CSS Mixtures RFA_Clean (2).pdf

COVID-19 Update: EPA is providing flexibilities to applicants experiencing challenges related to COVID-19. Please see the Flexibilities Available to Organizations Impacted by COVID-19 clause in Section IV of EPA’s Solicitation Clauses.

OVERVIEW INFORMATION

U.S. Environmental Protection Agency Office of Science Advisor, Policy and Engagement Office of Research and Development Science to Achieve Results (STAR) Program

DEVELOPMENT OF INNOVATIVE APPROACHES TO

ASSESS THE TOXICITY OF CHEMICAL MIXTURES

This is the initial announcement of this funding opportunity.

Funding Opportunity Numbers:

EPA-G2022-STAR-A1, Development of Innovative Approaches to Assess the Toxicity of Chemical Mixtures EPA-G2022-STAR-A2, Early Career: Development of Innovative Approaches to Assess the Toxicity of Chemical Mixtures

Catalog of Federal Domestic Assistance (CFDA) Number: 66.509

Solicitation Opening Date: October 8, 2021 Solicitation Closing Date: December 8, 2021: 11:59:59 pm Eastern Time

Table of Contents

SUMMARY OF PROGRAM REQUIREMENTS

Synopsis of Program Award Information Eligibility Information Application Materials Agency Contacts

I. FUNDING OPPORTUNITY DESCRIPTION

A. Introduction

B. Background C. Authority and Regulations D. Specific Areas of Interest/Expected Outputs and Outcomes E. References F. Special Requirements

II. AWARD INFORMATION

III. ELIGIBILITY INFORMATION

https://www.epa.gov/grants/epa-solicitation-clauses

A. Eligible Applicants B. Cost Sharing C. Other

IV. APPLICATION AND SUBMISSION INFORMATION

A. Grants.gov Submittal Requirements and Limited Exception Procedures B. Application Package Information C. Content and Form of Application Submission D. Submission Dates and Times E. Funding Restrictions F. Submission Instructions and Other Submission Requirements

V. APPLICATION REVIEW INFORMATION

A. Peer Review B. Relevancy Review C. Past Performance History Review D. Human Subjects Research Statement (HSRS) Review E. Evaluation of the Scientific Data Management Plan F. Funding Decisions G. Additional Provisions for Applicants Incorporated into the Solicitation

VI. AWARD ADMINISTRATION INFORMATION

A. Award Notices B. Disputes C. Administrative and National Policy Requirements

VII. AGENCY CONTACTS

For Updates and Additional Information (https://www.epa.gov/research-grants/research-funding-opportunities) Access Standard STAR Forms (https://www.epa.gov/research-grants/research-funding-opportunities-how-apply-and-required-forms) View research awarded under previous solicitations (https://www.epa.gov/research-grants/research-grant-areas)

SUMMARY OF PROGRAM REQUIREMENTS

Synopsis of Program:

This Request for Applications (RFA) solicits research focused on the development and evaluation of innovative methods and approaches to inform human health risk assessment of environmental chemical mixtures. Because most of the human chemical body burden involves concurrent or sequential exposures to mixtures of chemicals, methods to make better-informed, timelier evaluations of chemical mixtures of known, or partially-known, composition have long been needed. A challenge in conducting mixtures assessment is the lack of useful hazard and dose response data and other information on chemical mixtures. Potential chemical mixtures exposures of public health concern typically encountered in environmental media may include classes or subclasses of compounds (for example, per- and polyfluoroalkyl substances [PFAS], phthalates, polycyclic aromatic hydrocarbons [PAHs], disinfection by-products [DBPs]), or any other well-characterized mixtures. Applications are being sought that propose approaches and strategies that integrate in vitro, in silico, and/or non-mammalian in vivo methods that can https://www.epa.gov/research-grants/research-funding-opportunities https://www.epa.gov/research-grants/research-funding-opportunities https://www.epa.gov/research-grants/research-funding-opportunities-how-apply-and-required-forms https://www.epa.gov/research-grants/research-funding-opportunities-how-apply-and-required-forms https://www.epa.gov/research-grants/research-grant-areas https://www.epa.gov/research-grants/research-grant-areas contribute to decision-making science associated with toxicity evaluation and human health assessment of chemical mixtures.

This solicitation provides the opportunity for the submission of applications for projects that may involve human subjects research. Human subjects research supported by the EPA is governed by EPA Regulation 40 CFR Part 26 (Protection of Human Subjects). This includes the Common Rule at subpart A and prohibitions and additional protections for pregnant women and fetuses, nursing women, and children at subparts B, C, and D. Research meeting the regulatory definition of intentional exposure research found in subpart B is prohibited by that subpart in pregnant women, nursing women, and children. Research meeting the regulatory definition of observational research found in subparts C and D is subject to the additional protections found in those subparts for pregnant women and fetuses (subpart C) and children (subpart D). All applications must include a Human Subjects Research Statement (HSRS, as described in Section IV.C.6.c of this solicitation), and if the project involves human subjects research, it will be subject to an additional level of review prior to funding decisions being made as described in Sections V.D and V.F of this solicitation.

Guidance and training for investigators conducting EPA-funded research involving human subjects may be obtained here:

https://www.epa.gov/osa/basic-information-about-human-subjects-research-0 https://www.ecfr.gov/cgi-bin/text-idx?tpl=/ecfrbrowse/Title40/40cfr26_main_02.tpl

In addition to regular awards, this solicitation includes the opportunity for early career awards.

The purpose of the early career award is to fund research projects smaller in scope and budget by early career PIs. It is expected that the majority of the research will be performed by early career investigators. Further, it is expected that significant resources will be allotted to early career investigators to perform the research. Please see Section III of this Request for Applications (RFA) for details on the early career eligibility criteria.

