Transforming the evaluation of agrochemicals

Abstract

The present agrochemical safety evaluation paradigm is long-standing and anchored in well-established testing and evaluation procedures. However, it does not meet the present-day challenges of rapidly growing populations, food insecurity, and pressures from climate change. To transform the current framework and apply modern evaluation strategies that better support sustainable agriculture, the Health and Environmental Sciences Institute (HESI) assembled a technical committee to reframe the safety evaluation of crop-protection products. The committee is composed of international experts from regulatory agencies, academia, industry and nongovernmental organizations. Their mission is to establish a framework that supports the development of fit-for-purpose agrochemical safety evaluation that is applicable to changing global, as well as local needs and regulatory decisions, and incorporates relevant evolving science. This will be accomplished through the integration of state-of-the-art scientific methods, technologies and data sources, to inform safety and risk decisions, and adapt them to evolving local and global needs. The project team will use a systems-thinking approach to develop the tools that will implement a problem formulation and exposure driven approach to create sustainable, safe and effective crop protection products, and reduce, replace and refine animal studies with fit-for-purpose assays. A new approach necessarily will integrate the most modern tools and latest advances in chemical testing methods to guarantee the robust human and environmental safety and risk assessment of agrochemicals. This article summarizes the challenges associated with the modernization of agrochemical safety evaluation, proposes a potential roadmap, and seeks input and engagement from the broader community to advance this effort. © 2022 Health and Environmental Sciences Institute (HESI). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Keywords: crop protection; pesticide; risk assessment; safety assessment; testing.

Figure 1

Techno‐regulatory conceptual landscape map illustrating the various parts that need to be considered in a conceptual model. A clear common goal is to create an agricultural system that provides a just, sustainable and healthy environment. Over time, continuous investment has resulted in scientific developments through the 20th and 21st centuries (the ‘river of science’) that has produced and will continue to produce substantial scientific progress in the development of NAMs. Although existing tools have generated useful information, often the associated data are hidden in inaccessible documents in repositories that prevent their effective use. Additionally, many of these old tools increasingly are seen as unethical, unfit or impractical for use in contemporary safety evaluation. To date, apart from a few notable exceptions, most of the NAM advances remain unused in regulatory application. This pool of currently unused ideas and the currently inaccessible historic toxicology data can become the new toolkit that will significantly modernize agrochemical safety assessments – but only if we can overcome the many various technical and conceptual barriers to their application. We also must acknowledge that there are philosophical differences between countries in terms of their use of solely science‐based risk assessments (‘safety land’) and those regions that also have additional emphasis on hazard‐based precautionary criteria in addition to their safety assessments (‘precaution land’). This philosophical difference naturally means that there is not one approach but an acknowledgement that different routes from these different starting points in our techno‐regulatory landscape will have to be developed, so that progress towards a common goal – albeit at different speeds and by different routes – will traverse the existing barriers. Therefore, the TEA project aims to map this current landscape in detail to inform building the roadmaps through the existing and anticipated future scientific, technical, regulatory, policy and legal landscapes that will enable a transformation of the evaluation of crop protection methods, and better reflect current and emerging evidence‐based requirements for agrochemicals.

Figure 2

Project structure to address each problem statement. As this is a global activity, separate region‐specific subgroups within each subcommittee were established to maximize input and fully address each problem. The numbering represents the order in which these problem statements will be addressed as they build on each other, for example 1a and 1b are being addressed simultaneously with separate groups of subject matter experts.

Figure 3

The TEA project will aim to identify what current tools and what additional tool development will be necessary to change the agrochemical testing paradigm quickly and efficiently. The toolkit can be considered as ranging from the current guideline studies in model species where we observe toxicity, to a future state where we have a suite of sufficiently descriptive mechanistic quantitative multiscale models that comprehensively covers the entirety of regulatory endpoints of concern and is rapidly informed by chemical specific data. It is anticipated that mechanistic model‐based approaches will permit more rapid and sustained high quality decision making. However, the current state of the science does not provide similar levels of technological readiness across this full spectrum of tools. Nevertheless, the goal is to make practical improvements to safety assessment and not delay until we create a theoretically perfect system. Therefore, the identification of existing NAMs that both accelerate the speed to decisions, and maintain or improve on the current quality of those decisions, is an important early goal of the project. This output represents the ‘good enough toolkit’, where we can efficiently and confidently implement a sufficiently rapid decision‐making process.

Figure 4

Technical innovations and changes in thinking necessary to transform paradigms. The TEA project will aim to explore routes to implementation of NAMs and whether their continuous improvement and incremental innovation of the existing tools will be sufficient (i). If new technologies can be effectively incorporated into the mindset prevalent in people using the existing paradigm (ii) this will create some burden for acceptance and (re)training. More challenging, but perhaps with the greatest potential for rapid uptake, it may be possible to use existing tools to support safety assessment after a mindset transformation to a new paradigm using already trusted tools (iii). Finally, if new technological tools must be integrated, it will take a mindset change in people who will use the new paradigm built on scientific innovation (Fig. 4, vertical dimension).