Risk Evaluation for p-Dichlorobenzene

In August 2026, EPA released the draft risk evaluation and associated technical support documents for p-dichlorobenzene under the Toxic Substances Control Act (TSCA) for public comment. 

EPA will accept public comments on the draft risk evaluation for 60 days in the p-dichlorobenzene TSCA docket (EPA-HQ-OPPT-2018-0446) at www.regulations.gov.

EPA designated o-dichlorobenzene as a high priority chemical in December 2019 and the chemical is currently undergoing risk evaluation.

Find other information about other chemicals undergoing risk evaluations under TSCA. 

On this page:

• What is p-Dichlorobenzene?
• Draft Risk Evaluation for p-Dichlorobenzene
• Draft Risk Evaluation and Supporting Documents

What is p-Dichlorobenzene?

p-Dichlorobenzene (CASRN 106-46-7) is a colorless to white crystalline solid. It has a strong pungent odor. The primary uses for p-dichlorobenzene are in the manufacturing of plastic material and other chemicals manufacturing and as an odor agent in several products. Information from the 2016 Chemical Data Reporting (CDR) for p-dichlorobenzene indicates the reported production volume is between 50 million and 100 million lbs/year.

Draft Risk Evaluation for p-Dichlorobenzene?

EPA is preliminarily determining that p-dichlorobenzene presents an unreasonable risk of injury to human health driven by 7 evaluated worker conditions of use (COUs) and one consumer COU. These preliminary risk findings are driven by risks to workers from 7 COUs, risks to occupational non-users (ONUs) from 5 of those COUs, and risks to consumers associated with the air care products COU. EPA did not preliminarily identify any significant contribution to unreasonable risk for the general population, including fenceline communities, or the environment from the evaluated TSCA conditions of use. For COUs with unreasonable risk to workers, these preliminary risk determinations do not reflect the use of personal protective equipment (PPE); however, as the draft risk evaluation shows, appropriate engineering controls and PPE can reduce exposures and mitigate risk.

The draft risk evaluation found that workers, ONUs, and consumers may be exposed to p-dichlorobenzene through inhalation and dermal contact during manufacturing, processing, commercial uses, and consumer use of air care products. Because p-dichlorobenzene readily sublimates at room temperature, inhalation exposure is a key pathway considered in the assessment. EPA identified respiratory toxicity, liver toxicity, developmental toxicity, and neurotoxicity as the primary non-cancer hazards associated with exposure. EPA preliminarily determined that chronic inhalation exposure from air care products significantly contributes to unreasonable risk for consumers. EPA also preliminarily determined that general population pathways, including ambient air, indoor air, drinking water, and fenceline community exposures, as well as environmental exposures to aquatic and terrestrial organisms, do not significantly contribute to unreasonable risk. Additionally, EPA determined that p-dichlorobenzene is not likely to be carcinogenic to humans. EPA has moderate to robust confidence in the worker risk estimates and robust confidence in the consumer, general population, and environmental assessments. EPA is seeking public comment and additional information on occupational exposures, consumer use patterns, exposure controls, and other data that may inform the final risk evaluation. These preliminary conclusions apply only to the TSCA conditions of use evaluated in this draft risk evaluation; uses excluded under TSCA section 3(2)(B) were not assessed.

EPA will move quickly, after public comment, to finalize the risk evaluation. Should EPA continue to find unreasonable risk, EPA will then propose risk management actions under TSCA to reduce or eliminate unsafe workplace exposures.

EPA emphasizes that this evaluation is draft and does not represent a final Agency determination regarding the risks posed by this chemical. The findings and conclusions may change based on feedback received during the public comment period. Additionally, the release of a draft evaluation does not alter or impact any existing protections, regulations, or risk management measures currently in place for this chemical. All current safeguards remain in place.

Draft Risk Evaluation and Supporting Documents

View the Federal Register Notice and supporting documents in TSCA docket EPA-HQ-OPPT-2018-0446. 

• Draft Risk Evaluation for p-Dichlorobenzene (pdf) (4.19 MB)
• Draft Chemistry, Fate, Release, and Exposure Assessment for p-Dichlorobenzene (pdf) (6.2 MB)
• Draft Human Health and Environmental Hazard Assessment for p-Dichlorobenzene (pdf) (4.18 MB)
• Draft Data Quality Evaluation Information for Human Health Hazard Epidemiology for p-Dichlorobenzene (pdf) (361.88 KB)
• Draft Data Quality Evaluation Information for Human Health Hazard Animal Toxicology for p-Dichlorobenzene (pdf) (1.87 MB)
• Draft Data Quality Evaluation Information for Environmental Hazard for p-Dichlorobenzene (pdf) (5.02 MB)
• Draft Data Extraction Information for Environmental Hazard and Human Health Hazard Animal Toxicology and Epidemiology for p-Dichlorobenzene (pdf) (1.34 MB)
• Draft Data Quality Evaluation and Data Extraction Information for Physical and Chemical Properties for p-Dichlorobenzene (pdf) (1.75 MB)
• Draft Data Quality Evaluation and Data Extraction Information for Environmental Fate and Transport for p-Dichlorobenzene (pdf) (1.47 MB)
• Draft Data Quality Evaluation and Data Extraction Information for Environmental Release and Occupational Exposure for p-Dichlorobenzene (pdf) (1.18 MB)
• Draft Data Quality Evaluation Information for General Population, Consumer, and Environmental Exposure for p-Dichlorobenzene (pdf) (1.47 MB)
• Draft Data Extraction Information for General Population, Consumer, and Environmental Exposure for p-Dichlorobenzene (pdf) (2.26 MB)
• Draft Benchmark Dose Modeling Results for p-Dichlorobenzene (pdf) (3.79 MB)
• Draft Data Quality Evaluation Information for Dermal Absorption for p-Dichlorobenzene (pdf) (235.6 KB)
• Draft Transcriptomic Assessment for o-Dichlorobenzene and p-Dichlorobenzene (pdf) (4.46 MB)

Additional technical support files for the draft risk evaluation of p-dichlorobenzene (zip)