Award Information:

Anticipated Type of Award: Grant or cooperative agreement Estimated Number of Awards: Approximately 6 awards, approximately 4 regular and approximately 2 early career awards. EPA intends to award 4 regular applications and 2 early career applications (as defined in Section III.A). This is an estimate and is subject to change based on funding levels, the quality of applications received, and other applicable considerations.

See Section V.F. Funding Decisions for additional information.

Anticipated Funding Amount: Approximately $4.2 million total for all awards Potential Funding per Award: Up to a total of $750,000 per regular award, and up to a total of $600,000 per early career award, including direct and indirect costs, with a maximum duration of 3 years. Cost-sharing is not required. Applications with budgets exceeding the total award limits will not be considered.

Eligibility Information:

Public and private nonprofit institutions/organizations, public and private institutions of higher education, and hospitals located in the U.S. and its territories or possessions; state and local governments; Federally Recognized Indian Tribal Governments; and U.S. territories or https://www.epa.gov/osa/basic-information-about-human-subjects-research-0 https://www.ecfr.gov/cgi-bin/text-idx?tpl=/ecfrbrowse/Title40/40cfr26_main_02.tpl possessions are eligible to apply. Special eligibility criteria apply to the early career award portion of this RFA. See full announcement for more details.

Application Materials:

To apply under this solicitation, use the application package available at Grants.gov (for further submission information see Section IV.F. “Submission Instructions and other Submission Requirements”). Note: With the exception of the current and pending support form (available at https://www.epa.gov/research-grants/research-funding-opportunities-how-apply-and-required-forms), all necessary forms are included in the electronic application package. Make sure to include the current and pending support form in your Grants.gov submission.

If your organization is not currently registered with Grants.gov, you need to allow approximately one month to complete the registration process. Please note that the registration process also requires that your organization have a DUNS number and a current registration with the System for Award Management (SAM) and the process of obtaining both could take a month or more.

Applicants must ensure that all registration requirements are met in order to apply for this opportunity through Grants.gov and should ensure that all such requirements have been met well in advance of the submission deadline. This registration, and electronic submission of your application, must be performed by an authorized representative of your organization.

If you do not have the appropriate internet access to utilize the Grants.gov application submission process for this solicitation, see Section IV.A below for additional guidance and instructions.

Agency Contacts:

Technical Contact: Hayley Aja; phone: 202-564-6427; email: aja.hayley@epa.gov Eligibility Contact: Ron Josephson; phone: 202-564-7823; email: josephson.ron@epa.gov Electronic Submissions Contact: Debra M. Jones; phone: 202-564-7839; email:

jones.debram@epa.gov

I. FUNDING OPPORTUNITY DESCRIPTION

A. Introduction This solicitation seeks research projects aimed at the development of methods and models to inform human health assessment of chemical mixtures. The chemical composition of candidate mixtures can be known, or partially known, but must be justified, described, characterized (in terms of component members and proportions), and reproducible (including component concentrations and proportions). Applications proposing research to develop or refine methods and models, and to assess their performance and reliability that improve the ability to investigate mixtures toxicology are solicited. In addition, innovative research to develop or refine in vitro, in silico (computational), or non-mammalian in vivo (such as zebrafish) methods that can contribute to decision-making science associated with the assessment of chemical mixtures encountered in the environment is sought. Potential chemical mixtures to investigate may be representative of classes and subclasses of compounds (for example, PFAS, phthalates, PAHs, DBPs, or other well-described mixtures). Approaches are needed to qualitatively characterize and quantify https://www.epa.gov/research-grants/research-funding-opportunities-how-apply-and-required-forms https://www.epa.gov/research-grants/research-funding-opportunities-how-apply-and-required-forms mailto:aja.hayley@epa.gov mailto:josephson.ron@epa.gov mailto:jones.debram@epa.gov hazards and associated human health risks of exposures to chemical mixtures found in environmental media.

The Science to Achieve Results (STAR) Program’s goal is to stimulate and support scientific and engineering research that advances EPA’s mission to protect human health and the environment.

It is a competitive, peer-reviewed, extramural research program that provides access to the nation’s best scientists and engineers in academic and other nonprofit research institutions.

STAR funds research on the environmental and public health effects of air quality, environmental changes, water quality and quantity, hazardous waste, toxic substances, and pesticides.

In addition to regular awards, this solicitation includes the opportunity for early career awards.

The purpose of the early career award is to fund research projects smaller in scope and budget by early career PIs. Please see Section III of this RFA for details on the early career eligibility criteria.

EPA recognizes that it is important to engage all available minds to address the environmental challenges the Nation faces. At the same time, EPA seeks to expand the environmental conversation by including members of communities which may have not previously participated in such dialogues to participate in EPA programs. For this reason, EPA strongly encourages all eligible applicants identified in Section III, including minority serving institutions (MSIs), to apply under this opportunity.

For purposes of this solicitation, the following are considered MSIs:

1. Historically Black Colleges and Universities, as defined by the Higher Education Act (20 U.S.C. § 1061(2)). A list of these schools can be found at Historically Black Colleges and Universities;

2. Tribal Colleges and Universities (TCUs), as defined by the Higher Education Act (20 U.S.C. § 1059c(b)(3) and (d)(1)). A list of these schools can be found at American Indian Tribally Controlled Colleges and Universities;

3. Hispanic-Serving Institutions (HSIs), as defined by the Higher Education Act (20 U.S.C. § 1101a(a)(5)). A list of these schools can be found at Hispanic-Serving Institutions;

4. Asian American and Native American Pacific Islander-Serving Institutions; (AANAPISIs), as defined by the Higher Education Act (20 U.S.C. § 1059g(b)(2)). A list of these schools can be found at Asian American and Native American Pacific Islander-Serving Institutions; and

5. Predominately Black Institutions (PBIs), as defined by the Higher Education Act of 2008, 20 U.S.C. 1059e(b)(6). A list of these schools can be found at Predominately Black Institutions.

