Denmark investigates rising sales of suspected PFAS pesticide

Sales in Denmark of the insecticide ingredient lambda-cyhalothrin, suspected of forming the persistent PFAS compound TFA, have risen since 2015, DR reports, citing the Ministry of Environment. Products containing the ingredient remain approved for sale and use in Denmark.

The Danish Environmental Protection Agency will investigate lambda-cyhalothrin and four other PFAS substances still permitted in the country. Environment Minister Maria Reumert Gjerding said the government was prepared to ban products containing lambda-cyhalothrin if research showed they threatened groundwater and drinking water.

“If research shows what we fear, namely that these substances form the persistent chemical TFA to an extent that threatens our groundwater and drinking water, we will ban products with lambda-cyhalothrin,” Gjerding said.

In 2024, products containing a total of 3,326 kilograms of lambda-cyhalothrin were sold in Denmark. The Ministry of Environment said sales had increased since 2015.

The Danish Environmental Protection Agency has given the geological data centre GEUS 1.8 million kroner for a research project examining whether the five substances form TFA at levels that threaten groundwater and drinking water. The study will also determine whether there are grounds to withdraw approval for their use.

While the research is under way, the minister has asked her ministry to assess the possibility of banning pesticides containing the five active substances under the European Union’s precautionary principle.

TFA is not used as a pesticide itself. It can form when certain fluorinated pesticides break down in soil and the environment. The European Chemicals Agency updated its assessment of TFA in spring 2026 and now considers it harmful to human foetuses and reproductive capacity.

TFA was detected in 902 drinking-water boreholes in Denmark between 2021 and 2024, representing 40 per cent of the boreholes tested, according to the Ministry of Environment. The Danish Environmental Protection Agency said current TFA levels in drinking-water boreholes do not pose a risk to people.

In 2025, the agency withdrew 33 pesticides after studies documented that they broke down into TFA above the threshold value. To regulate substances under pesticide rules, including potentially withdrawing approval, it must be documented that they break down into TFA and that this occurs at levels exceeding the applicable thresholds.

The government has previously announced plans for a national pesticide-spraying ban in vulnerable groundwater-forming areas. “Danes must be confident that the water coming from their taps is clean, both today and in the future,” Gjerding said.