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Committee on the Design and Evaluation of Safer Chemical Substitutions: A Framework to Inform Government and Industry Decision; Board on Chemical Sciences and Technology; Board on Environmental Studies and Toxicology; Division on Earth and Life Studies; National Research Council. A Framework to Guide Selection of Chemical Alternatives. Washington (DC): National Academies Press (US); 2014 Oct 29.

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A Framework to Guide Selection of Chemical Alternatives.

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2Existing Frameworks and Approaches

The literature base for alternatives assessment and chemical substitution describes how methods, substitution guidance, and case studies have developed, leading to the availability of different approaches. These approaches tend to have varying sets of criteria with different weighting systems for evaluating current chemicals and possible substitutes. For example, some manufacturers may seek substitutes for priority or controversial chemicals and precursor materials that appear on a list developed by one or more regulatory agencies (“list-based” alternatives assessment). Other manufacturers report that they go beyond regulatory restrictions in selecting the chemicals they will use (Lavoie et al. 2010) as part of their sustainability programs. Retailers may seek to certify that the products they sell exhibit superior environmental performance. Different assessment frameworks can yield different results depending on the focus of the framework.


As discussed in Chapter 1, for a more detailed consideration, the committee identified a subset of publicly available frameworks and approaches used to conduct alternatives assessments. Several frameworks were identified in the Organisation for Economic Development (OECD) report, Current Landscape of Alternatives Assessment Practice: A Meta-Review (OECD 2013a). In this report, the OECD's Ad Hoc Group on Substitution of Harmful Chemicals compiled extensive information on frameworks, methods, and tools that can be used for assessing alternatives to chemicals of concern. The primary attributes of these frameworks and approaches are presented in Table 2-1 and described here.

TABLE 2-1. Comparison of Selected Attributes Found in Selected Frameworks .


Comparison of Selected Attributes Found in Selected Frameworks .

BizNGO Alternatives Assessment Protocol: The Business-Nongovernmental Organization Working Group's BizNGO Chemical Alternatives Assessment Protocol (BizNGO CAAP7) became publicly available in 2011. The Business-NGO Working Group, a project of the non-profit Clean Production Action organization, designed the protocol to codify practices that have been shown to work well for businesses that are “downstream users” of chemicals. According to the Business-NGO Working Group, such businesses are not invested in the use of any particular chemical but rather tend to focus on the function the chemicals provide to achieve product performance (Rossi et al. 2012).

The BizNGO CAA protocol (Rossi et al. 2012) is based around a 7-step decision tree. The BizNGO CAA protocol recommends ordered steps for carrying out an alternatives assessment without prescribing how to carry out each step (OECD 2013a). For example, the protocol includes life cycle assessment and risk assessment as two separate steps, noting that they are not always necessary or appropriate for selecting an alternative (OECD 2013a). The protocol calls for applying Life Cycle Thinking to identify concerns related to potential substitutes' life cycle and exposure.

California's Alternatives Analysis program joins alternatives assessment to a decision process for selecting a course of action intended to decrease toxic threats (Kuczenski et al. 2010). California's 2008 Safer Consumer Product laws8 require manufacturers or other responsible entities to seek safer alternatives to harmful chemical ingredients in widely used products (CADTSC 2013a). The overarching goal of the regulations is to create a predictable and systematic process for reducing toxic ingredients in consumer products (Kuczenski et al. 2010). The law prescribes which elements need to be included in identifying and evaluating safer chemical substitutions and engineering design alternatives, including analyses of use-based exposure and risk, cost and availability, life cycle impacts, and social impacts. California's Alternatives Analyses includes two required phases. The first phase is a screening process focusing on identifying what alternatives will be considered and asking whether the chemical itself or a replacement chemical or design is necessary to achieve the function of the chemical of concern.

The second phase takes a much more in-depth look at the alternatives. Several evaluation modules with methods for examining exposure pathways and life cycle phases are included in this second step. The state mandates that a large number of different criteria be evaluated in its chemical alternatives analyses, using methods that are transparent and well documented. To support implementation of the process, the state is producing guidance for alternatives analysis.