B. Background Human and environmental receptors are continually exposed to chemicals present in environmental media (i.e., air, water, soil, food, and products in commerce). Extensive https://sites.ed.gov/whhbcu/one-hundred-and-five-historically-black-colleges-and-universities/ https://sites.ed.gov/whhbcu/one-hundred-and-five-historically-black-colleges-and-universities/ https://sites.ed.gov/whiaiane/tribes-tcus/tribal-colleges-and-universities/ https://sites.ed.gov/whiaiane/tribes-tcus/tribal-colleges-and-universities/ https://sites.ed.gov/hispanic-initiative/hispanic-serving-institutions-hsis/ https://www.google.com/maps/d/viewer?mid=1XVkOWKMDORm53pvU0L8EPsrJC94&msa=0&ie=UTF8&t=m&z=3&source=embed&ll=40.58644586187277%2C-148.28228249999984 https://www.google.com/maps/d/viewer?mid=1wlIi3j7gtlNq_w-0NKAb2bF2VmY&ie=UTF&msa=0&ll=37.35160769312532%2C-96.17229800000001&z=4 biomonitoring has established that all human populations are concurrently exposed to multiple chemicals (de Rosa, 2004). Due to the thousands of chemicals with minimal risk assessment-relevant information currently in commerce, combined with the near infinite number of possible component combinations, the assessment of chemical mixtures remains challenging (Bopp, 2019; Gibson, 2019).

Assessment of chemical mixtures has typically relied on the availability of information obtained from traditional experimental animal studies (e.g., National Toxicology Program 90 day or 2-year bioassays) and/or human epidemiological exposure-response data on individual component chemicals (Marshall, 2013; Hamra, 2018). Current approaches to evaluate chemical mixtures toxicity uses this type of data to assess only those constituents known to be in a mixture (Lasch, 2020). Whole mixtures toxicity data (including mixtures sufficiently similar for comparison) is rarely available for environmentally relevant chemicals. As such, component-based mixture assessment approaches are key to interpreting potential joint toxicity of chemicals. Two classically used methods for this are concentration addition (CA) (i.e., Dose Addition [DA]), and independent action (IA) (i.e., response addition) (U.S. EPA, 1986).

Research to evaluate in vitro, in silico, in vivo (i.e., alternative non-mammalian species such as zebrafish) methods for application in human health risk assessment of chemical mixtures encountered in the environment is sought. The performance and reliability of any new methods should be robust enough to help replace, reduce, and refine animal use (i.e., the 3Rs). Research to garner concentration-response data could potentially inform mixtures toxicity and assessment in a more rapid, flexible, and animal sparing manner. Research to identify ways to better integrate and utilize New Approach Methodology (NAM) data to (1) inform data-driven grouping, subgrouping, etc. of mixture components; and (2) leverage the universe of NAMs data to facilitate mixtures Dose-Response analyses (i.e., DA vs. IA, etc.), is key to advancing the science of mixtures risk assessment (U.S. EPA, 2021a; U.S. EPA, 2014; U.S. EPA, 2003).

Methods may include NAM platforms such as toxicogenomics, chemo- and bioinformatics (e.g., structure activity relationships, read-across, data mining techniques) and in vitro methods (e.g., cell-based bioactivity screening assays). Due to their lower cost and higher throughput, NAMs and alternative animal models have emerged as a potential approach to substantially advance mixtures risk assessment (Blackwell et al. 2019; Geier et al. 2018; Hayes et al. 2020; U.S. EPA 2006; U.S. EPA, 2018; Hayes, 2019; Hsieh, 2021). Generation of computational methods, or novel mathematical and statistical models that leverage NAM and/or experimental animal or epidemiological data for chemical mixtures may help facilitate more rapid evaluations of chemical mixture hazard and dose-response (ICCVAM, 2018; U.S. EPA, 2021b; Sobus, 2018).

A challenge in the assessment of mixtures is linking a given health effect back to a cocktail of chemicals of often highly varying speciation (e.g., degradants, metabolites parents) and proportions. Such linkages between a given health effect back to a cocktail of chemicals of often highly varying speciation could provide fundamental information for the greater use of predictive approaches in risk assessment, particularly if they can correlate NAMs data with traditionally sourced data of chemical mixtures’ components. Once internalized by an exposed individual or population, chemical mixtures potentially undergo diverse toxicokinetic processes in different organ/tissue/compartments and may ultimately result in different health effects.

https://doi.org/10.1177/1091581820905088 https://doi.org/10.1177/1091581820905088

Important design considerations have been identified when planning toxicology tests for chemical mixtures (Rider et al. 2018; NIEHS, 2015). Testing should include evaluation of mixture components at concentrations in the low-response region of the dose response curve, reflecting levels of contaminants typically measured in environmental media or exposure rates with components at proportions typically encountered in environmental media. The concentration-response evaluated should consider that higher dose levels are often needed to increase certainty in the parameters of dose-response models. Components that are not detected or assessed using traditional testing methods may comprise part of an environmental mixture and should be included where possible (Ruyle et al., 2021). Finally, the statistical power of a study regime should be considered in the low response region. Conclusions regarding consistency with or deviation from additivity requires a clear, appropriately referenced definition of the type of additivity under investigation. Experimental results can then be expressed as consistent with (i.e., no detectable deviation from additivity) or inconsistent with previous results. Due to the persistent lack of whole-mixture data, component-based mixture assessment approaches are key to interpreting potential joint toxicity of chemicals (Parvez, 2017). Traditional assay-based hazard and dose response are rarely available for informing membership of mixture chemicals in one or more signal transduction pathways leading to apical health effects/outcomes.

