Home Care Topics
The Home Care department within IKW provides competent answers to questions concerning hygiene, washing and cleaning.
Safety
Statement of IKW Department Home Care on the degradation of phosphonates
From the perspective of IKW, there is no risk to humans or the environment from the formation of trace amounts of glyphosate in wastewater treatment plants. The phosphonate DTPMP, used as an ingredient in detergents, is only present at very low concentrations in wastewater treatment plants. Under realistic conditions, this does not result in a significant amount of glyphosate.
Background:
On March 11, 2024, the journal Spektrum der Wissenschaft[1] and Deutschlandfunk[2] reported on the pre-print of the findings published by the research group of Professor Dr. Carolin Huhn from the University of Tübingen. The group hypothesized that the herbicide glyphosate could form in wastewater treatment plants from phosphonates such as diethylenetriamine penta(methylene phosphonic acid) (DTPMP), which are ingredients in certain detergents. This study was officially published in the journal Water Research on July 23, 2024.
In response, a member company of IKW reviewed Professor Huhn’s hypothesis by reproducing the experiments using its own test program, based on the information available at that time. DTPMP was combined with sewage sludge and glyphosate formation was not detected in any of the samples.
On March 18 and 19, 2025 Spektrum der Wissenschaft[3] and Deutschlandfunk[4] again reported on the University of Tübingen’s research project, as the group had published new data. In a radio interview, Professor Dr. Carolin Huhn stated:
‘We have clearly demonstrated the possibility of glyphosate formation [from phosphonate DTPMP]. To date, we have only conducted a small laboratory experiment. This means that we need to replicate the dynamics that actually occur in a wastewater treatment plant. We are not there yet. However, we have clearly shown that it can form under the conditions found in treatment plants. And from other studies – including our own – we now know for sure that DTPMP does reach wastewater treatment plants.’
This group succeeded in using sophisticated analytics to detect the formation of minimal amounts of glyphosate from DTPMP. The transformations observed in the experiments with manganese oxides and sewage sludge were minimal. The modelling calculations of Professor Huhn resulted in theoretical environmental concentrations that were significantly lower than the trace levels measured in the surface waters. Therefore, it is assumed that the contribution of the conversion of DTPMP to glyphosate is minimal, in contrast to the glyphosate levels detected in the surface waters.
Professor Dr. Marion Martienssen from the University of Technology Cottbus-Senftenberg in Brandenburg has been researching the degradation of phosphonates in nature for several years. She also found no evidence that significant amounts of glyphosate can be formed from DTPMP in wastewater treatment plants.
Even Professor Dr. Carolin Huhn stated: ‘The biggest question is, can we explain this quantitatively?’ and ‘We still need to explain these amounts.’ The article in Spektrum der Wissenschaft also noted that Huhn’s team attempted to estimate the amount of glyphosate formed annually in German wastewater treatment plants from DTPMP and possibly other amino polyphosphonates based on their experiments. However, the scientist acknowledges that further investigations are needed for a comprehensive assessment.’
Surface waters in the EU and USA have been monitored for decades, including glyphosate concentrations. These measurements show that glyphosate levels do not increase over time and pose no environmental concerns as the values remain far below the threshold for potential negative environmental effects.
IKW closely monitors publications and media reports and updates this statement as new findings become available.
Background information on phosphonates such as DTPMP:
Phosphonates are used in detergents and cleaning agents as stabilizers for enzymes and bleaching agents, as well as in water softeners. They contribute to improved washing performance and stain removal even at low temperatures. In 2024, IKW member companies used less than 710 tonnes of DTPMP.
This statement is also available in the original German version.
Current status: June 13, 2025
[1] „Glyphosat entsteht womöglich aus Waschmittel“
[2] „Woher das Glyphosat in den Flüssen stammt“
[3] Kläranlagen wandeln Waschmittelzusätze in Glyphosat um - Spektrum der Wissenschaft