Indicator biotechnology

Presence of genetically modified rapeseed in the environment

Due to a moratorium, Switzerland has banned the release of genetically modified organisms (GMOs) into the environment for other than scientific purposes. However, some agricultural exporting countries such as the U.S. and Canada are now cultivating them on a large scale. As a result, genetically modified plants can end up contaminating goods that are imported into Switzerland and eventually enter the environment. This risk must be curbed as much as possible to prevent the contamination of conventional agricultural crops and any damage to biodiversity.

Assessment of the state
impossible to evaluate impossible to evaluate
Assessment of the trend
impossible to evaluate impossible to evaluate
Legend for 2014 : At 57 hotspots, 38 of a total of 3,042 sampled plants were GM-positive.

Data for the graph: Excel
Source: FOEN
Legend for 2014: 0 of all 620 sampled plants were GM-positive. *In 2019 some 1/3 of the plants were collected using the new sampling concept (weighted random sample).

Data for the graph: Excel
Source: FOEN

Environmental monitoring results show that the percentage of plants that test positively is low (less than 2% on average), although the possibility that genetically modified rapeseed plants could accidentally end up in the environment cannot be entirely ruled out. The high value for 2017 (cf. graph "Hotspots") can be explained by the fact that several samples were collected during that year from an unknown site at which genetically modified rapeseed is frequently found. One major reason for the presence of genetically modified organisms in the environment is that contaminated agricultural products are imported from countries where genetically modified plants are grown. Consequently, the presence of genetically modified plants in Switzerland cannot be prevented entirely. Hence, the cantons continuously apply control measures against genetically modified plants wherever positive test results are found and, in doing so, continue to ensure that no new and lasting populations of plants can be created by genetically modified seeds present in the soil.

This indicator is not assessed. The data primarily depend on external factors such as the volume of GMO-contaminated products imported into Switzerland.


To ensure early recognition of any damage potentially caused by the presence of genetically modified organisms (GMO) in the environment, the FOEN developed an annual monitoring system for genetically modified rapeseed along the SBB railway network. For this purpose, 30 selected 1 km long sections of railway across Switzerland are surveyed for the presence of GM rapeseed. Introduced in 2019, the new sampling concept is based on "weighted" random sampling over the entire SBB freight rail network (3,754 km). It takes into account the rapeseed findings from recent years (since 2014) and ensures that lines with an increased probability of rapeseed occurrence are searched preferentially. The associated increase in "rapeseed hits" (i.e. sections with rapeseed) is around 20%. Since 2020, this new method has replaced the previous one.

In addition to railway monitoring, hot spots, which are sites where GM rapeseed is much likelier to be found (e.g. places where goods are handled, such as warehouses and rail freight stations or transport hubs, food and feed companies, bird feeding sites), are also surveyed for the presence of GM rapeseed.

Last updated on: 15.02.2023

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