Material selection in the chemistry value chain involves consideration of many objectives, including cost, performance, health risk, and environmental impact. Alternatives assessment is an emerging tool for guiding complex decisions with respect to these goals. As a relatively new method, the process is not yet well developed, especially with respect to how trade-offs among objectives can be assessed accurately and inexpensively. Using paint strippers alternatives assessment as an illustrative example, we show how an established decision-analytic method, known as comparative screening, allows for a multistep process with gradually increasing information needs. Compared with existing methodological approaches, comparative screening instills flexible and consistent treatment of trade-offs. This is important because it maximizes the potential for a robust assessment while minimizing arduous data collection. Further, its use in the alternatives assessment process can support the selection of more sustainable materials.

Emissions of plastic waste to the environment and the subsequent degradation into microplastic particles that have the potential to interact with biological organisms represent a concern for global society. Current understanding of the potential impacts on aquatic and terrestrial population stability and ecosystem structure and function associated with emissions of microplastic particles is limited and insufficient to fully assess environmental risks. Multistakeholder discussions can provide an important element in helping to identify and prioritize key knowledge gaps in assessing potential risks. In the present review, we summarize multistakeholder discussions from a 1-d International Council of Chemical Associations-sponsored symposium, which involved 39 scientists from 8 countries with representatives from academia, industry, and government. Participants were asked to consider the following: discuss the scientific merits and limitations of applying a proposed conceptual environmental risk assessment (ERA) framework for microplastic particles and identify and prioritize major research needs in applying ERA tools for microplastic particles. Multistakeholder consensus was obtained with respect to the interpretation of the current state of the science related to effects and exposure to microplastic particles, which implies that it is unlikely that the presence of microplastic in the environment currently represents a risk. However, the quality and quantity of existing data require substantial improvement before conclusions regarding the potential risks and impacts of microplastic particles can be fully assessed. Research that directly addresses the development and application of methods that strengthen the quality of data should thus be given the highest priority. Activities aimed at supporting the development of and access to standardized reference material were identified as a key research need. Environ Toxicol Chem 2019;38:2087-2100. (c) 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.

Emissions of plastic waste to the environment and the subsequent degradation into microplastic particles that have the potential to interact with biological organisms represent a concern for global society. Current understanding of the potential impacts on aquatic and terrestrial population stability and ecosystem structure and function associated with emissions of microplastic particles is limited and insufficient to fully assess environmental risks. Multistakeholder discussions can provide an important element in helping to identify and prioritize key knowledge gaps in assessing potential risks. In the present review, we summarize multistakeholder discussions from a 1‐d International Council of Chemical Associations– sponsored symposium, which involved 39 scientists from 8 countries with representatives from academia, industry, and government. Participants were asked to consider the following: discuss the scientific merits and limitations of applying a proposed conceptual environmental risk assessment (ERA) framework for microplastic particles and identify and prioritize major research needs in applying ERA tools for microplastic particles. Multistakeholder consensus was obtained with respect to the interpretation of the current state of the science related to effects and exposure to microplastic particles, which implies that it is unlikely that the presence of microplastic in the environment currently represents a risk. However, the quality and quantity of existing data require substantial improvement before conclusions regarding the potential risks and impacts of microplastic particles can be fully assessed. Research that directly addresses the development and application of methods that strengthen the quality of data should thus be given the highest priority. Activities aimed at supporting the development of and access to standardized reference material were identified as a key research need. Environ Toxicol Chem 2019;38:2087–2100. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on

To assess human health risks associated with chemicals, risk assessors often utilize models that evaluate the health effects of a chemical constituent based on inherent characteristics and the potential for human exposure to the chemical. The complexity of these models, however, makes them difficult to adopt. A simplified, screening-level assessment is needed. Although several approaches exist for screening chemical ingredient hazards in consumer and commercial products, few exist that allow users to combine this hazard information with exposure potential to screen ingredients or products based on risk. In this paper, we propose a tiered approach to effectively screen product ingredients using readily accessible public information. This approach evaluates hazard using the Globally Harmonized System for Classification and Labeling along with environmental persistence and bioaccumulation data. Based on the hazard results, one can then assess product ingredients for exposures that may lead to negative health effects. Ingredients that present low hazard, or have minimal exposure levels, are considered low priority. For ingredients that do not pass an initial hazard and exposure screen, more sophisticated approaches may be used to further evaluate the likelihood and extent of potential exposures. Each evaluation tier is designed to be conservative to provide an approach that helps to achieve safe use of the product.