Design for the Environment Chemical Alternatives Assessments: The U.S. Environmental Protection Agency (EPA) Office of Chemical Safety and Pollution Prevention (OCSPP) created a Design for the Environment (DfE) Program Alternatives Assessment framework in 2011 (EPA 2014). This 7-step framework was developed with input from the agency's Toxic Substances Control Act (TSCA) New Chemicals Program and DfE's Cleaner Technology Substitutes Assessments.

EPA's DfE's alternatives assessment process includes specific guidelines for evaluating chemicals for carcinogenicity, mutagenicity, reproductive and developmental toxicity, acute and repeat dose toxicity, toxicity to aquatic organisms, and environmental fate (Whittaker and Heine 2013). DfE has also developed specific Criteria for Hazard Evaluation (EPA 2011a), which define low, moderate, and high hazard designations for alternatives assessments. Both experimental and modeled data can be used in assigning these hazard designations. In the absence of experimental data, measured data from a suitable analog are preferred over estimated data (Whittaker and Heine 2013).

EPA has applied its DfE alternatives assessment methodology to nonylphenol ethoxylates (NPEs), surfactants, flame retardants in furniture and printed circuit boards, and decabromodiphenyl ether (decaBDE) in building materials, textiles, wiring insulation, and plastics. The agency is currently assessing alternative chemicals that can be used in place of certain phthalates, BPA in thermal paper, and hexabromocyclododecane in expandable foam for insulation.

German Guide on Sustainable Chemicals: The German Federal Environmental Agency's Guide on Sustainable Chemicals (German Guide) (Reihlen et al. 2011) is intended to help business enterprises systematically implement sustainable chemistry in their daily practice. Published in 2011, it includes specific guidelines for evaluating intrinsic chemical hazards and analyzing social and life cycle impacts (OECD 2013a).

Interstate Chemicals Clearinghouse (IC2) Alternatives Assessment Guide: The Interstate Chemicals Clearinghouse's (IC2) developed the Alternatives Assessment Guide (IC2 2013) based on input from experts from California, Connecticut, Michigan, Minnesota, New York, and Oregon and is funded by a grant from the EPA to Washington State.

The IC2 Alternatives Assessment Guide focuses on “reducing risk by reducing hazard” (OECD 2013a). The guidance includes a set of principles for alternatives assessments (OECD 2013a), and three decision-making framework options: sequential, simultaneous, and hybrid (IC2 2013). IC2's frameworks stand out for including flexibility as a principle and mentioning the role of green chemistry as an approach for designing safer chemicals (OECD 2013a). The IC2 framework includes seven modules, each evaluating a different consideration for assessing potential alternatives, which users can choose among to conduct an assessment. It also outlines the minimum set of modules that are recommended for a good alternatives assessment. IC2 has also created a Safer Alternatives Assessment Wiki (IC2 2014) to share resources and approaches.

Lowell Center Alternatives Assessment Framework: The University of Massachusetts at Lowell's Center for Sustainable Production's Alternatives Assessment Framework (Lowell AAF) (Rossi et al. 2006) grew out of a 2004 workshop (Lowell 2005) and builds on a methodology developed at the Center's sister organization, the University of Massachusetts at Lowell's Toxics Use Reduction Institute (TURI) (Rossi et al. 2006).

Like the Biz-NGO framework, the Lowell AAF lays out a series of steps and modules to evaluate alternatives, but does not specify methods or tools for completing analyses. The framework is intended to facilitate the relatively quick assessment of “safer and more socially just alternatives to chemicals, materials, and products of concern” (Rossi et al. 2006). It was created to be an open-source approach to foster collaborative development, sharing, and growth of methods, tools, and databases that facilitate decision-making.

