Dicyandiamide poses no food risk but fertiliser companies have suspended sales

New Zealand has been struck with a food contamination scare: laboratory tests have revealed traces of dicyandiamide (DCD) in milk, one of the country’s most prized exports.

According to the companies involved, and government authorities, the contaminated milk presents no danger to the public. But fertiliser companies have nonetheless voluntarily suspended sales of the chemical, which is applied to pasture land to reduce greenhouse gas emissions and leaching of nitrogen into waterways.

On 24 January, dairy company Fonterra announced the suspension following the discovery of ‘very low levels’ of DCD in test samples of dairy products. This was followed by assurances from Fonterra and the New Zealand Ministry for Primary Industries (MPI) about the safety of contaminated milk, citing trade as the reason for the intervention.

There is no internationally agreed ‘safe limit’ for the chemical. Therefore, buyers expect products to be completely free of it, the MPI says.

The European Commission has published an opinion on acceptable daily intake of DCD. According to MPI director general Wayne McNee, based on the highest contamination reading, a 60kg person would have to consume more than 130 litres of liquid milk or 60kg of milk powder to reach the Commission’s limit.

The MPI adds that in any case very little milk is involved. DCD has been used by under 5% of the country’s dairy farmers, who applied it only twice a year. Each application leaves traces for no more than a few days, meaning only very small numbers of New Zealand cows could have come into contact with DCD, and even then only in very limited time frames.