Risk assessment in the 21st century: Roadmap and matrix

Abstract

The RISK21 integrated evaluation strategy is a problem formulation-based exposure-driven risk assessment roadmap that takes advantage of existing information to graphically represent the intersection of exposure and toxicity data on a highly visual matrix. This paper describes in detail the process for using the roadmap and matrix. The purpose of this methodology is to optimize the use of prior information and testing resources (animals, time, facilities, and personnel) to efficiently and transparently reach a risk and/or safety determination. Based on the particular problem, exposure and toxicity data should have sufficient precision to make such a decision. Estimates of exposure and toxicity, bounded by variability and/or uncertainty, are plotted on the X-and Y-axes of the RISK21 matrix, respectively. The resulting intersection is a highly visual representation of estimated risk. Decisions can then be made to increase precision in the exposure or toxicity estimates or declare that the available information is sufficient. RISK21 represents a step forward in the goal to introduce new methodologies into 21st century risk assessment. Indeed, because of its transparent and visual process, RISK21 has the potential to widen the scope of risk communication beyond those with technical expertise.

The need for strategic development of safety sciences

“…This process was created to address a needed transition in toxicology, exposure, and risk assessment methodology and communication to develop a cohesive framework that is practicable for risk assessment. A number of papers (Embry et al, 2014;Pastoor et al, 2014;Simon et al, 2014;Moretto et al, 2016;Solomon et al, 2016) and a web-based tool 19 have been published. The most distinctive aspect of RISK21 is that exposure drives the data acquisition.…”

Problem formulation for risk assessment of combined exposures to chemicals and other stressors in humans

“…As discussed in Embry et al (2014), different amounts of data will be required for different tiers. Lower tiers based on deterministic hazard quotients require few data but are usually very conservative.…”

“…RISK21 has developed a conceptual framework that is a PF-based, exposure-driven paradigm that takes maximum advantage of existing information and aids in identifying when additional data are needed to make a decision. The overarching principles of the RISK21 approach are introduced by Pastoor et al (2014) and explained in detail in Embry et al (2014).…”

International regulatory needs for development ofan IATA for non-genotoxic carcinogenic chemical substances

“…Inflammation is a major early stage, since these are outside the scope of the intrinsic hazard profile. The reader is referred to more authoritative sources for the conduct of an exposure assessment, e.g., Embry et al (2014). The governance of IATA activities is in development under the auspices of the OECD.…”