PFAS in Pesticides
‘Forever pesticides’
Fidra’s current work focuses on the use of per- and polyfluoroalkyl substances (PFAS) in pesticides, highlighting the serious risks that this practice presents. PFAS in the environment have been shown to accumulate in the tissues of many wildlife species, harm pollinators, damage soil health, and persist in ecosystems for decades — leading to long-term contamination of land and water resources.
Despite these risks, PFAS are amongst some of the most widely used pesticide active substances in the UK [1]. There are currently 27 known PFAS active ingredients in use in UK pesticides, six of which have been identified as highly hazardous [2], [3], [4]. Lack of current regulation is causing farmers to unknowingly pollute their land with harmful forever chemicals, endangering themselves, their consumers, and the environment. With growing concerns over the widespread contamination and public health impacts of PFAS, urgent action is needed to regulate their use in agriculture.
Why are PFAS in pesticides?
PFAS can be intentionally added to pesticides as both ‘active’ and ‘inert’ ingredients. As ‘active’ ingredients, PFAS assist with the actual pest control. Many PFAS in pesticides can directly disrupt biological processes, proving highly toxic towards insects, microbes and plant species [2], [5]. The chemical properties of PFAS can also lead to greater target organisms’ specificity, faster action and prolonged residual activity [6].
Pesticides also include ‘inert’ ingredients or co-formulants, which help the formulation work. PFAS can be added to help with pesticide application, acting as propellants in aerosols, reducing uneven spraying, and facilitating greater penetration into target species [7], [8]. As pesticide inert ingredients are not required to be disclosed by manufactures, PFAS-containing pesticides may be being applied to land without the user’s knowledge. Inert ingredients are assumed to be non-toxic, but research indicates that inert substances in pesticides can also be lethal to pollinators [9].
PFAS may also inadvertently contaminate pesticides through the containers in which they are stored. Many pesticides, like other industrial and household products, are stored in high-density polyethylene (HDPE) containers, which can be lined with PFAS to enhance durability [10]. However, multiple cases of PFAS contamination in pesticides have been reported that are consistent with leaching from these containers [11]. This is a worrying example of how the lack of a group-wide PFAS restriction is leading to the unintentional contamination of our environment with harmful ‘forever chemicals.’
Environmental risks of PFAS in pesticides
PFAS are frequently associated with harmful environmental effects due to their extreme persistence. Because PFAS don’t breakdown, these chemicals continue to travel through the environment and accumulate in ecosystems, meaning their negative impacts can be wide-ranging and long-term. Soil is a major sink for chemicals in the environment, including PFAS from pesticides. When inhabiting contaminated soil, organisms can absorb and accumulate PFAS [12]. PFAS have also been shown to alter microbial activity, leading to a significant increase in pH and modifying growing conditions [13]. Overall, PFAS can alter soil microbial communities and reduce the biodiversity and connectivity of soil bacteria, all of which can impact crop yields[14], [15].
Unhealthy and contaminated soil means unhealthy agricultural ecosystems. PFAS pesticides are not only toxic to the organisms they target, but exposure can impact a wide range of invertebrate species [16]. Existing research consistently reports negative outcomes, with bees being particularly vulnerable to chemical contaminants [17]. PFAS can accumulate in pollen, posing a significant risk to bee species by disrupting hormone regulation [18]. With few ecological studies investigating the direct effects of PFAS exposure, we need a more precautionary approach when considering the chemical cocktails being directly applied to land.
PFAS from pesticides don’t just affect our fields but have an easy pathway to runoff and enter our waterways. The persistence and mobility of PFAS means it is virtually impossible to contain them, with numerous negative outcomes. Research has shown forever chemicals to bioaccumulate in freshwater macro invertebrates and fish species [19] and PFAS have demonstrated toxicity for algae and crustaceans [20]. PFAS in waterways also threaten drinking water supplies, contributing to human exposure and potential health risks.
