Planet

TFA, PFAS. From pesticides to drinking water

October 17, 2024

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A compound belonging to the PFAS family of toxic chemicals – trifluoroacetic acid, TFA – is being carried by pesticides into drinking water across Europe.

A brief summary of the results of the analyses conducted on rivers, lakes and aquifers by members of Pesticide Action Network (PAN) Europe and the RTS participatory survey in Switzerland (1,2).

Table of Contents

1) PFAS, ‘forever chemicals’

A large group of chemical compounds, the per- and polyfluoroalkyl substances (PFAS), is characterized by several aspects:

-wide use in a variety of industrial products. Plant protection products (i.e. pesticides, herbicides), fire-fighting foams, objects and materials in contact with food (e.g. food packaging, including disposable ones, non-stick coatings for pots and pans), waterproof fabrics;

-extraordinary high resistance properties (to heat, water and oily substances) and mobility. The molecules of the substances of the PFAS group, not only do not degrade, but also leach into the environment to accumulate in tissues (including human and animal), and are in fact known as ‘forever chemicals’;

-carcinogenic action, already confirmed by IARC (International Agency for Research on Cancer), as well as endocrine interference. (3) With significant levels of exposure in the population, of particular concern in children. (4)

2) PFAS, TFA and pesticides

Pesticides, herbicides and fungicides (i.e. chlorothalonil) that contain PFAS are considered to be the primary cause of water contamination with TFA in rural areas. Followed by refrigerants (fluorinated greenhouse gases, F-gases), wastewater treatment and industrial pollution.

TFA, nevertheless, is a PFAS that has received little or no attention in water analysis and in particular in drinking water in some Member States, unlike other PFAS listed in the Drinking Water Directive (EU) No 2020/2184. (5)

3) TFA and other PFAS in drinking water in the EU, PAN Europe analyses

PAN Europe, conducted an exploratory survey in the European Union, with analyses on drinking water (tap) and mineral water. (6) The results, in summary:

-TFA were detected in 34 of 36 European tap water samples (94%) from eleven EU countries and in 12 of 19 bottled mineral and spring waters (63%);

-TFA detected in drinking water range from ‘undetectable’ (therefore below the Limit of Detection of 20 ng/L) up to 4.100 ng/L (in Northern Austria), with an average of 740 ng/L;

-TFA levels in mineral and spring waters range from ‘undetectable’ to 3.200 ng/L, with an average of 278 ng/L;

-analysis of 24 further PFAS in 4 mixed samples confirms the prevalence of TFA (> 98%) in drinking and mineral water. (1)

4) TFA in drinking water in Switzerland, report from cantonal laboratories

The report on drinking water analyses conducted in Switzerland by cantonal laboratories (2023) in turn reveals the omnipresence of TFA, detected in 99% of the samples analysed. (7) In particular:

-the analyses were conducted in spring 2023 on 564 drinking water samples, with a territorial distribution expressing approximately 71% of the Swiss population’s supply;

-TFA was detected in 560 out of 564 samples, in significant quantities (0,765 μg/L). These quantities are much higher than those of the other most commonly detected PFAS (within 0,01 μg/l);

– the thresold values for three PFAS present in the Ordinance of the Federal Department of the Interior (CH) on drinking water and on the water of swimming pools and showers accessible to the public are set between 0,3 and 0,5 µg/L; (8)

– Germany has instead decided to set an indicative threshold value 200 times higher (60 µg/l). For the time being, the Confederation has not issued specific regulations or recommendations on TFA.

5) TFA, what toxicity?

EFSA had expressed its opinion on the TFA toxicity, back in 2014, essentially based on a 2007 study on rats conducted by Bayer. (9) Few toxicological studies were available at the time, despite the widespread use of PFAS-degrading pesticides.

EFSA’s estimate of the TDI (Tolerable Daily Intake) of TFA for humans, starting from the NOAEL (No Observed Adverse Effects Level) on animals, however seems to neglect the size of the UF (Uncertainty Factors) indicated by WHO, linked precisely to the lack of studies (1,10).

A further study on rabbits, conducted by Bayer and Solvay, revealed acute malformations in fetuses of pregnant animals whom TFA was administered at all ages. (11) It was thus revealed that it was impossible to apply a NOAEL and that it was necessary to define a LOAEL (Lowest Observed Adverse Effect Level) instead.

