A quantitative screening-level approach to incorporate chemical exposure and risk into alternative assessment evaluations
Authors: Arnold Scott M , Greggs Bill , Goyak Katy O , Landenberger Bryce D , Mason Ann M , Howard Brett , Zaleski Rosemary T 
Published: March 2017

Abstract

As the general public and retailers ask for disclosure of chemical ingredients in the marketplace, a number of hazard screening tools were developed to evaluate the so-called “greenness” of individual chemical ingredients and/or formulations. The majority of these tools focus only on hazard, often using chemical lists, ignoring the other part of the risk equation: exposure. Using a hazard-only focus can result in regrettable substitutions, changing 1 chemical ingredient for another that turns out to be more hazardous or shifts the toxicity burden to others. To minimize the incidents of regrettable substitutions, BizNGO describes “Common Principles” to frame a process for informed substitution. Two of these 6 principles are: “reduce hazard” and “minimize exposure.” A number of frameworks have emerged to evaluate and assess alternatives. One framework developed by leading experts under the auspices of the US National Academy of Sciences recommended that hazard and exposure be specifically addressed in the same step when assessing candidate alternatives. For the alternative assessment community, this article serves as an informational resource for considering exposure in an alternatives assessment using elements of problem formulation; product identity, use, and composition; hazard analysis; exposure analysis; and risk characterization. These conceptual elements build on practices from government, academia, and industry and are exemplified through 2 hypothetical case studies demonstrating the questions asked and decisions faced in new product development. These 2 case studies—inhalation exposure to a generic paint product and environmental exposure to a shampoo rinsed down the drain—demonstrate the criteria, considerations, and methods required to combine exposure models addressing human health and environmental impacts to provide a screening level hazard and exposure (risk) analysis. This article informs practices for these elements within a comparative risk context to improve alternatives assessment evaluation and decision making. Integr Environ Assess Manag 2017;13:1007–1022. © 2017 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC)

Key Points
This article presents 2 generic case studies to demonstrate how both the hazard and exposure can be added into as a single step into an AA evaluation. In practice, drop-in ingredient substitution of 1 chemical ingredient performing a functional role for another is atypical because changing a substance often requires a critical evaluation of the entire formulation to ensure the redesigned product meets performance and other attributes. The results from these 2 case studies indicate that both human and environmental exposure information influence the alternative selection process, and an evaluation of both are needed to identify the most appropriate candidate alternatives for product development. Consumers in the market place are searching for products that they believe to contain “safer” chemicals and the practice of considering both hazard, and exposure in an alternative assessment can inform the selection of candidate chemicals.