Advancing EPA’s Understanding of the Next Generation of Pesticides

Published May 9, 2022

Some pests, like rodents, insects, and fungi, can pose a variety of problems for humans, including carrying disease and threatening agricultural food supplies. Pesticides – that is, any product used to prevent, repel, or destroy such pests – provide a tool to fight back against these problems. But pesticides can create even bigger problems if they pose a risk of concern to people, non-target species, or the ecosystem. EPA’s mission to protect human health and the environment includes regulating and overseeing the pesticides entering the consumer market and our environment. 

Before a manufacturer can sell a pesticide in the United States, EPA must evaluate it thoroughly to ensure it meets safety standards to protect human health and the environment. EPA grants a "registration" or license that permits a pesticide's distribution and use only after the company meets the scientific requirements. Providing scientific data on the composition, potential adverse effects, and environmental fate of each pesticide allows EPA to evaluate whether a pesticide could harm certain nontarget organisms and endangered species.

Over the past decade, EPA has received an increasing number of pesticide product applications that potentially contain nanomaterials. Nanomaterials are tiny substances with particle sizes generally less than 100 nanometers (nm) in size – for scale, a typical germ or microbe is about 1000 nm. Nanotechnology lets scientists tailor the structures of materials at extremely small scales to achieve certain properties. 

“Nanopesticides do show remarkable advantages over conventional pesticides,” says EPA scientist Dr. Chunming Su, who has been researching nanomaterials for over a decade. “The smaller particles of the active ingredient in a nanopesticide mean you don’t have to use as much pesticide. Nanotechnology can also be used to encapsulate the active ingredient to make it responsive to the environment, only releasing it under certain moisture or pH conditions.”

But EPA’s current pesticide review method wasn’t designed for nanomaterials, so each product is reviewed on a case-by-case basis. The Agency needed a way to standardize their process for determining whether a pesticide product contains nanomaterials. 

“As the technology behind pesticides advances, some registrants are turning to nanomaterials to meet their needs, and EPA must evaluate these new materials using the best available science,” says Dr. Andrew Byro of EPA’s Office of Pesticide Programs, the office that oversees the pesticide registration process.

To meet this need, an EPA research team led by Dr. Su conducted an exhaustive search for patents and published literature related to nanopesticides to understand the state-of-the-science. The team found and analyzed over 36,000 patents and 500 peer-reviewed journal articles. From their research findings, the team established two general categories of nanopesticides to help inform EPA’s regulatory reviews: 1) products with mostly metal-based nanomaterials as the active ingredient, like nanosilver and nanocopper oxide/hydroxide, and 2) products that encapsulate and carry the active ingredient using nanomaterials (mostly carbon based) like graphene and carbon nanotubes. 

The research team also developed a review framework that includes a simple decision tree to determine what products should be classified and evaluated as a nanopesticide. If a product is determined to contain a nanomaterial, then it will be subject to additional assessment or data needs from the manufacturer. 

“This framework represents a major steppingstone in the development of a method for identification of nanomaterials. This framework will be used as a platform to help inform EPA’s data needs and future determinations regarding the evaluation of nanomaterials in antimicrobial pesticides,” says Dr. Byro.

The research team collected their findings related to the physical and chemical properties and efficacy of nanopesticides in a peer-reviewed journal article in Nature Nanotechnology. The team found that nano-enabled pesticides adhere better to plant surfaces and have a reduced impact on non-target organisms. Nanopesticides may also enhance plant resilience against stressors from heat or drought. These benefits could lead to higher crop yield and provide more agricultural resilience to address climate change and weather extremes. The team’s findings also highlight the data gaps and the need for additional research on potential adverse impacts of nanopesticides.

Nanopesticides show great promise for effective pest management, sustainable agriculture, and global food security, but only if we harness their benefits appropriately and safely. The findings of this work will help guide future research to maximize the benefits of nanopesticides while minimizing the potential adverse impacts. This foundational work furthers EPA’s understanding of this next-generation technology, enabling the Agency to better respond to changing landscape of the pesticide market and better protect human health and the environment. 

Learn More:

Nano-enabled pesticides for sustainable agriculture and global food security, published in the journal Nature Nanotechnology.