On August 10, 2026, the U.S. Environmental Protection Agency (EPA) published draft risk assessments for o-dichlorobenzene (o-DCB) and p-dichlorobenzene (p-DCB) under the Toxic Substances Control Act (TSCA) in the Federal Register, opening a 60-day public comment period.
Substance Details
|
Substance |
CAS No. |
Primary Uses |
|
o-Dichlorobenzene (o-DCB) |
95-50-1 |
Dye/pigment solvent, lubricant, degreaser, inks, air fresheners, ceramic glazes, etc. |
|
p-Dichlorobenzene (p-DCB) |
106-46-7 |
Thermoplastic manufacturing, solvent, air fresheners (continuous-release), lubricating greases, building materials, etc. |
Key Findings
EPA preliminarily determined that both substances present unreasonable risks to human health under specific conditions of use. The primary drivers include:
- Exposure pathways: Inhalation of vapors (primary route) and dermal contact (liquid splashes or solid contact)
- Key risk scenarios: Exposure during industrial/commercial manufacturing, processing, use, and consumer use
Public Comment
EPA is specifically seeking actual use data for both substances, including: details on manufacturing processes and worker activities; on-site monitoring concentrations; actual use of personal protective equipment (PPE) and engineering controls; composition and availability of consumer products (e.g., septic tank cleaners, air fresheners); and feedback on the applicability of specific exposure models (e.g., automotive refinish spray model, indoor environmental concentration model IECCU).
Comments are due by October 9, 2026, and must be submitted via regulations.gov under Docket Nos. EPA–HQ–OPPT–2018–0444 (o-dichlorobenzene) and EPA–HQ–OPPT–2018–0446 (p-dichlorobenzene).
Further information