REACH Guidance on the Preparation of an Application for Authorisation: The European Chemicals Agency's Chemical Safety Assessment protocol's Guidance on the Preparation of an Application for Authorisation (ECHA 2011) is intended to support the implementation of European Union (EU) Registration, Evaluation, Authorisation, and Restriction of Chemicals (REACH) regulations (ECHA 2014b). REACH has been a major governmental driver for chemical substitution (Tickner et al. 2013). It requires that manufacturers, importers, and downstream users seeking authorization to use identified “chemicals of concern” conduct an assessment of the chemical alternatives. Where the analysis demonstrates that suitable substitutes exist, the applicant must develop a timetable for proposed actions. Based on the suitability of the alternatives, EU government authorities determine whether or not they will continue to authorize applicants to use the substance(s) of concern.

The guidance details how to prepare chemical safety authorization applications, including alternatives assessments. Once possible alternatives have been identified, it specifies that the analysis should involve assessing the alternatives for: technical feasibility; potential risks to the environment and human health; economic feasibility; suitability and availability; as well as identifying relevant research and development. The recommendations for how to assess alternative chemicals' costs, performance, and socioeconomic impact are particularly detailed (OECD 2013a).

TURI Alternatives Assessment Process Guidance: The University of Massachusetts at Lowell's TURI was established as part of a 1989 Massachusetts law requiring manufacturing firms to undertake toxics use reduction planning. In 2005, the Massachusetts state legislature requested that TURI evaluate alternatives to five chemicals of concern. TURI's Alternatives Assessment Process Guidance (TURI 2006a) is an outgrowth of the resulting Five Chemicals Alternatives Assessment Study (TURI 2006b). The objective of the guidance document was to define a consistent process for setting priorities, studying and evaluating the alternatives for the five chemicals (lead, formaldehyde, perchloroethylene, hexavalent chromium, and di (2-ethylhexyl) phthalate [DEHP]) (TURI 2006a). The document recommends steps for carrying out an alternatives assessment without prescribing how to carry out each step (OECD 2013a).

UNEP Persistent Organic Pollutants Review Committee General Guidance on Alternatives: The United Nations Environment Programs (UNEP) Persistent Organic Pollutants Review Committee's “General guidance on considerations related to alternatives and substitutes for listed persistent organic pollutants and candidate chemicals” (UNEP General Guidance on Alternatives) (UNEP 2009) was adopted in 2009. Similar to BizNGO and Lowell, the UNEP guidance suggests a series of steps that can be used to assess potential alternatives to persistent organic pollutants (POPs), and provides narrative guidance on how each step might be executed. It also provides examples of ways to present results from the assessment, but does not give guidance on weighting of factors or resolving trade-offs between different domains, except to require the screening out of other POPs.


GreenScreen® for Safer Chemicals: In addition to the frameworks above, the committee considered the GreenScreen® for Safer Chemicals tool because it is integral or related to several of the frameworks and is specifically intended for comparative chemical hazard assessment (Clean Production Action 2014; GreenScreen® hazard assessment tool; Heine and Franjevic 2013). GreenScreen® was developed by Clean Production Action, an organization developing tools and strategies in the green chemical space. GreenScreen® is a tool for “benchmarking9” the data on chemicals' ecotoxicity and human health hazard data. Benchmark 1 is “Avoid chemicals of high concern.” Benchmark 2 is “Use but search for safer substitutes.” Benchmark 3 is “Use but still opportunity for improvement.” Finally, Benchmark 4 is “Safe chemical.” Specific hazard and assessment criteria are defined for each of these benchmarks, as described in Chapter 8.

UCLA Multi-Criteria Decision Analysis: MCDA methods are a decision analytic tool designed to provide a clear, formal approach to allow decision-makers to evaluate alternatives (Malloy et al. 2011). They present a comparative evaluation of the alternatives based upon provided criteria, taking into account the relative importance of those criteria (Kuczenski et al. 2010). More specifically, the application of Multi-Criteria Decision Analysis tools to alternatives assessment has been most notably explored by The University of California at Los Angeles (UCLA) Sustainable Technology and Policy Programand is sometimes referred to as the UCLA MCDA framework, as listed in Table 2-1. This framework or application of MCDA tools is the outgrowth of a pilot project to develop and evaluate an alternatives analysis methodology that is consistent with California's Safer Consumer Product Regulations (Kuczenski et al. 2010). The project involved using two different MCDA approaches and supporting decision-analysis software. According to Malloy (Malloy et al. 2011), the results demonstrate that the models can produce a transparent evaluation that ranks alternatives and explains how the alternatives' performance on various criteria affected their ordering. The models also allow the methods' assumptions to be adjusted (Malloy et al. 2011).


