The West Coast dairy company at the centre of the latest product contamination scare with China says it has totally changed the way it tests its lactoferrin production.
About $2 million worth of the product has been quarantined in China after nitrate levels up to 15 times what is allowed here were found in two batches of lactoferrin powder.
Head of Westland Milk Products Rod Quin says his company had been doing composite testing of several days' production, but the Chinese picked up the contamination by testing more thoroughly, and that's what they are doing now.
"We want to do that across the whole industry, and moving to testing every day's production taking place immediately. That will be a change in the way that we test lactoferrin."
Mr Quin says the nitrate spike was caused by a one-off automation problem at the company's Hokitika plant where cleaning products weren't properly flushed.
Two batches of the powder, which is a dairy protein ingredient used in small amounts in formulas and products such as yoghurt, are involved in the contamination.
The Ministry for Primary Industries has revoked export certificates for four of the co-operative's consignments.
One batch tested 610 parts per million and the other 2198 parts per million.
The maximum allowed in New Zealand is 150 parts per million.
The Ministry for Primary Industries and the Ministry of Foreign Affairs and Trade are working with authorities in China.
Westland Milk Products says the levels are not a food safety risk and the Ministry for Primary Industries says the risk is negligible.
However, the problem is that the 390 kilograms of product wasn't found during routine testing before it was sent to China.
The company says early investigations show the contamination was due to cleaning products not being properly flushed.
Bad timing - PM
Prime Minister John Key says the contamination scare could not have come at a worse time.
Mr Key says the elevated levels of nitrate found in batches Westland lactoferrin powder sent to China did not pose a health risk but he says it is unhelpful that it is happened now when the Government is still dealing with the Fonterra botulism scare.
Export New Zealand meanwhile says the latest milk-powder product contamination is unfortunate but must be put in perspective.
Export New Zealand chief executive Catherine Beard says the problem was picked up quickly.
Ms Beard says this latest issue is not a risk to health and hopes export markets will keep a sense of proportion.