5.1) ‘No threshold’ approach

‘No threshold chemicals’ are those substances for which no level of exposure can be considered safe. Genotoxic substances (i.e. capable of causing damage to DNA) and carcinogenic, but also endocrine disruptors that can cause reproductive disorders, hormone-dependent tumors, thyroid function disorders, metabolic, developmental, immune, neurological and behavioral disorders.

The exposure at low levels of these chemicals during early life can lead to permanent adverse effects, exposing pregnant women, infants and young children to very serious health risks. And precisely because it is not possible to establish thresholds of adverse effects (LOAELs) with certainty, all appropriate measures should be taken to keep human exposure to these substances to the lowest possible levels.

6) Rules under discussion

The European Union has not yet defined a uniform threshold for TFA in surface, ground or drinking water. And therefore:

-the application, starting from 1 January 2026, of a limit value in drinking water equal to 500 ng/L of ‘total PFAS’ which should also include TFA is being discussed;

-the ongoing revision of the Water Framework Directive 2000/60/EC in any case opens the opportunity to establish quality standards (=limit values) for TFA in natural water bodies.

7) European scenario

Half of the drinking water samples analysed in exceed the limit value of 500 ng/L for ‘total PFAS’, if TFAs are included in this parameter from 2026. In this case, Member States will have to make billions of euros in investments to secure water supplies.

Drinking water filtration with activated carbon, effective with residues of other pesticides, does not work with TFA. The water should therefore be treated with the much more expensive technique of osmosis.

Drinking water subjected to such an expensive, non-ecological and high-tech purification process would still be depleted of its natural components. This water would therefore have to be remineralized by distributors, with a high energy expenditure, before being introduced into the water circuits.

8) Conclusions

The TFA in drinking water continues to increase every day due to the use of pesticides with PFAS and fluorinated gases. To ensure that European citizens can still drink their drinking water safely in the coming decades, PAN Europe recommends urgently taking effective measures, such as:

-immediate ban on PFAS pesticides

– immediate ban on fluorinated gases

-general restriction on PFAS in the REACH regulation

-setting a maximum limit for TFA in the Drinking Water Directive

-definition of quality standards for TFAs in the Water Framework Directive

– support for farmers in replacing the use of PFAS pesticides, which also remain in fruit and vegetables as has been seen, (12) with other forms of crop protection, possibly free of synthetic chemicals

-application of the ‘polluter pays’ principle wherever it is necessary to purify water due to chemical contamination.

Dario Dongo

Footnotes

(1) TFA: The Forever Chemical in the Water We Drink. PAN (Pesticides Action Network) Europe. Reports. 10.7.24 https://t.ly/x5Q_-

(2) Le TFA, a polluant often ignored in the eau du robinet. RTS. 30.9.24 https://t.ly/FPUmR

(3) Marta Strinati. PFAS substances are carcinogenic, IARC confirms. GIFT (Great Italian Food Trade). 3.12.23

(4) Sabrina Bergamini. PFAS and toxic substances, the pollution that threatens children’s health. Egalité. 11.10.24

(5) Dario Dongo. PFAS and microplastics, EU guidelines for monitoring and analysis of drinking water. GIFT (Great Italian Food Trade). 30.8.24

(6) PAN Europe performed the analyses by HPLC-MS-MS, with limit of quantification (LOQ) equal to 50 ng/L for trifluoroacetate (TFA), 1 ng/L for the 20 PFAS regulated by the Drinking Waters Directive, 2 ng/L for perfluoropropionate (PFPrA), 1 ng/L for perfluoropropane sulfonate (PFPrS), 50 ng/L for PFAS (PFPrS)

(7) Verband der Kantonschemiker der Schweiz. Auswertung VKCS-Campagne PFAS in Trinkwasser 2023. 12.10.23 https://t.ly/1p40X

(8) Swiss Confederation. Ordinance of the FDHA on drinking water and water for swimming pools and showers accessible to the public (OPPD). 16.12.16 https://t.ly/L8o5Z

(9) EFSA (2014). Reasoned opinion on the setting of MRLs for saflufenacil in various crops, considering the risk related to the metabolite trifluoroacetic acid (TFA). https://doi.org/10.2903/j.efsa.2014.3585

(10) WHO (1994). Environmental Health Criteria 170. Assessing human health risk of chemicals: derivation of guidance values for health-based exposure limits https://t.ly/6J5b9

(11) See ‘Trifluoroacetic acid. Developmental toxicity, teratogenicity’ on ECHA database https://t.ly/CsQ2t

(12) Marta Strinati. PFAS in non-organic fruits and vegetables through pesticides. PAN Europe study. GIFT (Great Italian Food Trade). 26.2.24