Persistent, Mobile and Toxic Chemicals

The persistent, mobile and toxic (PMT) — and very persistent and very mobile (vPvM) — chemicals easily enter the water cycle, including drinking water, and spread over long distances. If emissions continue, the concentrations in the environment will increase over time. Environmental contamination with these chemicals is difficult to reverse as commonly used adsorption techniques cannot capture them. In the Classification, Labelling, and Packaging (CLP) regulation, it is stated that “any effects from this exposure are unpredictable in the long-term”.

The fact that persistent and mobile chemicals can transport through soils and contaminate water resources has been known for a long time. Mobility through soils has been in focus in pesticide risk assessment as well as in the Globally Harmonised System of Classification and Labelling of Chemicals (GHS). The combination of the intrinsic properties of persistence and mobility leads to potentially uncontrollable risks, requiring similar risk management approaches to those for persistent, bioaccumulative, and toxic (PBT) chemicals. This has been argued for many years, not the least by Germany's central environmental authority (UBA). Since 2023, PMT and vPvM have been designated as hazard classes in the EU CLP Regulation.

Many PMT chemicals have already been found to pollute water resources. TFA (trifluoracetate) is one such example. It is found in drinking waters across the world and has a toxicological profile that is increasingly worrisome as it is now proposed to be classified as toxic to reproduction. Other examples include benzotriazoles, melamine, cyanuric acid, and methenamine, which have been found in treated drinking water. For cyanuric acid, for example, human biomonitoring data suggest that exposure already gives rise to toxicity, a strong indication that it is time to act now to reduce exposure to the PMT/vPvM chemicals.

For TFA and other PFAS chemicals, estimates have been made to indicate the costs that society can expect if emissions are not halted. The Forever Lobbying project calculated the costs to “around €100 billion every year to remove short-chain and ultrashort-chain PFAS, even partially, from the environment and to destroy them”. Over 20 years, it is estimated to cost more than two trillion euros, which is more than 10% of Europe’s GDP or more than twice the total annual sales of the European chemical industry. The costs of pollution of all PMT/vPvM could reach insurmountable levels if emissions are not stopped.

ChemSec has now added PMT/vPvM substances to the SIN List twice. First in 2019, using the PMT criteria as developed by UBA. And now in 2025, using the new CLP guidance. The SIN List now contains 53 PMT/vPvM entries, carefully selected from starting lists of hundreds of persistent and mobile chemicals as identified in the REACH registration database. The assessment process was led both times by acknowledged experts in the field. Chemicals were identified as PMT or vPvM based on a structured weight-of-evidence approach and prioritised based on the urgency of action.The 18 PMT/vPvM entries added to the SIN List in 2025 are: