Japan will introduce new criteria on chemical residues in food next week (29 May), which are being considered among the strictest in the world. Authorities will test 302 food products for 799 agricultural chemicals, enforcing 54,782 maximum residue limits. Included in the screening list are 448 pesticides.
It is thought that most food analysis laboratories in China do not yet have the resources to test for each of these residues.
The ministry of commerce said in a risk assessment that meat products, vegetables, fruit, seafood, grain and tea will be particularly at risk of being refused at customs.
For example, there will be 339 residue limits on onions imported into Japan under the new standards, compared to only 77 before. In a pre-test conducted by Japan in 2005, China's onions failed to meet requirements on five residues, said the ministry.
With some 710,000 tonnes of onions (valued at US$45 million) being exported to Japan last year, Chinese exporters are fearful of damage to trade.
The director of agriculture company Haitong Group told Xinhua news that Chinese laboratories are able to detect only 230 kinds of agrochemicals on agricultural products.
The chief of the company's research institute, Du Weihua, told AP-Foodtechnology.com that the firm still needs to buy standard samples of the new agrochemicals on Japan's list in order to detect them.
In other products too, residue limits have significantly increased. For tea, which accounted for US$79.8 million in export sales to Japan in 2005, there are now 276 residue limits compared to only 83 before.
And for chicken, 99,000 tonnes of which was exported to Japan last year, there are now 363 standards in the new system, compared to only 20 before.
In the China Economic Weekly, Cheng Xiancui, the Chief of Agency of Foreign Trade in Yantai, Shangdong Province, was quoted as saying that the new list will have a "serious impact", blocking around US$700 million worth of agricultural exports.
Additional inspection and quarantine procedures will also increase costs and time for exporters.
China's ministry of commerce has said it is the first time it has done a report on another country's import policy. Japan accounts for about a third of all China's export produce.
Some in the industry feel however that the new regulations will improve quality standards, from farm to fork, for China's food products.
The country's agriculture sector is also preparing for changes to European Union regulations on pesticides, due to enter into force on 1 August.