Trying to keep genetically modified organisms (GMOs) from contaminating traditional crops could cost up to a fifth of the total production cost, a study concludes.

This figure comes from a report done by the national agricultural research organization, Agroscope, and Zurich’s Federal Institute of Technology (ETH).

Switzerland currently has a 2013 moratorium in place for GMOs.

But in the meantime, Swiss decision-makers must come up with a coherent policy.

Gregoire Albisser, the agriculture economist who lead the study, said it aims to help authorities establish that policy.

According to the study, the extra cost of shielding normal crops from GMOs ranges between one and 20 percent of production costs.