It is found in almost 80 percent of the herbicides used worldwide: the pesticide active ingredient glyphosate. It was released in 1974 under the name Roundup. Many hobby gardeners use it to control weeds in paved areas. But there is now a statutory ban on glyphosate for them. On the other hand, the active ingredient can still be used in farmland around the world.

The WHO Agency for Research on Cancer criticizes glyphosate. He sees clear evidence of a “possibly carcinogenic effect” of the active ingredient. But manufacturers conclude that it is harmless.

Plant protection products containing glyphosate are permitted throughout Europe until 31 December 2023. Does this close the deprecation of glyphosate? NObecause the European Food Safety Authority, EFSA for short, wants to re-evaluate the pesticide active substance by mid-2023.

As the EU review process continues, a study on insect tolerance of glyphosate-based herbicides, GbH for short, has been published by the Swiss Federal Institute of Technology (ETH) Zurich and the Federal Nature Conservation Agency (BfN). . Laced larvae were used as test objects. It was sprayed on insect eggs and the larvae were found to ingest glyphosate. As a result, the animals did not develop further and died.

Another study result: GbH is toxic even to insects if the concentration is well below the allowable spray amount. “The danger posed by the direct insecticidal action of GbH after oral ingestion is of paramount importance for environmental safety and reveals a gap in the official risk assessment,” says Angelika Hilbeck of ETH Zurich. This gap needs to be closed immediately.

For BfN, the results of the study are cause for concern. Other insects can also be damaged and killed by GbH. “If weeds are cleared with glyphosate over a large area, species deprived of their livelihoods will inevitably disappear,” says BfN President Sabine Riewenherm.

According to Riewenherm, cultivated plants that are then left alone in the field cannot replace natural plant and grass abundance in terms of their importance for biodiversity.

Regardless of the study results, Deutsche Bahn announced on 12 March 2023 that it will completely stop using the controversial herbicide starting this year. In the future, weeds on the railway lines will be removed with mowers and environmentally friendly pelargonic acid. Pelargonic acid is an active ingredient of natural origin obtained from rapeseed oil.

“By 2020, Deutsche Bahn had reduced the use of glyphosate by more than half compared to 2018. Among other things, modern camera systems for plant recognition contributed to precision application and thus to the reduction of glyphosate,” says Franziska Hentschke, Deutsche’s environmental spokesperson. bahn.

Environmental umbrella organization Deutscher Naturschutzring (DNR) welcomes the decision. “With the phasing out of glyphosate, DB makes an important statement in favor of moving away from chemical-synthetic pesticides,” says DNR Chairman Kai Niebert.

However, more environmentally friendly methods of vegetation control will need to be further encouraged to end the discussion about a possible reapproval of glyphosate after 2023, according to environmental and nature associations.

Christine Elsner is the editor of the ZDF environmental department.