Learn the Issues

Process for Developing Improved Cordwood Test Methods for Wood Heaters

Process for Developing Improved Cordwood Test Methods for Wood Heaters document

What You Can Do about Climate Change

Home page linking to pages with tips for fighting climate change at home, at the office, on the road and at school.

What is a HEPA filter?

HEPA is a type of pleated mechanical air filter that is common in portable air cleaners, also known as air purifiers. It is an acronym for " high efficiency particulate air" filter, as officially defined by the U.S. Department of Energy. This type of air filter can theoretically remove at…

• Last published: January 13, 2026

Soak Up the Rain: Rain Barrels

Find resources and learn how to install, use and maintain a rain barrel to collect rain water when it rains and help to reduce stormwater runoff from your property.

Exploration of Aging and Toxic Response Issues: Final Report

Most physiological functions undergo deterioration with increasing adult age and this deterioration undoubtedly increases vulnerability to harmful environmental agents.

Human Health Risk Assessment

This site will be linked off of the risk Microsite and will be where the 4 steps to HHRA, the guidelines to HHRA, links to models, tools, databases and HHRA examples.

Conducting a Human Health Risk Assessment

This page provides the step-by-step instructions to how the EPA conducts a human health risk assessment with additional links to models, tools, databases and related products.

Papers Addressing Scientific Issues in the Risk Assessment of Metals

To inform the consideration of metals properties, and to engage the external scientific community, the Agency commissioned external experts to lead the development of a series of issue papers.

Methods for Identifying a Default Cross-Species Scaling Factor (Rhomsberg, 2004)

Provides a rationale for selecting default cross-species extrapolation factors with which to scale oral doses across species for non-carcinogenic endpoints.

Antimicrobial Exposure Assessment Task Force II (AEATF II) Volume 5: Governing Document for a Multi-Year Antimicrobial Chemical Exposure Monitoring Program (interim draft document with changes)

This document describes the overall scope of the AEATF II program, demonstrates the need for additional human exposure monitoring data and explains the proposed methodology for the exposure monitoring studies proposed for conduct by the AEATF II.

External Review Draft: Harmonization in Interspecies Extrapolation: Use of BW 3/4 as Default Method in Derivation of the Oral RfD

Recommends procedures, inclusive of default procedures, that will be used to estimate oral exposures in terms of human equivalents for all toxicologic endpoints.

Issue Paper on the Human Health Effects of Metals

This paper discusses issues important to consider in developing a framework for performing human health assessments for exposure to metals and metal compounds

Antimicrobial Exposure Assessment Task Force II (AEATF II) Volume 5: Governing Document for a Multi-Year Antimicrobial Chemical Exposure Monitoring Program (interim draft document)

Describes the overall scope of the AEATF II program, demonstrates the need for additional human exposure monitoring data and explains the proposed methodology for the exposure monitoring studies proposed for conduct by the AEATF II.

Issue Paper on the Ecological Effects of Metals

A summary of biological and ecological responses to metals, and discuss the role of descriptive and predictive methods used to characterize effects of metals in risk assessment.

Issue Paper on the Environmental Chemistry of Metals

EPA has identified three types of regulatory risk assessments where information regarding speciation of metals is useful and desirable: national hazard/risk ranking and characterization, site-specific assessments, and National Regulatory Assessments.

Issue Paper on the Bioavailability and Bioaccumulation of Metals

The goal of this paper is to summarize the current and emerging state of the science supporting assessments of metal bioavailability and bioaccumulation in aquatic and terrestrial organisms.

SERC-TERC Updates: October 2024

SERC-TERC Updates: October 2024

SERC-TERC Updates: November 2024

SERC-TERC Updates: November 2024

Protect Your Private Well

this info-graphic provides on overview of the steps private well owners should take to protect the safety of their drinking water

Guidance on Petitioning for Sole Source Aquifer (SSA) Designation

Information on the EPA's Sole Source Aquifer (SSA) Designation Petitioner Guidance, to assist those interested in submitting SSA designation petitions to EPA regional offices