The issue has come before the parliament following a question regarding Marc Goergen (Piratepartei) on ‘forever chemicals’ – those persistent chemicals that accumulate in the environment and in the human body. He refers to ‘extremely harmful’ compounds that are present ‘almost everywhere’ and have already been detected in water and food.

In her reply, the minister for agriculture, Martine Hansen (CSV), and the minister for the environment, Serge Wilmes (CSV), provide a clear picture on paper. No PFAS have been detected in the Luxembourg mineral waters tested to date. However, another compound, TFA, is present in ‘four of the six springs’ used to produce mineral or spring water. The concentrations observed “do not pose a risk from a food safety perspective”, the authorities assure us.

This distinction between PFAS and TFA now shapes the debate. PFAS encompass thousands of fluorinated substances known for their persistence. TFA (trifluoroacetic acid) is considered the smallest and one of the most problematic and concerning PFAS, due to its extreme ubiquity, its virtually eternal persistence and its very high mobility in water. In official monitoring schemes, it is measured separately, with its own specific parameters.

The TFA is on the rise

This distinction is not merely a technicality. In practice, the authorities never measure ‘all PFAS’, but rather a limited list of substances, using methods that do not always detect the smallest molecules. TFA, which is highly mobile and chemically distinct, falls outside standard protocols and requires specific analyses. The result: for years, monitoring of PFAS in drinking water was carried out without it. It is only recently that it has been included in testing, but as a separate parameter.

In Luxembourg, PFAS have been monitored in drinking water for several years, with no clear trend and the “vast majority of samples” showing no detectable traces. TFA, on the other hand, has only been analysed since late 2023, with authorities already noting an “upward trend”. However, no figures have been provided. Neither measured levels, nor precise trends, nor comparisons with any thresholds.

This silence stands in contrast to the situation in other countries. In France, national campaigns publish estimates of the scale of the problem and highlight the widespread presence of TFA in drinking water. In Belgium, too, official studies point to widespread and well-documented contamination. In Luxembourg, the presence of TFA has been confirmed and the trend noted, but the data remains unavailable.

Unnamed brands

In this context, the government’s stance raises questions. Despite the confirmed presence of TFA in several sources, the authorities refuse to disclose the names of the brands concerned. “There is no need to disclose specific information,” states the official response, citing the European regulatory framework. The strategy focuses on prevention rather than treatment. This is because removing these substances remains complex and costly. For TFA, only reverse osmosis would allow for effective treatment, with a “significant” impact on the price of water and the environment.

Behind the health assurances, a divide is emerging. The molecules have been identified and their presence acknowledged, but the figures are lacking. And as TFA establishes itself as the primary indicator of contamination, the issue is no longer just one of thresholds, but of access to data.