Risk Evaluation for 1,1-Dichloroethane
In June 2025, EPA released the final risk evaluation under the Toxic Substances Control Act (TSCA) for 1,1-dichloroethane. EPA designated 1,1-dichloroethane as a high priority chemical in December 2019.
Find information about other chemicals undergoing risk evaluations under TSCA.
On this page:
- Risk Evaluation Findings
- Background on 1,1-Dichloroethane
- Uses of 1,1-Dichloroethane
- Recent Activities and Opportunities for Public Comment
- Risk Evaluation and Supporting Documents
Risk Evaluation Findings
EPA determined that 1,1-dichloroethane presents an unreasonable risk of injury to human health driven by three conditions of use (COUs). The other five COUs that EPA examined do not significantly contribute to the unreasonable risk determination for 1,1-dichloroethane. EPA did not identify exposures to the general population, or to the environment, associated with COUs of 1,1-dichlorethane as significantly contributing to the unreasonable risk.
EPA considered all reasonably available information, including test order data substantiating the use of PPE, when determining which COUs significantly contribute to the unreasonable risk determination. For COUs that significantly contribute to the unreasonable risk determination based on identified risk to workers, these risk determinations do not reflect the use of PPE; however, as the risk evaluation shows, effective use of PPE will reduce exposures and mitigate risk in the absence of other exposure controls (e.g., engineering controls). Only worker exposure, and not exposure to the general population or the environment, significantly contributes to EPA’s finding of unreasonable risk.
Background on 1,1-Dichloroethane
1,1-dichloroethane (CASRN 75-34-3) is a colorless, oily liquid with a chloroform- or ether-like odor. The primary use of 1,1-dichloroethane is in organic chemical manufacturing. Information from the 2016 Chemical Data Reporting (CDR) for 1,1-dichloroethane indicates the reported production volume is between 100 million to one billion lbs/year.
Uses of 1,1-Dichloroethane
In the final scope, EPA identified conditions of use associated with the manufacturing; processing; distribution in commerce; commercial use; and disposal of 1,1-dichloroethane, for example:
- In organic chemical and other chemical product and preparation manufacturing; and
- As a laboratory chemical.
The above listed conditions of use are ways that a person or the environment could be potentially exposed to this chemical. However, when conducting a TSCA risk evaluation, EPA also considers the hazards (i.e., health effects or environmental impacts) that could occur from coming in contact with a chemical.
Recent Activities and Opportunities for Public Comment
In June 2025, EPA released the final risk evaluation for 1,1-dichloroethane. EPA will now begin the risk management process to address the unreasonable risk presented by 1,1-dichloroethane. EPA will release a proposed rule under TSCA section 6 to protect workers from the identified risks. The public will have an opportunity to comment on a proposed rule before the final requirements are put in place.
In July 2024, EPA released the draft risk evaluation for 1,1-dichloroethane for public comment and peer review. EPA accepted public comments on the draft risk evaluation for 60 days following publication in the Federal Register via docket EPA-HQ-OPPT-2024-0114 at www.regulations.gov.
EPA held a virtual public meeting of the Science Advisory Committee on Chemicals (SACC) to discuss the draft risk evaluation on September 17-20, 2024. EPA also held a virtual preparatory public meeting on August 27, 2024, for the SACC and the public to consider and ask questions regarding the scope and clarity of the draft charge questions. View the SACC website for more information on these meetings.
In August 2020, EPA published a final scope document outlining the hazards, exposures, conditions of use, and the potentially exposed or susceptible subpopulations the agency expects to consider in its risk evaluation. The agency released the draft scope in April 2020 and took public comments on the draft document.
- Read the final scope of the risk evaluation for this chemical and EPA’s response to comments on the draft scope.
- View the dockets for this chemical, EPA-HQ-OPPT-2018-0426 and EPA-HQ-OPPT-2024-0114 on www.regulations.gov.
Risk Evaluation and Supporting Documents
Read the Federal Register notice.
View the supporting documents in docket EPA-HQ-OPPT-2018-0426.