C. Authority and Regulations

The authorities for this RFA and resulting awards are contained in the Toxic Substances Control Act, 15 U.S.C. 2609, Section 10, as amended by P.L. 106-74 and the Federal Insecticide, Fungicide, and Rodenticide Act, 7 U.S.C. 136r, Section 20, as amended by P.L. 106-74.

For research with an international aspect, the above statutes are supplemented, as appropriate, by the National Environmental Policy Act, Section 102(2)(F).

Note that a project’s focus is to consist of activities within the statutory terms of EPA’s financial assistance authorities; specifically, the statute(s) listed above. Generally, a project must address the causes, effects, extent, prevention, reduction and elimination of air pollution, water pollution, solid/hazardous waste pollution, toxic substances control or pesticide control depending on which statute(s) is listed above. Further note applications dealing with any aspect of or related to hydraulic fracking will not be funded by EPA through this program.

Additional applicable regulations include: 2 CFR Part 200, 2 CFR Part 1500, and 40 CFR Part 40 (Research and Demonstration Grants).

D. Specific Areas of Interest/Expected Outputs and Outcomes Note to applicant: The term “output” means an environmental activity, effort, and/or associated work products related to an environmental goal or objective, that will be produced or provided over a period of time or by a specified date. The term “outcome” means the result, effect or consequence that will occur from carrying out an environmental program or activity that is related to an environmental or programmatic goal or objective.

The activities to be funded under this announcement support EPA’s FY 2018-22 Strategic Plan (https://www.epa.gov/planandbudget/strategicplan). Activities to be funded under this announcement support Goal 3: Greater Certainty, Compliance, and Effectiveness, Objective 3.3:

Prioritize Robust Science, of EPA’s FY 2018-22 Strategic Plan. All applications must be for projects that support the goal and objective identified above. Awards made under this announcement will further EPA’s priorities supporting robust science for Chemical Safety.

The proposed research awards support the STAR Program’s goal of stimulating and supporting scientific and engineering research that advances EPA’s mission to protect human health and the environment in the area of chemical safety by supporting measures and strategies for use by state, tribal, and local programs and communities to reduce chemical pollution.

EPA also requires that grant applicants adequately describe environmental outputs and outcomes to be achieved under assistance agreements (see EPA Order 5700.7A1, Environmental Results under Assistance Agreements, https://www.epa.gov/grants/epa-order-57007a1-epas-policy-environmental-results-under-epa-assistance-agreements). Applicants must include specific statements describing the environmental results of the proposed project in terms of well-defined outputs and, to the maximum extent practicable, well-defined outcomes that will demonstrate how the project will contribute to the priorities described above.

This RFA seeks to fund research focusing on improving the quantitative evaluation of risks posed by chemical mixtures in the environment. The focus should be on the development and improvement, evaluation, and integration of predictive toxicology methods to evaluate environmental chemical mixtures. Potential chemical study mixtures may include representative structurally-related chemical groups, or more broadly, mixtures co-located in the environment (regardless of structural lineage or membership). These may include PFAS, phthalates, PAHs, DBPs or other well-characterized mixtures. The environmental mixtures evaluated could include whole mixtures which may or may not be comprehensively characterized chemically, or defined mixtures with detailed description of analytical composition. The interest is in environmentally relevant exposures to well-characterized mixtures. Applicants should consider the mixture characteristics best suited for their proposed research and specify how their proposed mixture(s) meet these characteristics. Applicants are encouraged to consider potential end users of methods developed, demonstrated, and applied in this research. Potential users include state, tribal, local and regional monitoring agencies, industries, communities as well as other scientific research groups. Researchers are encouraged to consider how new techniques developed in these projects can be standardized or made user-friendly for the assessment of risks posed by chemical mixtures.

Research Areas:

Applications should address at least one of the following two research areas. Applications that do not address at least one of research areas listed below may not be rated as highly as those that do.

1. Development and application of approaches to establish qualitative membership of chemical mixture components into toxicity pathway groupings in order to quantitatively evaluate their potential joint toxicity.

Applications in this specific area should focus on at least one of the following 3 sub-areas:

https://www.epa.gov/planandbudget/strategicplan https://www.epa.gov/grants/epa-order-57007a1-epas-policy-environmental-results-under-epa-assistance-agreements https://www.epa.gov/grants/epa-order-57007a1-epas-policy-environmental-results-under-epa-assistance-agreements

a) Identification and integration of NAM-based data (e.g., in vitro cell bioactivity;

toxicogenomics; structure-activity) to inform a chemical/biological strategy for assigning membership of mixture component chemicals into (sub)groupings for assessment of joint toxicity.

b) Interrogation of the comparability of joint toxicity (e.g., additivity, non-additivity) in chemical mixtures, as a function of component dose/proportions, across traditional assay-based vs. NAM data. A study design could entail comparison of a well characterized mixture of chemicals that has been evaluated using traditional bioassay data with the same mixture at the same component concentrations/proportions as in vivo study(ies), and/or a priori standardized exposure concentration (for example, individual component chemical effect dose 50%; ED50) or across a range of concentrations or doses to examine consistency in the measures of joint toxicity evaluated in a NAM approach. The objective would include examining the predictivity of the NAM data for overall mixture risk based on different assumptions of joint interaction (e.g., dose and response additivity).

c) Generation of novel computational methods and mathematical and statistical models that leverage NAM and/or, experimental animal, or epidemiological data for chemical mixtures hazard and dose-response assessment.

