13
Mar
Study Shows Widely Used Weed Killer To Contain PFAS, Further Threatening Health and the Environment
(Beyond Pesticides, March 13, 2026) In a press release on March 10, 2026, Public Employees for Environmental Responsibility (PEER) cites independent test data on the herbicide indaziflam with detections of per- and poly-fluoroalkyl substances (PFAS), the “forever chemicals†known for significant toxicity at low level exposure and high persistence. The product, Rejuvra™, is produced by Envu (a former division of Bayer) and “is being sprayed and considered for use across millions of acres of Bureau of Land Management (BLM) and US Forest Service land.†Scientific literature connects indaziflam and PFAS with adverse effects to human, soil, and biodiversity health, raising serious concerns about their wide use in agriculture and general land management of lawns, parks, playing fields, ornamentals, fence lines, rights-of-way, rangeland, open space, and Christmas trees.
Background
As a pre-emergent weed killer used to kill annual grasses and unwanted broadleaf plants, the fluoroalkyltriazine herbicide is broadly labeled for use in residential areas, commercial ornamental and sod production, forestry, and mostly orchard crops. While indaziflam is considered a “selective†herbicide, it actually kills and prevents germination of a wide range of broad-leaved plants and grasses and comes close to being a soil sterilant.  Since the chemical is subject to drift and movement off the target site, it can kill annual native plants that provide important ecosystem services for pollinators and wildlife. Documented health and environmental effects of indaziflam include genotoxicity/DNA damage, endocrine disruption, neurotoxicity, kidney and liver damage, birth/developmental effects, leaching, and acute and chronic toxicity to aquatic organisms, among others. (See here, here, and here.)
The classification of PFAS encompasses a large group of chemicals, with a definition that the U.S. Environmental Protection Agency (EPA) eschews. A large number of scientists and the Organisation for Economic Co-operation and Development (OECD) classify compounds with one fully fluorinated carbon atom as PFAS, which are not accurately captured in EPA’s risk assessments. A wide body of science on the adverse health and environmental effects of PFAS exists, as these synthetic chemicals have become ubiquitous in nature, wildlife, and humans, as demonstrated by biomonitoring studies. Research, documented in a literature review in Environmental Science & Technology and additional articles, highlights the importance of a universal, cohesive definition of PFAS that incorporates all fluorinated compounds, including the long carbon chain PFOA (perfluorooactanoic acid) and PFOS (perfluorooctanesulfonic acid), as well as the ultrashort-chain perfluoroalkyl acids (PFAAs).
Both long and short chain PFAS’ adverse effects include, but are not limited to, cancer, endocrine-disrupting effects, and immune system damage. The multitude of sources of PFAS and various exposure routes lead to widespread contamination of the environment and organisms. PFAS use in agriculture represents a large source of poisoning and contamination because of their wide application as pesticide active ingredients, use in the plastic containers that pesticides are stored in, and as surfactants in pesticide products. Additionally, PFAS are used in many other plastic storage containers and food packaging, personal care products, nonstick cookware, cleaning supplies, treated clothing, firefighting foam, and machinery and equipment used in manufacturing—all of which contaminate food, water, soil, and the air.  (See Daily News here.)
Product Testing Results
In testing Rejuvraâ„¢, PEER finds the presence of multiple PFAS in all twelve samples, including PFHxS (perfluorohexanesulfonic acid) and PFHxA (perfluorohexanoic acid). PFBS (perfluorobutanesulfonic acid) and PFOS were also detected in many of the samples. (See the full lab reports here, here, and here.)
The press release notes: “‘The discovery of toxic chemicals in a product intended for landscape-level use should set off alarm bells,’ said Chandra Rosenthal, PEER Public Lands Advocate. ‘Our public lands should not be exposed to chemicals whose impacts remain unknown and that will persist in the environment indefinitely.’â€
On the product label itself, it is listed that indaziflam is the only active ingredient, making up 19.05% of the mixture, with the other 80.95% as “Other Ingredients†or “inert ingredients†that are not disclosed on product labels but can have adverse biological and chemical effects. EPA interprets the federal pesticide law, the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), to allow secrecy of all inert or other ingredients—regardless of toxicity, except for highest toxicity category above a designated percentage of the product—in pesticide products that the manufacturer claims are not included in the formulation as the “active†chemical ingredient to attack the target pest. Active ingredients are mostly a small fraction of the total formulation.
PEER writes: “Manufacturers are not required to disclose the inert ingredients in pesticides, which can make up to 95% of the product and may include PFAS. The detection of PFAS in Rejuvra reinforces the need for full chemical disclosure of all ingredients in pesticides.â€
While not detailing all of the human health risks that independent scientific literature documents for indaziflam, the label highlights some of the environmental hazards. “The product label warns that Indaziflam can contaminate surface waters via runoff and is toxic to fish, vertebrates, and aquatic plants,†PEER notes. “This is a serious concern, given the extensive network of streams, wetlands, and riparian corridors across public lands.â€
The presence of PFAS in this herbicide product is alarming to scientists and public health and environmental advocates, not only in terms of the lack of disclosure but because of the increased risks associated with chemical mixtures within products and pesticide mixtures as they are encountered in the environment, which can have additive or synergistic effects. This heightened toxicity is not accounted for in individual active ingredient assessments, further threatening health and the environment.
