure glycerin", tweaked the expiry date to indicate it would be valid for another three years, and sold it to a cough syrup manufacturer.

"The two trades were separate and the Chinese companies were not informed of the resale," Wei told a press conference organized by the State Council Information Office.

"The Panamanian trading company is mainly responsible because it changed the scope of use and shelf-life of the product.

"By the time the Panamanian drug manufacturer used the chemical, it had been expired for two years."

The Chinese companies had made it clear in their export paperwork that the material was for industrial, not medical, use.

The deaths started last summer; and in October, China launched an investigation at the request of Panama. A preliminary probe result was submitted by the year-end but some foreign media have recently raised the issue, holding China directly responsible for the deaths.

Some other scandals involving Chinese exports, such as the "toxic" toothpaste and wheat gluten tainted with the chemical melamine, have also shaken confidence in made-in-China products.

China launched another investigation last month, whose results Wei unveiled yesterday.

He also dismissed concerns about exported Chinese toothpaste containing diethylene glycol, saying there was "no sound evidence" to show that the chemical was dangerous in low concentrations.

Thousands of tubes of made-in-China "Mr. Cool" and "Excell" branded toothpaste have been seized in the Dominican Republic, Panama, Costa Rica and Nicaragua for containing diethylene glycol ranging from 2.5 percent to 4.6 percent.

But he cited research by Chinese doctors which says toothpaste containing up to 15.6 percent of diethylene glycol has been found safe even after prolonged use.

"But to better safeguard the health of the public, we'll issue clear guidelines for the use of diethylene glycol in toothpaste," he said.

Li Yuanping, director of the AQSIQ's food safety bureau, also criticized some foreign media for stoking fears about the safety of Chinese food and drugs.

He said they had "wantonly" reported on so-called unsafe Chinese food products, but records show that more than 99 percent of Chinese food exports to the United States in the last three years had met quality standards about the same, or even higher, than the equivalent figure for US food exports to China during the same time.

He said China had found at least 35 shipments of frozen meat from the US to China containing the salmonella bacteria and veterinary medicine residue since last April.

"But one company's problem doesn't make it a country's problem," he said. "If some food is below standard, you can't say all the country's food is unsafe - just like aircraft are believed to be the safest mode of transport, but we do see air crashes some times."