Health risks of PFAS in pesticides
The negative health effects associated with PFAS are well documented, and their use in pesticides provides yet another pathway for exposure through our food and water supply. Recent research has shown that fruit and vegetables in the UK and across the EU are becoming more and more likely to be contaminated with residues from PFAS pesticides[2] [21]. As PFAS pesticides become increasingly common, analysis reveals that the prevalence of PFAS residues has almost tripled between 2011 and 2021 across the EU. Some samples of strawberries and peaches had contamination rates as high as 37% and 35% respectively. Diet and drinking water are major pathways through which people are exposed to PFAS, with numerous negative health impacts [22], [23]. For example, dietary exposure to PFAS has been connected with adverse effects on the human immune system [24], the liver [25] and other chronic health impacts [26].
TFA
As well as posing risks in their own right, PFAS can break down into smaller molecules that have their own distinctive risks. Trifluoroacetic acid (TFA) is a short chained PFAS that is a common breakdown product of other larger PFAS used in pesticides [27]. TFA is very mobile, allowing it to spread quickly, especially through the water cycle [5], [6]. Left unchecked, environmental concentrations of TFA will continue to rise and there are growing scientific concerns over the impact this may have on human health or environmental processes [28], [29], [30], [31]. TFA is readily absorbed by the body and has been shown to be a reproductive toxicant in mammals [32], and is classified as harmful to aquatic life [33] Research in the EU has found TFA to be widespread in surface water [34], ground water [34], drinking water [29] and even bottled mineral water [35].
Figure 1: TFA belongs to the same subgroup of PFAS as PFOA, one of the most toxic and well known PFAS. TFA is the smallest molecule in this group with the shortest perfluorinated carbon chain.
Our work on PFAS in pesticides
There are currently 27 PFAS active ingredients licenced for use in UK pesticides. In 2024, Fidra investigated PFAS pesticide use in the UK, with a focus on the arable sector. The key findings from this work were as follows:
- PFAS pesticides are used across all agricultural crop sectors in the UK.
- In 2022, PFAS pesticides were sprayed on the equivalent of more than 10.6 million hectares of arable crops.
- PFAS pesticides represented 16% of the most used pesticides within the arable sector in 2022.
- Six PFAS pesticides that were included on the arable sector’s most used pesticides list have significantly increased in use between 2020 and 2022.
It is important to remember that this work only covered PFAS as ‘active’ ingredients. Pesticide products may also contain PFAS as ‘inert’ ingredients, however this information is not currently required to be disclosed by manufacturers.
Removing forever chemicals from pesticides and society
Fidra is calling on the UK Government to align with EU chemical regulation and commit to a universal restriction on PFAS. With over 10,000 PFAS, only with a wide-reaching ban can we prevent further environmental harm via regrettable substitution. A greater variety of PFAS means more uncertainty of their acute environmental effects and gives rise to the potential for more ‘cocktail’ effects – whereby chemical harms are exacerbated when different compounds mix in the environment.
We are also working with farmers to understand the challenges and opportunities in transitioning away from chemical inputs. Our farmer case studies showcase farmer attitudes towards PFAS pesticides, the challenges they are facing and some of the brilliant work they are already doing to reduce pesticide use. Visit our farmer hub for more information.
A call for urgent action
‘Forever chemicals’ threaten both public and environmental health, as well as the long-term productivity of UK agricultural land, with no sustainable solution for remediation. From the widespread pollution of UK rivers to contamination of local wildlife, it is well established that action must urgently be taken to reduce pesticides and wider chemical pollution, as outlined in the UK’s Environmental Improvement Plan, 2023.
We are calling on the UK Government to recognise the significant threat PFAS pesticides presents to public and environmental health and to commit to a group-based restriction on all non-essential uses of PFAS, including use in pesticides. This should be accompanied by effective support for the agricultural sector to transition away from chemical inputs and towards more sustainable practises, such as integrated pest management, wherever possible, and where pesticides are still used, these should come with full transparency of both active and inert ingredients.
Resources
PFAS Active Substances in UK Pesticides
This report investigates the use of PFAS as an active pesticide substance in the UK, with particular focus on the UK arable sector. Pesticide active substances present a direct route for PFAS into the environment, threatening soil health and productivity. PFAS are known to alter soil microbial communities and reduce the biodiversity and connectivity of soil bacteria, all of which can impact crop yields.
