BEIJING - China has banned toothpaste companies from using diethylene glycol -- a thickening agent used in antifreeze -- in its latest move to raise confidence in the country's food and drug safety procedures, the official Xinhua news agency said Wednesday.

"China forbade domestic enterprises to use diethylene glycol as the raw materials for toothpaste as of Wednesday after a number of countries banned the selling of toothpaste containing this chemical," Xinhua quoted the country's safety watchdog, the General Administration of Quality Supervision, Inspection and Quarantine, as saying.

Chinese-made toothpaste containing diethylene glycol has been banned in North and South America and Asia. And two brands of toothpaste sold in Spain were pulled from store shelves after the substance was found, the European Union said Tuesday.

Although there have been no reports of health problems stemming from the toothpaste, dozens of people in Panama died last year after taking medicine contaminated with diethylene glycol imported from China. It was passed off as harmless glycerin.

The announcement is the latest in a string of moves by China to clarify murky regulations, tighten enforcement and clean up graft -- factors underpinning its poor food safety record -- as it struggles to salvage its reputation as a safe exporter.

In recent weeks, importers of Chinese goods, especially the United States, have grown extremely wary as the list of products tainted with deadly toxins and dangerously high levels of chemicals grows daily.

The product safety watchdog also ordered small, loosely regulated food producers to clean up their act and announced stricter rules for approving new drugs. The action came a day after the former head of China's food and drug agency was executed for corruption.

China's small-scale food producers have been accused of unsanitary production conditions, using tainted or substandard ingredients and failing to register with authorities. While their products generally are sold only in local areas, their continued existence helps explain why China is facing a food crisis.

The General Administration of Quality Supervision, Inspection and Quarantine warned on its Web site that small-scale producers will be closed unless they renovate their operations to meet hygiene standards.

Those manufacturers must also avoid using recycled ingredients, unapproved additives and banned substances, it said.

By 2009, their numbers are expected to be halved, with all properly certified by 2012, the administration said.

Additionally, all food exported from China will have an inspection and quarantine symbol to guarantee safety starting in September, it said.

"After the recent spate of product quality or safety problems, the Chinese government has attached great importance to this issue," Commerce Ministry spokesman Wang Xinpei said, according to comments posted online. However, he added, "problems in individual products should not be extended to the overall quality of China's exported products."

The quality administration did not specify how it defines small-scale producers in its crackdown, or give other details. But it has said that about 350,000, or 78 percent, of China's food processing operations each employ 10 people or fewer.

The agency also said about half -- or 223,297 -- of the factories it inspected nationwide were not completely certified. Another 164,149 had no certification at all, it said.

Most manufactured commonly consumed food like rice, wheat powder, soybeans, wine and cooking oil.

Last month, Chinese authorities said they had closed 180 food factories since December after inspectors found formaldehyde, illegal dyes and industrial wax being used to make candy, pickles, crackers and seafood. All had fewer than 10 employees each.

Another regulating agency said it shut 152,000 unlicensed food producers and retailers last year for making and selling fake and low-quality products.

Zheng Xiaoyu, who headed the State Food and Drug Administration from 1997 to 2005, was executed Tuesday. In a commentary, the Communist Party's mouthpiece People's Daily newspaper said the execution was warranted because of the serious consequences of approving untested medicine in return for millions of dollars in cash and gifts.

"He damaged the interests of the country and the people to a large extent," the newspaper said.