Previous Research
Both indaziflam and PFAS have been covered in previous Daily News. One study published in Science of the Total Environment, entitled “The silence of the clams: Forestry registered pesticides as multiple stressors on soft-shell clams,†finds that chronic exposure to pesticides, including indaziflam, used in conventional forestry operations runoff harm soft shell clams. Rather than focusing on the impact of a single chemical, researchers analyzed the combined effects of several pesticides. “This is an important data gap to fill as research on these compounds’ toxicity typically focuses on individual compound effects at high concentrations to determine lethality, which while necessary for understanding compound toxicity, can miss sublethal effects that can have long term impacts on these systems,†said lead author Allie Tissot, PhD, previously of Portland State University and currently with the Oregon Department of Agriculture. (See Daily News here.)
Another article highlights how indaziflam causes broadscale devastating ecological and health effects. Use of the herbicide indaziflam is an example of the ineffectiveness of management based on herbicides. The action on seedlings is long-lasting, thus inhibiting the growth and establishment of a resilient plant community that is resistant to invasion. Given its persistence and widespread effects and the extent of the damage it causes to native soil seed banks and plant biodiversity, indaziflam could contribute to the decline of ecosystems where it is applied, similar to the cascading impacts of the systemic insecticides, such as fipronil and the neonicotinoids, on animals. The impacts of indaziflam could be even greater than insecticides since plants are the foundation of all living systems. Building resilience and resistance into a plant community requires working with succession, which requires the growth of some annuals, in preparation for the longer term community of mostly perennials—contrary to the approach of killing all “weeds.â€
From epigenetic to immunotoxic effects, there is a wide range of health implications with PFAS exposure. Because of their ubiquitous use, studies report that PFAS compounds are detectable in infants, children, and pregnant women. Furthermore, pregnant women can readily transfer compounds to the developing fetus through the placenta. PFAS residues are persistent in food and drinking water, with over six million U.S. residents regularly encountering drinking water with PFAS levels above the EPA health advisory of 70 ng/L. Therefore, PFAS are detectable in almost all of the U.S. population—disproportionately afflicting people of color communities—and have implications for human health. (See Daily News here.)
A previous Daily News article, titled “Science on “Forever Chemicals†(PFAS) as Pesticide Ingredients and Contaminants Documented,” shows how and to what extent PFAS can be introduced into pesticide products, and how this impacts health and the environment. The findings are gleaned from public records requests to state and federal agencies in the U. S. and Canada, as well as from publicly accessible databases discussed in the commentary Forever Pesticides: A Growing Source of PFAS Contamination in the Environment. According to the authors: “The biggest contributor to PFAS in pesticide products was active ingredients and their degradates [chemical breakdown products]. Nearly a quarter of all U.S. conventional pesticide active ingredients were organofluorines and 14% were PFAS, and for active ingredients approved in the last 10 y[ears], this had increased to 61% organofluorines and 30% PFAS.†Â
In related research, a review using California Department of Pesticide Regulation fruit and vegetable test data conducted by the Environmental Working Group (EWG), PFAS pesticides were found in peaches, strawberries, and other popular fruits. According to the report, “Out of 930 samples of 78 types of non-organic, California-grown fruits and vegetables tested, 348 samples, or 37%, had traces of PFAS pesticides, based on state testing data EWG reviewed.â€
EPA Continues to Register PFAS Pesticides, with Declaration of an “Emergency
Policy and toxicology are slated to collide as EPA considers allowing the use of the PFAS pesticide, tetflupyrolimet, by invoking an emergency waiver process in federal pesticide law. If authorized, EPA’s decision will permit the use of an unregistered pesticide under an emergency waiver provision—in this case, an emergency caused by weed resistance to weed killers (herbicides) on the market. EPA is accepting public comments until March 16, 11:59 pm EDT. Beyond Pesticides is urging the public to object to EPA approval by writing to EPA and Congress stating that herbicide resistance is not an emergency and PFAS chemicals must not be broadcast in the environment.Â
Meanwhile, EPA continues to register PFAS pesticides through its normal registration review process. (See Daily News At Odds with Intl Regulatory Bodies, EPA Defines Away PFAS Problem, Allows Widespread Contamination.) The latest pesticide proposed for EPA registration, epyrifenacil (agricultural weed killer), joins cyclobutrifluram (soil fungicide/nematicide), isocycloseram (household and agricultural insecticide), diflufenican (lawn and agricultural weed killer), and trifludimoxazin (agricultural weed killer), making a total of five PFAS pesticide proposals in 2025 that have been associated with national and worldwide contamination of food, land, and water. Two of these, cyclobutrifluram and isocycloseram, have been approved as of last fall.
The Organic Solution
As PEER points out in their press release: “‘Land managers have safer, proven alternatives to spraying Rejuvra,’ said David Jenkins, former Senior Executive at BLM. ‘Mechanical removal, restoration with native plants, and improved grazing management can reduce invasive grasses without introducing new toxic risks.’â€
With EPA’s failure to perform its statutory duty to adequately protect the health of the environment and all organisms within it, as extensively covered by Beyond Pesticides, the call to truly safeguard ecosystems and public health with the elimination of pesticides, including all herbicides like indaziflam and all PFAS, takes on a greater urgency. Instead of creating a complicated workaround that will not address the urgent health, biodiversity, and climate crises, EPA must cancel registrations of pesticides that harm health and the environment and facilitate a widescale conversion to organic practices.
The holistic, systems-based organic solution for land management and agriculture offers numerous health and environmental benefits. Learn more about how to take action and have your voice heard on governmental efforts that are harmful to the environment and public and worker health, increase overall pesticide use, and undermine the advancement of organic, sustainable, and regenerative practices and policies here.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source:
Rosenthal, C. and Jenkins, D. (2026) New Testing Detects Toxic PFAS in Herbicide Applied Across Public Lands, Public Employees for Environmental Responsibility (PEER). Available at: https://peer.org/new-testing-detects-toxic-pfas-in-herbicide-applied-across-public-lands/.