2. Development of tools useful for the examination of chemical mixture toxicity across different levels of biological organization.

Applications in this specific area should focus on the development of tools or methods related to the diversity of data types collected from NAMs focused on a variety of tissue types or levels of biological organization that can be integrated in a manner useful to hazard and/or risk assessment. Specifically, research is needed on how NAM data/outputs on differing levels of biological organization (e.g., from cellular to whole organism level) intended to discern toxicity or bioactivity of individual mixture components can relate back to their originating (i.e., exposure source) mixtures, and to final whole organism health effects. Basing exposure-response interpretations for those components adversely impacting target tissue(s) versus extrapolating back to the whole mixture at an external dose may prove useful.

Outputs and Outcomes

Potential outputs expected from the research funded under this RFA may include:

• Reports, presentations, and peer-reviewed journal publications describing the development, demonstration, and validation of mixtures toxicity methods and models.

• Web-based platforms or applications able to contribute data useful for mixtures-based hazard and dose-response assessments. These may include support of mathematical and statistical models.

• Methods and models that inform qualitative and quantitative assessment of real-world chemical mixtures.

• Solutions that integrate or correlate NAMs data with traditional bioassay-based data.

• Alternative methodologies for screening or prioritizing environmental mixtures.

Potential outcomes expected from the research funded under this RFA may include:

• Advancements in hazard assessments (including grouping strategies) of the multitude of chemicals considered in a mixtures risk context that will support state, local and tribal efforts in addressing contaminants of concern.

• Improved integration of multiple lines of evidence across assay/data type.

• Enhanced identification of commonalities among responses to chemical mixtures at different levels of biological organization which address the relevance of these levels and the responses to health outcomes (e.g., apical endpoints).

Innovation and Sustainability To the maximum extent practicable, research applications must embody innovation and sustainability. Innovation for the purposes of this RFA is defined as the process of making changes; a new method, custom or device. Innovative research can take the form of wholly new applications or applications that build on existing knowledge and approaches for new uses.

Research applications must include a discussion on how the proposed research is innovative (see Section IV.C.6.a). The goal of sustainability, derived from the U.S. National Environmental Policy Act of 1969 (NEPA), is to “create and maintain conditions, under which humans and nature can exist in productive harmony, that permit fulfilling the social, economic and other requirements of present and future generations.” Research applications must include a discussion on how the proposed research will seek sustainable solutions that protect the environment and strengthen our communities (see Section IV.C.6.a). Reviewers will draw from all of the above-mentioned innovation and sustainability definitions in the review/evaluation process of research applications (see Section V.A).

Glossary

• For the purposes of this solicitation, a chemical mixture is defined as “any combination of two or more chemical substances, regardless of source or of spatial or temporal proximity, that can influence the risk of chemical toxicity in the target population” (U.S.

EPA, 2000, 2000b, 1986). The Agency for Toxic Substances and Disease Registry (ATSDR) describes three origins of chemical mixtures in the environment (ATSDR, 2004). Mixtures originate as intentional mixtures that are developed and released as a mix of chemicals, including manufactured products such as brominated flame retardants, consumer products, pesticide formulations, and fuels. Incidental mixtures originate as a consequence of a process such as disinfection of drinking water or combustion. Finally, co-incidental mixtures consist of chemicals that coexist in the same medium due to their physical and chemical properties, although they may arise from different sources.

• For the purposes of this solicitation, a mixture risk assessment is the process of evaluating the available information to estimate health consequences from exposure to a particular chemical mixture; these health consequences can be characterized in terms of risk or in terms of comparisons of exposure to a health-based benchmark (i.e., a health hazard evaluation) (U.S. EPA, 2005).

• For the purposes of this solicitation, New Approach Methodology (NAM) is a broadly descriptive term for any non-animal technology, methodology or approach, or combination thereof that can be used to provide information on chemical hazard and risk assessment (U.S. EPA, 2021b).

• For the purposes of this solicitation, susceptibility refers to conditions of differential or heightened responses in an individual or population relative to that of another individual or population.

• For purposes of this solicitation, hazard is defined to be the nature of the adverse effect estimated for the exposed population, including some characterization of the expected severity, which also is consistent with past Agency guidance and practice (U.S. EPA, 2000).

• For purposes of this solicitation, joint toxicity is defined as an adverse effect mediated through the combined actions of two or more chemicals.

• For purposes of this solicitation, traditional bioassays data refers to median effective dose (ED50), relative potency factor (RPF), or toxic equivalency factor (TEF) values.

• For the purposes of this solicitation, biological organization refers to structures in nature defined by part-whole relationships, with things at higher levels being composed of things at the next lower level (e.g., from cellular to whole organism level).

Acronyms:

AOP; Adverse Outcome Pathways CA; Concentration Addition DA; Dose Addition DBP; Disinfection By-Products IA; Independent Action MOA; Mode Of Action NAM; New Approach Methodology PAHs; Polycyclic Aromatic Hydrocarbons PFAS; Per- and Polyfluoroalkyl Substances

E. References

1. de Rosa CT, El-Masri HA, Pohl H, Cibulas W, Mumtaz MM.J. 2004. “Implications of chemical mixtures in public health practice.” Toxicol Environ Health B Crit Rev 7(5):339-50. https://pubmed.ncbi.nlm.nih.gov/15371239/.

