There were two drivers that prompted our decision to test for DCD.
Two New Zealand fertiliser companies were asking us to actively support their use of DCD products as a way of reducing nitrate leaching.
At around the same time, the US FDA published details of new tests for a range of compounds - including DCD - that might be used to artificially boost protein levels in food. This testing methodology allowed for more detailed testing than had been available before.
We decided it was wise to take a look at our products. Our first priority was food safety.
We ran tests on all our products from across all our sites. We found minute traces of DCD in products made in September - shortly after the most recent application of DCD.
The levels of DCD detected were minute and at such low levels (100 times lower than recommended acceptable daily intake levels under European food safety limits) that we knew there was no food safety issue.
There was no need to panic or ring alarm bells - our products are safe.
At the same time we were conscious that there is no global standard for DCD in any food.
Without a common standard we felt there was the potential for confusion among food regulators around the world.
As the world's largest dairy producer and exporter we often take the lead on developing new food standards.
We discussed this with the government (Ministry for Primary Industries) which formed a working group which also involved the fertiliser companies and it met at various times through November 2012-January 2013.
While international standards are being developed, the fertiliser companies decided it would be best to withdraw their products - a move the Ministry for Primary Industries and Fonterra supported - and the fertiliser companies announced their decision last week.
Throughout we have worked closely with the ministry, as would be expected.
We have of course been speaking with major investors and market analysts, who have signalled they are comfortable with the approach we have taken on this issue.
The clear message coming back from the markets is that they understand the issue and appreciate that there is no food safety issue here.
Since last week's announcements, our focus has been on working alongside the Government to reassure our customers and consumers that Fonterra products are safe.
Theo Spierings is chief executive of Fonterra.