Published: July 2024
Author: Fidra
Forever Chemicals in Pesticides Factsheet
Explore key facts about the usage and impacts of PFAS pesticides. Use of PFAS in pesticides provides a direct source of environmental contamination, risking soil health and productivity for future generations.
Published: July 2024
Author: Fidra
PFAS and Pesticides: Europe’s toxic harvest
This report reveals the presence of PFAS as active substances among pesticides used across Europe. Pesticide active substances are currently not included within the proposed European universal PFAS restriction, all the while their use in agriculture is rising.
Published: Nov 2023
Authors: PAN Europe, Generations future
TFA in Drinking Water
TFA is a key degradation product of PFAS pesticides. This report analysed drinking water in Europe (both tap water and bottled water) for the presence of TFA.
Published: July 2024
Authors: PAN EU, Generations Furtures, Global 2000, Mouvement ecologique, Magyar Termeszetvedok Szovetsege, Nature Progres Belgique, Earth Trek, PAN Germany, PAN Netherlands, & Via Pontica.
TFA in Surface and Groundwater
TFA is a key degradation product of PFAS pesticides. This report analysed surface and groundwater samples from ten EU countries for TFA residues and other PFAS.
Published: May 2024
Authors: BUND Friends of the Earth Germany, Earth Trek, Ecologistas en accion, Future Generations, Global 2000, Mouvement ecologique, Swedish Society for Nature Conervation, PAN Europe, PAN Germany, PAN Netherlands, & Via Pontica.
Farmer Case Study: Sustainable farming for healthy soils
Lack of robust regulation means farmers are unknowingly applying harmful substances to their soils, including PFAS ‘forever chemicals’ used in pesticides, and contaminants found in treated sewage sludge or ‘biosolids’.
This case study explores how farmer, Philip Sheane, avoids chemical contamination in farming. After growing concerns over the impacts chemical inputs may have on his health, his livestock, and his soil, Philip began investigating regenerative farming practices.
Published: December 2024
Author: Fidra
Fidra’s Policy Brief
Read our policy brief detailing why we urgently need comprehensive action to prevent further PFAS emissions from pesticides.
References
[1] Fidra, “PFAS Active Substances in UK Pesticides,” Jul. 2024. Accessed: Feb. 05, 2025. [Online]. Available: https://www.fidra.org.uk/download/pfas-in-uk-pesticides/
[2] PAN UK, “‘Forever chemicals’ found in UK food – Pesticide Action Network UK.” Accessed: Jun. 12, 2024. [Online]. Available: https://www.pan-uk.org/pfas-forever-chemicals/
[3] World Health Organization, Food and Agriculture Organization of the United Nations, and Inter-Organization Programme for the Sound Management of Chemicals, The international code of conduct on pesticide management : guidelines on highly hazardous pesticides. 2016.
[4] Pesticide Action Network International, “PAN International List of highly hazardous Pesticides (HHPs) March 2021,” 2021.
[5] Pesticide Action Network Europe, “Licence to Kill: EU guideline to protect insects failed to block harmful pesticides.” Accessed: Feb. 05, 2025. [Online]. Available: https://www.pan-europe.info/press-releases/2024/11/licence-kill-eu-guideline-protect-insects-failed-block-harmful-pesticides
[6] D. A. M. Alexandrino, C. M. R. Almeida, A. P. Mucha, and M. F. Carvalho, “Revisiting pesticide pollution: The case of fluorinated pesticides,” Environmental Pollution, vol. 292, p. 118315, Jan. 2022, doi: 10.1016/J.ENVPOL.2021.118315.
[7] L. G. T Gaines and C. G. Linda T Gaines, “Historical and current usage of per- and polyfluoroalkyl substances (PFAS): A literature review,” Am J Ind Med, vol. 66, no. 5, pp. 353–378, May 2023, doi: 10.1002/AJIM.23362.
[8] N. Donley, C. Cox, K. Bennett, A. M. Temkin, D. Q. Andrews, and O. V. Naidenko, “Forever Pesticides: A Growing Source of PFAS Contamination in the Environment,” Environ Health Perspect, vol. 132, no. 7, Jul. 2024, doi: 10.1289/EHP13954/SUPPL_FILE/EHP13954.S002.CODEANDDATA.ACCO.ZIP.