BACKGROUND:The Life Cycle Initiative, hosted at the United Nations Environment Programme, selected human toxicity impacts from exposure to chemical substances as an impact category that requires global guidance to overcome current assessment challenges. The initiative leadership established the Human Toxicity Task Force to develop guidance on assessing human exposure and toxicity impacts. Based on input gathered at three workshops addressing the main current scientific challenges and questions, the task force built a roadmap for advancing human toxicity characterization, primarily for use in life cycle impact assessment (LCIA). OBJECTIVES:The present paper aims at reporting on the outcomes of the task force workshops along with interpretation of how these outcomes will impact the practice and reliability of toxicity characterization. The task force thereby focuses on two major issues that emerged from the workshops, namely considering near-field exposures and improving dose–response modeling. DISCUSSION:The task force recommended approaches to improve the assessment of human exposure, including capturing missing exposure settings and human receptor pathways by coupling additional fate and exposure processes in consumer and occupational environments (near field) with existing processes in outdoor environments (far field). To quantify overall aggregate exposure, the task force suggested that environments be coupled using a consistent set of quantified chemical mass fractions transferred among environmental compartments. With respect to dose–response, the task force was concerned about the way LCIA currently characterizes human toxicity effects, and discussed several potential solutions. A specific concern is the use of a (linear) dose–response extrapolation to zero. Another concern addresses the challenge of identifying a metric for human toxicity impacts that is aligned with the spatiotemporal resolution of present LCIA methodology, yet is adequate to indicate health impact potential. CONCLUSIONS:Further research efforts are required based on our proposed set of recommendations for improving the characterization of human exposure and toxicity impacts in LCIA and other comparative assessment frameworks. https://doi.org/10.1289/EHP3871.

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).

Scott M. Arnold, Bill Greggs, Katy O. Goyak, Bryce D. Landenberger , Ann M. Mason, Brett Howard, Rosemary Zaleski, Brett Howard, J.D., Ph.D., Rosemary T. Zaleski, PhD Product Sustainability Consulting Leader, Toxicology and Environmental Research & Consulting, The Dow Chemical Company, 1803 Building, Midland, MI 48674 USA, Phone: 989.636.4843, Fax: 989.636.1875, smarnold@dow.com President, Soleil Consulting, LLC, 4195 Dingman Dr, Sanibel, FL 33957-5107, (239) 472-6060, bgreggs@gmail.com Senior Toxicologist, ExxonMobil Biomedical Sciences, Inc., 1545 US Highway 22 East, Annandale, NJ 08801-3059, 908 335 1017 Tel, 908 73

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Disubstituted alpha-hydroxy acids have been synthesized by metal-catalyzed silylene transfer to alpha-keto esters. A range of substituents are tolerated in the transformation with the exception of branched groups at the vinylic position. The alpha-hydroxy acid products can be converted into gamma-lactones using a variety of lactonization conditions.

Disubstituted alpha-hydroxy acids have been synthesized by metal-catalyzed silylene transfer to alpha-keto esters. A range of substituents are tolerated in the transformation with the exception of branched groups at the vinylic position. The alpha-hydroxy acid products can be converted into gamma-lactones using a variety of lactonization conditions. (C) 2009 Elsevier Ltd. All rights reserved.

This communication demonstrates the generality of the silylene transfer/sigmatropic rearrangement strategy to create highly functionalized small molecules with good stereocontrol. The original report by the same group focused on α,β-unsaturated esters (Org. Lett. 2007, 9, 1037; see also Synfacts 2007, 519). The isobutene precursor 2 gave 3 in higher yields with α-keto esters 1 than the cyclohexene silylene used previously. Retention of stereochemical information was confirmed, and even a remote stereocenter in 8 imparted acceptable levels of diastereoselectivity (dr = 9:1).

Alpha-keto esters can be converted into alpha-hydroxy acids in a single flask involving metal-catalyzed silylene transfer, 6pi-electrocyclization, Ireland-Claisen rearrangement, and hydrolysis. This reaction sequence is stereoselective and tolerates alkyl- and aryl-substituted alpha-keto ester substrates as well as an alpha-imino ester.

Polypeptide libraries cast a broad net for defining enzyme and binding protein specificities. In addition to uncovering rules for molecular recognition, the binding preferences and functional group tolerances from such libraries can reveal mechanisms underlying biochemical and cellular processes. Ligands obtained from protein libraries can also provide pharmaceutical lead compounds and even reagents to further explore cell biology. Here, we review selected recent examples of protein libraries demonstrating these principles. In particular, we focus on combinatorial libraries composed of randomized peptides or variations of a single protein. The characteristics of various techniques for library constructions and screening are also briefly surveyed.

This manuscript describes the synthesis of fused polycyclic ethers from the coupling of C-glycoside forming reactions with ring closing metathesis and acid mediated annulation reactions.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.