2. Bopp SK, KienzlerA, RicharzAN, vanderLinden SC, Paini A, ParissisN, et al. 2019.

“Regulatory assessment and risk management of chemical mixtures: challenges and ways forward.” Crit Rev Toxicol 49(2):174–189.

https://doi.org/10.1080/10408444.2019.1579169.

3. Elizabeth A Gibson, Jeff Goldsmith, Marianthi-Anna Kioumourtzoglou. 2019. “Complex Mixtures, Complex Analyses: An Emphasis on Interpretable Results.” Curr Environ Health Rep 6(2):53-61. https://pubmed.ncbi.nlm.nih.gov/31069725/.

4. Marshall S, Gennings C, Teuschler LK, Stork LG, Tornero-Velez R, Crofton KM, Rice GE. 2013. “An empirical approach to sufficient similarity: combining exposure data and mixtures toxicology data.” Risk Analysis 33(9): 1582-95.

https://pubmed.ncbi.nlm.nih.gov/23398277/.

https://pubmed.ncbi.nlm.nih.gov/15371239/ https://doi.org/10.1080/10408444.2019.1579169 https://pubmed.ncbi.nlm.nih.gov/?term=Gibson+EA&cauthor_id=31069725 https://pubmed.ncbi.nlm.nih.gov/?term=Goldsmith+J&cauthor_id=31069725 https://pubmed.ncbi.nlm.nih.gov/?term=Kioumourtzoglou+MA&cauthor_id=31069725 https://pubmed.ncbi.nlm.nih.gov/31069725/ https://pubmed.ncbi.nlm.nih.gov/23398277/

5. Hamra GB, Buckley JP. 2018. “Environmental exposure mixtures: questions and methods to address them.” Curr Epidemiol Rep 5(2): 160–5.

https://pubmed.ncbi.nlm.nih.gov/30643709/.

6. Lasch A, LichtensteinD, Marx-StoeltingP, BraeuningA, AlarcanJ. 2020. Mixture effects of chemicals: the difficulty to choose appropriate mathematical models for appropriate conclusions. EnvironPollut, 260:113953. https://doi.org/10.1016/j.envpol.2020.113953.

7. U.S. EPA. 1986. “Guidelines for the Health Risk Assessment of Chemical Mixtures.”

EPA/630/R-98/002. Available at https://www.epa.gov/risk/guidelines-health-risk-assessment-chemical-mixtures.

8. U.S. EPA. 2021a. “New Approach Methods Work Plan: Reducing Use of Animals in Chemical Testing.” Available at https://www.epa.gov/chemical-research/epa-new-approach-methods-work-plan-reducing-use-animals-chemical-testing.

9. U.S. EPA. 2014. “Framework for human health risk assessment to inform decision making.” Office of the Science Advisor, Risk Assessment Forum. EPA/100/R-14/001.

https://www.epa.gov/risk/framework-human-health-risk-assessment-inform-decision-making.

10. U.S. EPA. 2003. “Developing Relative Potency Factors for Pesticide Mixtures:

Biostatistical Analyses of Joint Dose Response.”

https://cfpub.epa.gov/ncea/risk/hhra/recordisplay.cfm?deid=66273.

11. Blackwell, Brett R., et al. 2018 "Potential toxicity of complex mixtures in surface waters from a nationwide survey of United States streams: identifying in vitro bioactivities and causative chemicals." Environmental science & technology 53.2: 973-983.

https://doi.org/10.1021/acs.est.8b05304.

12. Geier MC, Minick DJ, Truong L, Tilton S, Pande P, Anderson KA, et al. 2018.

Systematic developmental neurotoxicity assessment of a representative PAH superfund mixture using zebrafish.” Toxicol Appl Pharmacol, 354:115–125.

https://doi.org/10.1016/j.taap.2018.03.029.

13. Hayes AW, Muriana A, Alzualde A, Fernandez DB, Iskandar A, PeitschMC, et al. 2020.

“Alternatives to animal use in risk assessment of mixtures.” Int JToxicol 39(2):165–172,.

https://doi.org/10.1177/1091581820905088.

14. U.S. EPA. 2006. “Considerations for Developing Alternative Health Assessment Approaches for Addressing Multiple Chemicals, Exposures, and Effects.” EPA/600/R- 06/014A. https://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=149983.

15. U.S. EPA. 2018. “Office of Research and Development (ORD) Chemical Safety for Sustainability Strategic Research Action Plan 2019-2022.”

https://www.epa.gov/research/chemical-safety-sustainability-strategic-research-action-plan-2019-2022.

16. A Wallace Hayes, Roman Li, Julia Hoeng, Anita Iskandar, Manuel C Peistch, Michael L Dourson. 2019. “New approaches to risk assessment of chemical mixtures.” Toxicology Research and Application. https://doi.org/10.1177/2397847318820768.