[9] E. A. Straw, L. J. Thompson, E. Leadbeater, and M. J. F. Brown, “Inert ingredients are understudied, potentially dangerous to bees and deserve more research attention,” Proceedings of the Royal Society B: Biological Sciences, vol. 289, no. 1970, 2022, doi: 10.1098/rspb.2021.2353.
[10] A. A. Rand and S. A. Mabury, “Perfluorinated carboxylic acids in directly fluorinated high-density polyethylene material,” Environ Sci Technol, vol. 45, no. 19, pp. 8053–8059, Oct. 2011, doi: 10.1021/ES1043968/SUPPL_FILE/ES1043968_SI_001.PDF.
[11] N. Donley, C. Cox, K. Bennett, A. M. Temkin, D. Q. Andrews, and O. V. Naidenko, “Forever Pesticides: A Growing Source of PFAS Contamination in the Environment,” Environ Health Perspect, vol. 132, no. 7, Jul. 2024, doi: 10.1289/EHP13954/SUPPL_FILE/EHP13954.S002.CODEANDDATA.ACCO.ZIP.
[12] B. Wen et al., “Bioavailability of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in biosolids-amended soils to earthworms (Eisenia fetida),” Chemosphere, vol. 118, no. 1, pp. 361–366, Jan. 2015, doi: 10.1016/J.CHEMOSPHERE.2014.08.009.
[13] B. Xu, G. Yang, A. Lehmann, S. Riedel, and M. C. Rillig, “Effects of perfluoroalkyl and polyfluoroalkyl substances (PFAS) on soil structure and function,” Soil Ecology Letters, vol. 5, no. 1, pp. 108–117, Mar. 2023, doi: 10.1007/S42832-022-0143-5/METRICS.
[14] L. Cao, W. Xu, Z. Wan, G. Li, and F. Zhang, “Occurrence of PFASs and its effect on soil bacteria at a fire-training area using PFOS-restricted aqueous film-forming foams,” iScience, vol. 25, no. 4, Apr. 2022, doi: 10.1016/j.isci.2022.104084.
[15] J. yi Wu, F. ge Ding, Z. wei Shen, Z. lin Hua, and L. Gu, “Linking microbiomes with per- and poly-fluoroalkyl substances (PFASs) in soil ecosystems: Microbial community assembly, stability, and trophic phylosymbiosis,” Chemosphere, vol. 305, p. 135403, Oct. 2022, doi: 10.1016/J.CHEMOSPHERE.2022.135403.
[16] Bug Life, “‘Forever chemicals’ detected in UK food, prompting concerns regarding impact on human health.” Accessed: Feb. 05, 2025. [Online]. Available: https://www.buglife.org.uk/news/forever-chemicals-detected-in-uk-food-prompting-concerns-regarding-impact-on-human-health/
[17] K. S. Traynor et al., “Pesticides in honey bee colonies: Establishing a baseline for real world exposure over seven years in the USA,” Environmental Pollution, vol. 279, p. 116566, Jun. 2021, doi: 10.1016/J.ENVPOL.2021.116566.
[18] T. Wright, M. Crompton, D. Bishop, G. Currell, L. Suwal, and B. D. Turner, “Phytoremediation evaluation of forever chemicals using hemp (Cannabis sativa L.): Pollen bioaccumulation and the risk to bees,” Chemosphere, vol. 370, p. 143859, Feb. 2025, doi: 10.1016/J.CHEMOSPHERE.2024.143859.
[19] M. Chen, Q. Wang, G. Shan, L. Zhu, L. Yang, and M. Liu, “Occurrence, partitioning and bioaccumulation of emerging and legacy per- and polyfluoroalkyl substances in Taihu Lake, China,” Science of The Total Environment, vol. 634, pp. 251–259, Sep. 2018, doi: 10.1016/J.SCITOTENV.2018.03.301.
[20] E. Pietropoli et al., “Comparative toxicity assessment of alternative versus legacy PFAS: Implications for two primary trophic levels in freshwater ecosystems,” J Hazard Mater, vol. 477, p. 135269, Sep. 2024, doi: 10.1016/J.JHAZMAT.2024.135269.
