Dioxins

Policy and Guidance

Dioxins originate primarily as unwanted byproducts of industrial manufacturing and the incomplete combustion of materials containing carbon and chlorine. Consequently, they are regulated as a waste byproduct by various federal and state programs. According to EPA's 2013 draft update to An Inventory of Sources and Environmental Releases of Dioxin-Like Compounds, there was an approximate 74% reduction in the release of dioxin and dioxin-like compounds (PCDFs and select PCBs) to the circulating environment of the United States between 1987 and 2000. This reduction in environmental releases of dioxin-like compounds was attributed to stricter federal and state regulations, improvements in source technology, and advancements in the pollution control technologies specific to controlling dioxin discharges and releases.

Federal

Clean Air Act (CAA): 2,3,7,8-TCDD was one of the original 189 hazardous air pollutants named in the CAA. Companies whose operations have the potential to emit dioxins into the air must implement engineering measures to control these emissions.
Clean Water Act (CWA): Discharge of the wastewater containing PCDDs is regulated under the CWA National Pollutant Discharge Elimination System Permitting Program.
Resource Conservation and Recovery Act (RCRA): Requires wastes in waste codes F020 to F023 and F026 to F032 to be treated for dioxins before they can be disposed of in a secure landfill.
Safe Drinking Water Act (SDWA): The SDWA set a Maximum Contaminant Level (MCL) of 0.00000003 mg/L for dioxin (2,3,7,8-TCDD) in drinking water.
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA): CERCLA lists 2,3,7,8-TCDD as a hazardous substance with a one-pound reportable quantity.
National Oil and Hazardous Substances Pollution Contingency Plan (NCP): The NCP requires that applicable or relevant and appropriate requirements of other statutes and regulations be considered during a response action. Therefore, it is likely that a Superfund response action will need to conform to CAA, CWA, and RCRA applicable provisions relating to the response's potential release of dioxins to the air, surface water and land.
Emergency Planning and Community Right-to-Know Act of 1986 (EPCRA): On October 29, 1999, EPA promulgated a final rule (64 FR 58666) adding a category of dioxin and dioxin-like compounds to the list of toxic chemicals subject to the reporting requirements under section 313 of EPCRA. The Toxics Release Inventory: Guidance for Reporting the Dioxin and Dioxin-like Compounds Category contains guidance information specific to reporting dioxin and dioxin-like compounds to the Toxics Release Inventory (TRI).

Some states have set their own criteria for dioxins. Through EPA's links to the Health and Environmental Agencies of U.S. States and Territories, readers can search for the most recent information on dioxins in each state.

Adapted from:

40 CFR 261: Identification and Listing of Hazardous Waste
U.S. EPA, Office of Solid Waste.

40 CFR 300 National Oil and Hazardous Substances Pollution Contingency Plan
U. S. EPA, Office of Superfund Remediation and Technology Innovation.

40 CFR 302--Designation, Reportable Quantities, and Notification
U.S. EPA, Office of Solid Waste.

Emergency Planning and Community Right-to-Know Act - Section 313: Guidance for Reporting Toxic Chemicals within the Dioxin and Dioxin-like Compounds Category
U. S. EPA, Office of Information Analysis and Access. EPA-745-B-00-021. December 2000.

Federal Resources

Air

40 CFR Part 62: Federal Plan Requirements for Small Municipal Waste Combustion Units Constructed on or Before August 30, 1999; Final Rule
U.S. EPA. Federal Register, Vol 68 No 21, p 5144-5187, January 31, 2003.

Technical Support Document: Control of Emissions of Hazardous Air Pollutants from Motor Vehicles and Motor Vehicle Fuels
U.S. EPA, Office of Transportation and Air Quality. EPA 420-R-00-023, 195 pp, 2000.

Soil

Integrated Risk Information System (IRIS) Chemical Assessment Summary for 2,3,7,8 Tetrachlorodibenzo-p-dioxin (TCDD); CASRN 174601-6
U.S. EPA National Center for Environmental Assessment, 16 pp, Last revised February 17, 2012.

IRIS assessment provides the oral reference dose (RfD) for 2,3,7,8-TCDD and supporting information.

Fact Sheet on the Management of Dioxin Contaminated Soils
U.S. EPA, 28 pp, 2011

This fact sheet provides information on the disposal of dioxin-contaminated soil subject to RCRA Land Disposal Requirements (LDRs) as well as for contaminated soil not subject to RCRA LDRs.

User Guide - Uniform Federal Policy Quality Assurance Project Plan Template for Soils Assessment of Dioxin Sites
U.S. EPA, 112 pp, 2011

Template - Uniform Federal Policy Quality Assurance Project Plan for Soils Assessment of Dioxin Sites
99 pp

Statistical Support Document for the Development of Round 2 Biosolids Use or Disposal Regulations
U.S. EPA, Office of Science and Technology, EPA -822/R-02/034, 149 pp, April 2002

Approach for Addressing Dioxin in Soil at CERCLA and RCRA Sites
U.S. EPA, Office of Solid Waste and Emergency Response. OSWER Directive 9200.4-26, 6 pp, 1998.

Recommends preliminary remediation goals (PRGs) or starting points for setting cleanup levels for dioxin in soil at CERCLA and RCRA corrective action sites pending the release of EPA's comprehensive dioxin reassessment report and subsequent cross-program impact assessment.

Guidance on Non-NPL Removal Actions Involving Nationally Significant or Precedent-Setting Issues
OSWER Directive 9369.0-19.

Cleanup Levels for Dioxin at Superfund Sites

This EPA webpage includes links to Regional Screening Levels (RSLs) for dioxin.

Land Disposal Restrictions Summary, Volume I: Solvents and Dioxins
U.S. EPA, Office of Solid Waste. EPA 530-SW-87-019A, 54 pp, 1987.

Questions and Answers on Land Disposal Restrictions for Solvents and Dioxins
U.S. EPA, Office of Solid Waste. EPA 530-SW-87-020, 42 pp, 1987.