- Risk Evaluation for 1,1-Dichloroethane (pdf)
- Summary of and Response to External Peer Review and Public Comments on the Risk Evaluation for 1,1-Dichloroethane and Human Health Hazard Technical Support Document for 1,2-Dichloroethane (pdf)
- Nontechnical Summary of the TSCA Risk Evaluation for 1,1-Dichloroethane (pdf)
- Systematic Review Protocol for 1,1-Dichloroethane -- Systematic Review Support Document for the Risk Evaluation (pdf)
- Risk Evaluation for 1,1-Dichloroethane Systematic Review Supplemental File: Data Quality Evaluation and Data Extraction Information for Physical and Chemical Properties (pdf)
- Risk Evaluation for 1,1-Dichloroethane Systematic Review Supplemental File: Data Quality Evaluation and Data Extraction Information for Environmental Fate and Transport (pdf)
- Risk Evaluation for 1,1-Dichloroethane Systematic Review Supplemental File: Data Quality Evaluation and Data Extraction Information for Environmental Release and Occupational Exposure (pdf)
- Risk Evaluation for 1,1-Dichloroethane Systematic Review Supplemental File: Data Quality Evaluation and Data Extraction Information for Dermal Absorption (pdf)
- Risk Evaluation for 1,1-Dichloroethane Systematic Review Supplemental File: Data Quality Evaluation Information for General Population, Consumer, and Environmental Exposure (pdf)
- Risk Evaluation for 1,1-Dichloroethane Systematic Review Supplemental File: Data Extraction Information for General Population, Consumer, and Environmental Exposure (pdf)
- Risk Evaluation for 1,1-Dichloroethane Systematic Review Supplemental File: Data Quality Evaluation Information for Human Health Hazard Epidemiology (pdf)
- Risk Evaluation for 1,1-Dichloroethane Systematic Review Supplemental File: Data Quality Evaluation Information for Human Health Hazard Animal Toxicology (pdf)
- Risk Evaluation for 1,1-Dichloroethane Systematic Review Supplemental File: Data Quality Evaluation Information for Environmental Hazard (pdf)
- Risk Evaluation for 1,1-Dichloroethane Systematic Review Supplemental File: Data Extraction Information for Environmental Hazard and Human Health Hazard Animal Toxicology and Epidemiology (pdf)
- Risk Evaluation for 1,1-Dichloroethane Supplemental File: Supplemental Information on Environmental Release and Occupational Exposure Assessment (pdf)
- Risk Evaluation for 1,1-Dichloroethane - Supplemental Information File: Risk Calculator for Occupational Exposures (xlsx)
- Risk Evaluation for 1,1-Dichloroethane - Supplemental Information File: Laboratory Chemical Occupational Exposure and Environmental Release Modeling Results (xlsx)
- Risk Evaluation for 1,1-Dichloroethane - Supplemental Information File: Repackaging Environmental Release Modeling Results (xlsm)
- Risk Evaluation for 1,1-Dichloroethane - Supplemental Information File: Occupational Exposure Scenario Mapping Results (xlsx)
- Risk Evaluation for 1,1-Dichloroethane - Supplemental Information File: Supplemental Information on AERMOD TRI Exposure and Risk Analysis (xlsx)
- Risk Evaluation for 1,1-Dichloroethane - Supplemental Information File: Air Exposures and Risk Estimates for 1,1-Dichloroethane Generic Releases to Ambient AERMOD Analysis (xlsx)
- Risk Evaluation for 1,1-Dichloroethane - Supplemental Information File: Supplemental Information on AERMOD NEI Exposure and Risk Analysis (xlsx)
- Draft Risk Evaluation for 1,1-Dichloroethane - Supplemental Information File: Ambient Monitoring Technology Information Center (AMTIC) 1,1-Dichloroethane Monitoring Data 2015 to 2020 (xlsx)
- Risk Evaluation for 1,1-Dichloroethane - Supplemental Information File: Supplemental Information on IIOAC TRI Exposure and Risk Analysis (xlsx)
- Risk Evaluation for 1,1-Dichloroethane - Supplemental Information File: AERMOD Input Specifications (xlsx)
- Risk Evaluation for 1,1-Dichloroethane - Supplemental Information File: Surface Water Concentration and Fish Ingestion and Swimming Central Tendency Exposure Estimates (xlsx)
- Risk Evaluation for 1,1-Dichloroethane - Supplemental Information File: Surface Water Concentration and Fish Ingestion and Swimming High-End Exposure Estimates (xlsx)
- Risk Evaluation for 1,1-Dichloroethane - Supplemental Information File: Drinking Water Exposure Estimates (xlsx)
- Risk Evaluation for 1,1-Dichloroethane - Supplemental Information File: TRV Calculator (xlsm)
- Risk Evaluation for 1,1-Dichloroethane Supplemental Information File: Benchmark Dose Modeling Results for 1,1-Dichloroethane (pdf)
- Risk Evaluation for 1,1-Dichloroethane Supplemental Information File: Supplemental Information on EPI Suite Modeling Results in the Fate Assessment (pdf)
- 1,1-Dichloroethane Dermal Absorption Study Analysis (pdf)
- Risk Evaluation for 1,1-Dichloroethane - Supplemental Information File: in vitro Dermal Absorption Study Calculation Sheet (xlsx)
- Risk Evaluation for 1,1-Dichloroethane - Supplemental Information File: Human Health Hazard Exposure Response (xlsx)
- Risk Evaluation for 1,1-Dichloroethane - Supplemental Information File: Water Quality Portal Data 2015 to 2020 (xlsx)
- Risk Evaluation for 1,1-Dichloroethane - Supplemental Information File: Estimates of Number of Workers and ONUs (xlsx)
- Risk Evaluation for 1,1-Dichloroethane - Supplemental Information File: Repackaging Occupational Exposure Modeling Results (xlsm)
- Risk Evaluation for 1,1-Dichloroethane Supplemental File Folder: Supplemental Information on the AERMOD Input Files and Modeling Results (Generic Release Scenarios) (pdf)
- Risk Evaluation for 1,1-Dichloroethane Supplemental File Folder: Supplemental Information on the AERMOD Input Files and Modeling Results (NEI) (pdf)
- Risk Evaluation for 1,1-Dichloroethane Supplemental File Folder: Supplemental Information on the AERMOD Input Files and Modeling Results (TRI) (pdf)