[21] PAN Europe et al., “TOXIC HARVEST: The rise of forever pesticides in fruit and vegetables in Europe,” 2024.
[22] S. Poothong, E. Papadopoulou, J. A. Padilla-Sánchez, C. Thomsen, and L. S. Haug, “Multiple pathways of human exposure to poly- and perfluoroalkyl substances (PFASs): From external exposure to human blood,” Environ Int, vol. 134, p. 105244, Jan. 2020, doi: 10.1016/J.ENVINT.2019.105244.
[23] J. L. Domingo and M. Nadal, “Per- and Polyfluoroalkyl Substances (PFASs) in Food and Human Dietary Intake: A Review of the Recent Scientific Literature,” J Agric Food Chem, vol. 65, no. 3, pp. 533–543, Jan. 2017, doi: 10.1021/ACS.JAFC.6B04683.
[24] V. Ehrlich et al., “Consideration of pathways for immunotoxicity of per- and polyfluoroalkyl substances (PFAS),” Environmental Health 2023 22:1, vol. 22, no. 1, pp. 1–47, Feb. 2023, doi: 10.1186/S12940-022-00958-5.
[25] J. Zhang, L. Hu, and H. Xu, “Dietary exposure to per- and polyfluoroalkyl substances: Potential health impacts on human liver,” Science of The Total Environment, vol. 907, p. 167945, Jan. 2024, doi: 10.1016/J.SCITOTENV.2023.167945.
[26] K. Roth, Z. Imran, W. Liu, and M. C. Petriello, “Diet as an Exposure Source and Mediator of Per- and Polyfluoroalkyl Substance (PFAS) Toxicity,” Frontiers in Toxicology, vol. 2, p. 601149, Dec. 2020, doi: 10.3389/FTOX.2020.601149/BIBTEX.
[27] H. P. H. Arp, A. Gredelj, J. Glüge, M. Scheringer, and I. T. Cousins, “The Global Threat from the Irreversible Accumulation of Trifluoroacetic Acid (TFA),” Environ Sci Technol, vol. 58, no. 45, pp. 19925–19935, Nov. 2024, doi: 10.1021/acs.est.4c06189.
[28] BUND Friends of the Earth Germany et al., “TFA in Water: Dirty PFAS Legacy Under the Radar,” 2024.
[29] PAN EU et al., “TFA The Forever Chemical in the Water We Drink Only a rapid ban on PFAS pesticides and F-gases can save our water,” 2024.
[30] F. Freeling and M. K. Björnsdotter, “Assessing the environmental occurrence of the anthropogenic contaminant trifluoroacetic acid (TFA),” Jun. 01, 2023, Elsevier B.V. doi: 10.1016/j.cogsc.2023.100807.
[31] F. Freeling, M. Scheurer, J. Koschorreck, G. Hoffmann, T. A. Ternes, and K. Nödler, “Levels and Temporal Trends of Trifluoroacetate (TFA) in Archived Plants: Evidence for Increasing Emissions of Gaseous TFA Precursors over the Last Decades,” Environ Sci Technol Lett, vol. 9, no. 5, 2022, doi: 10.1021/acs.estlett.2c00164.
[32] P. H. H. Arp, A. Gredelj, J. Glü, M. Scheringer, and I. T. Cousins, “The Global Threat from the Irreversible Accumulation of Trifluoroacetic Acid (TFA),” Environ Sci Technol, vol. 58, no. 45, pp. 19925–19935, Nov. 2024, doi: 10.1021/ACS.EST.4C06189.
[33] “Datenbank des C&L-Verzeichnisses.” Accessed: Feb. 13, 2025. [Online]. Available: https://echa.europa.eu/de/information-on-chemicals/cl-inventory-database/-/discli/details/47316
[34] BUND Friends of the Earth Germany et al., “TFA in Water: Dirty PFAS Legacy Under the Radar,” 2024.
[35] Pesticide Action Network Europe, “TFA: The ‘Forever Chemical’ in European Mineral Waters.” Accessed: Feb. 03, 2025. [Online].