New Zealand's Fonterra, the world's biggest dairy exporter, caught up in a contamination scandal this month, said yesterday it had also been forced to withdraw 42 tonnes of milk powder bound for China because of high nitrate levels.
The company said a shipment of powder had been halted at the Chinese border in May after tests showed nitrate levels higher than allowed in China, although it had been approved for export after testing in New Zealand.
Nitrates occur naturally in vegetables, water and soil and can be used in fertilisers and preservatives. Excessively high levels can be toxic.
Fonterra had to apologise for a milk powder contamination scare in China after contaminated whey protein concentrate had been sold to China, Malaysia, Vietnam, Thailand and Saudi Arabia, and used in products including infant milk powder and sports drinks.
Fonterra's food safety and quality director, Ian Palliser, said the milk powder showed nitrate levels of between 1.4 parts per million and 1.8 ppm when it was shipped from New Zealand, but showed higher levels in Chinese tests. "The limit is two parts per million in China and the product tested at somewhere between 2.4 ppm and 2.8 ppm," Palliser said.
China had a much lower threshold for nitrate levels than New Zealand, where levels of up to 5 ppm are considered safe for domestic consumption, he said. The levels were "not a food safety issue whatsoever", Palliser said. Fonterra said it had been in full control of the affected product and none had reached the retail supply chain.
In Hong Kong, a spokesman for the Centre for Food Safety said infant formulas in the city were not tested for nitrate under its routine food surveillance programme. The centre would follow up the incident with New Zealand authorities.
Wellington has voiced frustrations over Fonterra's foot dragging in disclosing the contamination issue.
During a visit to China yesterday, New Zealand Foreign Minister Murray McCully sought to distance the country from Fonterra's woes.
"Fonterra has some work ahead of it in rebuilding Chinese consumer confidence," he said in Beijing after meeting State Councillor Yang Jiechi and Foreign Minister Wang Yi .
"We expect from our exporters that there should not be any mistakes. When Fonterra disappoints customers, they also disappoint New Zealand."
Yang urged New Zealand to improve food safety, state media reported.
"We hope the New Zealand side will appropriately handle food safety issues, including the safety of dairy products, exported to China, and substantially ensure Chinese consumers' interests," Xinhua reported Yang as saying.
Fonterra's much smaller competitor, Westland Milk Products, had export certificates revoked this week for a small quantity of the protein lactoferrin due to unacceptable levels of nitrates.