17. Hsieh NH, Chen Z, Rusyn I and Chiu WA. 2021 “Risk Characterization and Probabilistic Concentration–Response Modeling of Complex Environmental Mixtures Using New Approach Methodologies (NAMs) Data from Organotypic in Vitro Human Stem Cell Assays.” Environmental Health Perspectives 129(1).

https://ehp.niehs.nih.gov/doi/10.1289/EHP7600?url_ver=Z39.88- 2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed.

https://pubmed.ncbi.nlm.nih.gov/30643709/ https://doi.org/10.1016/j.envpol.2020.113953 https://www.epa.gov/risk/guidelines-health-risk-assessment-chemical-mixtures https://www.epa.gov/risk/guidelines-health-risk-assessment-chemical-mixtures https://www.epa.gov/chemical-research/epa-new-approach-methods-work-plan-reducing-use-animals-chemical-testing https://www.epa.gov/chemical-research/epa-new-approach-methods-work-plan-reducing-use-animals-chemical-testing https://www.epa.gov/risk/framework-human-health-risk-assessment-inform-decision-making https://www.epa.gov/risk/framework-human-health-risk-assessment-inform-decision-making https://cfpub.epa.gov/ncea/risk/hhra/recordisplay.cfm?deid=66273 https://doi.org/10.1021/acs.est.8b05304 https://doi.org/10.1016/j.taap.2018.03.029 https://doi.org/10.1177/1091581820905088 https://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=149983 https://www.epa.gov/research/chemical-safety-sustainability-strategic-research-action-plan-2019-2022 https://www.epa.gov/research/chemical-safety-sustainability-strategic-research-action-plan-2019-2022 https://doi.org/10.1177/2397847318820768 https://ehp.niehs.nih.gov/doi/10.1289/EHP7600?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed https://ehp.niehs.nih.gov/doi/10.1289/EHP7600?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed

18. ICCVAM. 2018. “A strategic roadmap for establishing new approaches to evaluate the safety of chemicals and medical products in the United States.”

https://ntp.niehs.nih.gov/iccvam/docs/roadmap/iccvam_strategicroadmap_january2018_d ocument_508.pdf.

19. U.S.EPA. 2021b. CompTox Chemicals Dashboard.

https://comptox.epa.gov/dashboard/chemical_lists.

20. Rider, Cynthia V., and Jane Ellen Simmons, eds. 2018 “Chemical Mixtures and Combined Chemical and Nonchemical Stressors: Exposure, Toxicity, Analysis, and Risk.” https://link.springer.com/content/pdf/10.1007/978-3-319-56234-6.pdf.

21. NIEHS. 2015. “Statistical Approaches for Assessing Health Effects of Environmental Chemical Mixtures in Epidemiology Studies.”

http://www.niehs.nih.gov/about/events/pastmtg/2015/statistical.

22. Ruyle, Bridger J., et al. 2021 "Isolating the AFFF Signature in Coastal Watersheds Using Oxidizable PFAS Precursors and Unexplained Organofluorine." Environmental Science & Technology 55.6: 3686-3695. https://doi.org/10.1021/acs.est.0c07296.

23. Parvez S, Rice GE, Teuschler LK, Simmons JE, Speth TF, Richardson SD, Miltner RJ, Hunter ES 3rd, Pressman JG, Strader LF, Klinefelter GR, Goldman JM, Narotsky MG.

2017. “Method to assess component contribution to toxicity of complex mixtures:

Assessment of puberty acquisition in rats exposed to disinfection byproducts.” J Environ Sci (China), 58:311-321. https://pubmed.ncbi.nlm.nih.gov/28774622/.

24. U.S. EPA. 2000. “Risk Characterization Handbook.” EPA Science Policy Council.

https://www.epa.gov/sites/default/files/2015- 10/documents/osp_risk_characterization_handbook_2000.pdf.

25. U.S. EPA. 2000b. “Supplementary Guidance for Conducting Health Risk Assessment of Chemical Mixtures. EPA Risk Assessment Forum.” EPA/630/R-00/002.

https://cfpub.epa.gov/ncea/raf/pdfs/chem_mix/chem_mix_08_2001.pdf.

26. ATSDR. 2004. “Framework for Assessing Health Impacts of Multiple Chemicals and Other Stressors (Update).” U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, Agency for Toxic Substances Disease Registry.

http://www.atsdr.cdc.gov/interactionprofiles/IP-ga/ipga.pdf.

27. U.S. EPA. 2005. “Human Health Risk Assessment Protocol for Hazardous Waste Combustion Facilities, Final.” EPA520-R-05-006.

https://archive.epa.gov/epawaste/hazard/tsd/td/web/html/risk.html.

28. U.S. EPA. 2021b. Assessing and Managing Chemicals under TSCA: Alternative Test Methods and Strategies to Reduce Vertebrate Animal Testing.

https://www.epa.gov/assessing-and-managing-chemicals-under-tsca/alternative-test-methods-and-strategies-reduce#implementation.

29. Sobus, J.R., Wambaugh, J.F., Isaacs, K.K. et al. 2018. “Integrating tools for non-targeted analysis research and chemical safety evaluations at the US EPA.” J Expo Sci Environ Epidemiol 28, 411–426. https://doi.org/10.1038/s41370-017-0012-y.

F. Special Requirements

It is EPA Policy to ensure that the results of EPA-funded extramural scientific research are accessible to the public to the greatest extent feasible consistent with applicable law; policies and Orders; the Agency’s mission; resource constraints; and U.S. national, homeland and economic https://ntp.niehs.nih.gov/iccvam/docs/roadmap/iccvam_strategicroadmap_january2018_document_508.pdf https://ntp.niehs.nih.gov/iccvam/docs/roadmap/iccvam_strategicroadmap_january2018_document_508.pdf https://ntp.niehs.nih.gov/iccvam/docs/roadmap/iccvam_strategicroadmap_january2018_document_508.pdf https://ntp.niehs.nih.gov/iccvam/docs/roadmap/iccvam_strategicroadmap_january2018_document_508.pdf https://comptox.epa.gov/dashboard/chemical_lists https://link.springer.com/content/pdf/10.1007/978-3-319-56234-6.pdf http://www.niehs.nih.gov/about/events/pastmtg/2015/statistical https://doi.org/10.1021/acs.est.0c07296 https://pubmed.ncbi.nlm.nih.gov/28774622/ https://www.epa.gov/sites/default/files/2015-10/documents/osp_risk_characterization_handbook_2000.pdf https://www.epa.gov/sites/default/files/2015-10/documents/osp_risk_characterization_handbook_2000.pdf https://cfpub.epa.gov/ncea/raf/pdfs/chem_mix/chem_mix_08_2001.pdf http://www.atsdr.cdc.gov/interactionprofiles/IP-ga/ipga.pdf https://archive.epa.gov/epawaste/hazard/tsd/td/web/html/risk.html https://www.epa.gov/assessing-and-managing-chemicals-under-tsca/alternative-test-methods-and-strategies-reduce#implementation https://www.epa.gov/assessing-and-managing-chemicals-under-tsca/alternative-test-methods-and-strategies-reduce#implementation https://doi.org/10.1038/s41370-017-0012-y security. This entails maximizing, at no charge, access by the public to peer-reviewed, scientific research journal publications or associated author manuscripts, and their underlying digital research data, created in whole or in part with EPA funds, while protecting personal privacy;

