Government officials battling negative press coverage say New Zealand milk is safe to drink despite questions over the use of a fertiliser meant to help protect waterways from nitrate poisoning.
This week it was announced use of fertilisers containing dicyandiamide (DCD) would be suspended after small levels of DCD were found in some dairy products.
On Friday, America's Wall Street Journal described DCD as a toxic substance, and questioned whether New Zealand milk was safe to drink.
But Ministry for Primary Industries director-general Wayne McNee said in a statement the amount of small DCD residues found posed no food safety risk.
"DCD is not melamine. It is a different chemical and has none of the toxicity that melamine has."
Residues were only found in some milk powder products and not in products such as butter and cheese.
DCD - found in Ravensdown and Ballance's eco-n and DCn - has been used by less than five per cent of dairy farmers, who applied it only twice a year. It helps prevent nitrogen leaching into waterways and reducing nitrous oxide gas emissions.
"Now that its use has been suspended, it is not possible that any New Zealand dairy produce currently in production will have DCD residues in it," Mr McNee said.
DCD fertiliser use was suspended because international dairy customers expect New Zealand products to be residue-free, he said.
The chemical became an issue after organisations such as the US Food and Drug Administration added it to a list of substances to be tested for. However, an international standard has yet to be agreed for DCD.
Labour's trade spokesman Clayton Cosgrove told Fairfax the decision to sit on the news could be seen as trying to hide the problem.
But dairy giant Fonterra said the September chemical discovery needed to be confirmed and it was not "material" information ahead of opening up the company to outside investors in November.