JAPAN - The import of processed frozen foods such as gyoza dumplings has been increasing steadily in recent years, and Chinese products now account for about two-thirds of such imports, according to a survey conducted by the Japan Frozen Food Association.

The survey covered the association's 34 member companies. It found that imports of processed frozen foods hit about 315,000 tonnes in 2006, a rise of about 270 per cent on the 85,000 tonnes recorded in 1997.

Chinese products accounted for 64 per cent of the 2006 imports, or about 200,000 tonnes. Imports of such products from China have increased about 400 per cent over the past 10 years.

According to the association, the Chinese imports have risen so fast because of the country's low labour costs. The ready availability of ingredients such as vegetables, seafood and meat in China is another reason, with such factors driving Japanese makers to establish joint ventures with Chinese firms, the association said.

However, the safety of the imported Chinese food has been in doubt since 2006, when pesticide residues were detected in products such as vegetables. Since then, imports of Chinese frozen foods have been rising more slowly.

Imports of Chinese processed frozen foods rose by more than 20 per cent annually from 2000 to 2002. However, it only recorded a 7 per cent increase in 2006.

A spokesman for the association said: "The impression that Chinese products are dangerous is now spreading among Japanese people. I guess that imports from China will drop if we see more incidents like this."

Despite the rapid increase in imports of processed frozen food, the country's system of safety checks on food imports remains underdeveloped.

According to the Health, Labour and Welfare Ministry, sample inspection is conducted on frozen foods to check the levels of bacteria and additives. But products such as gyoza, which contain a variety of processed ingredients, are not checked for pesticide residues. Since permitted residues and processing methods differ from one vegetable to another, and since the interrelation between the processes is complex, it is hard to accurately gauge the levels of different chemicals, the ministry said.

An official of the Health, Labour and Welfare Ministry's Import Food Safety Office said: "Even if some of the products contain agricultural chemicals, it's difficult to detect them in an inspection at the time of import."