recognizing proprietary interests, confidential business information and intellectual property rights; and avoiding significant negative impact on intellectual property rights, innovation and U.S. competitiveness. EPA’s Policy for Increasing Access to Results of EPA-Funded Extramural Scientific Research may be accessed at: https://www.epa.gov/research/non-epa-researcher-requirements. Terms and conditions implementing this policy may be accessed at:

https://www.epa.gov/research/non-epa-researcher-requirements.

Applications submitted under this announcement shall include a Scientific Data Management Plan (SDMP) that addresses public access to EPA-funded scientific research data. See the SDMP clause in Section IV for details on the content of an SDMP. Applicants will also be asked to provide past performance information on whether journal publications or associated author manuscripts, and the associated underlying scientific research data and metadata, under prior assistance agreements were made publicly accessible. These items will be evaluated prior to award.

Reasonable, necessary and allocable costs for data management and public access as discussed in EPA’s Policy for Increasing Access to Results of EPA-Funded Extramural Scientific Research, may be included in extramural research applications and detailed in the budget justification described in Section IV.

Agency policy and ethical considerations prevent EPA technical staff and managers from providing applicants with information that may create an unfair competitive advantage.

Consequently, EPA employees will not review, comment, advise and/or provide technical assistance to applicants preparing applications in response to EPA RFAs. EPA employees cannot endorse any particular application.

Multiple Investigator applications may be submitted as: (1) a single Lead Principal Investigator (PI) application with Co-PI(s) or (2) a Multiple PI application (with a single Contact PI). If you choose to submit a Multiple PI application, you must follow the specific instructions provided in Sections IV. and V. of this RFA. For further information, please see the EPA Implementation Plan for Policy on Multiple Principal Investigators (https://www.epa.gov/research-grants/research-grants-guidance-and-policies).

Please note: Early career awards will not accommodate a Multiple PI application. Early career awards shall be submitted as a single Lead PI application. Special eligibility criteria apply to the early career portion of this RFA. Please see Section III of this RFA for details on the early career eligibility criteria. The application must include an early career verification (see “Early Career Verification” in Section IV.C.6.e).

This solicitation provides the opportunity for the submission of applications for projects that may involve human subjects research. All applications must include a Human Subjects Research Statement (HSRS; described in Section IV.C.6.c of this solicitation). If the project involves https://www.epa.gov/research/non-epa-researcher-requirements https://www.epa.gov/research/non-epa-researcher-requirements https://www.epa.gov/research/non-epa-researcher-requirements human subjects research, it will be subject to an additional level of review prior to funding decisions being made as described in Sections V.D and V.F of this solicitation.

II. AWARD INFORMATION

It is anticipated that a total of approximately $4.2 million will be awarded under this announcement, depending on the availability of funds, quality of applications received and other applicable considerations. The EPA anticipates funding approximately 6 awards (4 regular and 2 early career) under this RFA. Requests for amounts in excess of a total of $750,000 per regular award, and in excess of a total of $600,000 per early career award, including direct and indirect costs, will not be considered. The total project period requested in an application submitted for this RFA may not exceed 3 years.

As stated above, EPA intends to award 4 regular applications and 2 early career applications (as defined in Section III.A). This is an estimate and is subject to change based on funding levels, the quality of applications received, and other applicable considerations. See Section V.F.

Funding Decisions for additional information.

The EPA reserves the right to reject all applications and make no awards, or make fewer awards than anticipated, under this RFA. The EPA reserves the right to make additional awards under this announcement, consistent with Agency policy, if additional funding becomes available after the original selections are made. Any additional selections for awards will be made no later than six months after the original selection decisions.

In appropriate circumstances, EPA reserves the right to partially fund applications by funding discrete portions or phases of proposed projects. If EPA decides to partially fund an application, it will do so in a manner that does not prejudice any applicants or affect the basis upon which the application, or portion thereof, was evaluated and selected for award, and therefore maintains the integrity of the competition and selection process.

EPA may award both grants and cooperative agreements under this announcement.

Under a grant, EPA scientists and engineers are not permitted to be substantially involved in the execution of the research. However, EPA encourages interaction between its own laboratory scientists and grant Principal Investigators after the award of an EPA grant for the sole purpose of exchanging information in research areas of common interest that may add value to their respective research activities. This interaction must be incidental rather than substantial to achieving the goals of the research under a grant. Interaction that is “incidental” does not involve resource commitments by EPA.

Where appropriate, based on consideration of the nature of the proposed project relative to the EPA’s intramural research program and available resources, the EPA may award cooperative agreements under this announcement.