Testing for a toxic agricultural substance in New Zealand dairy products has found no traces of it after mid-November last year.
The Ministry for Primary industries and the dairy industry conducted voluntary testing after dicyandiamide (DCD) residues were found in low levels in 10 out of 100 samples of whole milk powder, skim milk powder and buttermilk powder made with milk from September last year.
Some fertiliser companies in New Zealand voluntarily withdrew DCD products from the market after it was revealed that trace quantities had appeared in some milk samples.
The finding caused concern among international customers of dairy giant Fonterra, and the Government last month expressed concern about the potential damage to the industry's image.
MPI director general Wayne McNee today said the ministry and the dairy industry had carried out extensive testing to build up a comprehensive picture of the presence of DCD in New Zealand's milk supply.
The tests found no traces of DCD in milk collected from New Zealand farms after November 13 last year.
"We are releasing the core findings of the testing today to be as open as we can with our markets and customers, despite the fact that the quantities of DCD found in our dairy products creates absolutely no food safety risk whatsoever," Mr McNee said.
Nearly 2000 samples of dairy products were tested from all the major dairy companies.
The testing was targeted on dairy products using milk collected during spring last year from the less than 5 per cent of dairy farmers who used DCD on pastures.
Minute traces of DCD have been found in various dairy products already in the supply chain from a variety of companies.
MPI said it could be up to several years before DCD could be used on pastures again.
Health authorities in Taiwan launched an investigation into whether the tainted product reached its shores, while China requested detailed information from New Zealand authorities after consumers raised concerns.
Fonterra last month said the testing had found "only minute traces" of DCD in samples of some products, most of which were sent to export markets.
It said the traces were around 100 times lower than acceptable levels under European food safety limits.
Mr McNee said the results had been coming in steadily, including as late as last week.
Minute traces of DCD were found in various dairy products already in the supply chain - and some products would still be in the supply chain.
"However, there remains no food safety risk. All traces are significantly below the European Commission's daily intake levels for DCD.
"Importantly, tests on products made from milk collected on farms after November 13, 2012 show no traces of DCD at all."
Mr McNee said DCD was applied as a fertiliser in spring and no DCD had been applied since then.
"These findings confirm our expectations. There's no DCD in fresh milk now, and the quantities that were found in products from when DCD was being applied are at very low levels, and our dairy products are safe."
Tests were carried out on 1994 products made since June 1 last year, with a focus on products manufactured during and shortly after the DCD application period from then to September 28 last year.
A total of 371 detections of DCD were made, with the last diary product to contain DCD made on November 12 last year.
Of the 602 products tested which were made from milk since November 13 last year, no DCD was detected.
The highest level recorded was 2.4 parts per million, from skim milk powder manufactured on August 9.
Only nine of the 1994 samples exceeded one part per million. Those products were all concentrated and, on a liquid milk basis, all results were well below one part per million.
Mr McNee said the testing programme would be ongoing.
"There will be no DCD applied to pasture from now on. At some point it may be applied again if a minimum standard is put in place."
Asked what could be done to ensure farmers who still have DCD did not apply it, MPI standards deputy director general Carol Barnao said it was applied under very tight controls by approved applicants.
"There's the ability to have very strong traceability."
MPI was also working with Customs to make sure no DCD could come into the country.
- APNZBy Matthew Backhouse @Mbackhouse Email Matthew