Most of the Chemical Alternatives Assessment frameworks evaluated by the committee characterize hazard, environmental fate, ecotoxicity, human health, and physicochemical properties, although each framework varies in how those attributes are assessed (OECD 2013a). A comparison of several attributes that vary amongst the alternatives assessment frameworks is presented in Table 2-1.

Hazard, human health and physicochemical properties are each assessed by all of the frameworks evaluated by the committee: BizNGO, CA SCP, EPA DfE, German Guide, IC2, Lowell, REACH, TURI, UCLA MCDA, and UNEP. Eight of the ten frameworks examined include environmental fate (BizNGO, EPA DfE, German Guide, IC2, REACH, TURI, UCLA MCDA, UNEP) and ecotoxicity (BizNGO, CA SCP, EPA DfE, IC2, REACH, TURI, UCLA MCDA, UNEP) in their analyses. Some, but not all, frameworks consider life cycle analysis (or Life Cycle Thinking depending upon the framework; see Chapter 10 for a description of Life Cycle Thinking) and the chemical's functional use or application. Life Cycle Thinking identifies hazards from chemical manufacture through product manufacture, use, and disposal and can also help identify important consumer, worker, and environmental exposure pathways. This can be especially important for consumer products. The types of end points (e.g., mammalian toxicity, ecotoxicity), range of outcomes (e.g., toxicological thresholds), and categories used to categorize hazards within a framework can vary somewhat between alternatives assessment frameworks and are considered in greater detail in subsequent chapters of this report.

Many groups have developed more specific “principles” to inform the assessment process. For example, the OECD report identified several sets of principles that are intended to guide the evaluation of safer chemical substitutes, including principles from the Interstate Chemicals Clearinghouse (IC2), the Commons Principles For Alternatives Assessment (BizNGO 2013) and the EPA's Design for Environment Program (OECD 2013a). These “principles” have a number of commonalities, and while some are not necessarily scientific principles, they are meant to guide an informed and thoughtful scientific review process for evaluating alternatives to chemicals of concern. These commonalities among the reviewed frameworks can be summarized as:

  • Reduce hazard,
  • Reduce exposure,
  • Use the best available information,
  • Ensure transparency in methods, criteria, and data used,
  • Identify and mitigate trade-offs, and
  • Take a flexible, iterative approach.



The BizNGO CAAP (Rossi et al. 2012) builds upon many existing frameworks, including: the Lowell Center for Sustainable Production's Alternatives Assessment Framework (Rossi et al. 2006); the U.S. Environmental Protection Agency Design for the Environment program's Alternatives Assessment framework (EPA 2014c); the United Nations Environment Program Persistent Organic Pollutants Review Committee's “General guidance on considerations related to alternatives and substitutes for listed persistent organic pollutants and candidate chemicals” (UNEP 2009); the methodology derived from the University of Massachusetts at Lowell's Toxic Use Reduction Institute's (TURI) 2006 Five Chemicals Alternatives Assessment study (TURI 2006a); and the Interstate Chemicals Clearinghouse's (IC2) Safer Alternatives Assessment Wiki (IC2 2014).


California's 2008 Safer Consumer Product Regulations (California's Assembly Bill 1879, or CAB 1879). The regulations took effect on October 1, 2013. Article 5 (California 1879 article 5) codifies the state's approach to safer chemical substitutions.


Classification (or benchmarking) tools provide threshold values for toxicological end points of interest, for evaluating data about effects of chemicals. These tools often result in assignment of a score (e.g., low, medium, high) that can be used to compare alternatives.

Copyright 2014 by the National Academy of Sciences. All rights reserved.
Bookshelf ID: NBK253958


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