By Nao Nakanishi

HONG KONG, May 17 (Reuters) Foreign buyers of Chinese food are asking for safety tests following the melamine pet food debacle, threatening the country's competitive position in a wide range of markets, including organic ingredients.

Industry officials said U S and other firms had demanded a certificate that farm products were free of melamine.

Their comments came after a U S Food and Drug Administration team visited China to investigate how melamine, a chemical product, got into pet food, killing at least 16 pets in the United States and leading to a recall of more than 100 brands of pet food.

Costs for such safety checks are expected to soar, especially as it would take time for the country to build up reliable nationwide quality controls.

''This scandal has had severe consequences for the whole industry,'' said Chuk Ng, general manager of Nutrogen (Dalian) Co. Ltd, a company specialising in organic and non-genetically modified (GMO) farm products.

''Now the European and U S clients are checking every batch of products coming from China ... The GMO test is one. Now you add tests for melamine or other heavy metals or pesticides, the costs are very high, too high,'' Ng said.

Pressured by the U S government after the melamine breaches, Beijing has pledged to act on food safety and announced an industry clean-up that would bring inspections for fertiliser, pesticides and additives in livestock feed.

Foreign buyers, reluctant to take risks, are sending large quantities of food samples to international testing specialists such as Eurofins Scientific or SGS Group.

JAPAN, OWN SYSTEMS The industry officials said Japan, which accounts for about a quarter of China's farm product exports, had also recommended importers check for melamine in Chinese products, such as rice flour or wheat gluten, for use in animal feed.

''The safety tests for raw materials are likely to get tougher,'' said a senior official from a Japanese food processing plant in China.

''Eventually they could demand traceability similar to that for non-GMO products ... which would raise costs. Given higher costs and credibility, there's a question if you would still want to buy raw materials from China.'' A year ago Japan tightened safety checks on farm products from China, which has angered Beijing. The new rules require checks for nearly 300 pesticides and chemicals residues at loading ports as well as at discharging ports.

Asked how to guarantee the quality of food imported from China, an official in charge of food safety at one of Hong Kong's largest food retailers said: ''It's very important to get system in place for traceability all the way back in the supply chain.

''When you have traceability, you can then have accountability. I think this is what China lacks.'' REUTERS SKB HT1702