Worker Chemical Safety | Regulatory Insight

EPA and OSHA are increasingly addressing the same workplace chemical exposures through separate federal regulatory frameworks. On July 22, 2026, the American Chemistry Council (ACC) announced that a coalition of 75 organizations had asked the U.S. Environmental Protection Agency (EPA), the Occupational Safety and Health Administration (OSHA), and the Office of Management and Budget to establish a single, consistent federal framework for worker chemical safety. The coalition urged the different agencies to use Section 9 of the Toxic Substances Control Act (TSCA) to reduce duplicative or conflicting requirements and clarify their respective roles.

Overlapping Authority Can Produce Conflicting Signals

OSHA has long been the primary federal agency responsible for workplace safety and health. It develops occupational standards, conducts inspections, enforces employer obligations, and oversees State occupational safety and health plans. Under the amended Toxic Substances Control Act (TSCA), however, EPA must evaluate chemicals across their conditions of use, including occupational exposures, and regulate unreasonable risks identified during that process.

That structure creates an area of genuine overlap. Overlap itself does not necessarily create a problem. Separate agencies may appropriately examine the same chemical exposure through different statutory lenses. The challenge arises when parallel evaluations rely on different data, assumptions, terminology, or control expectations without a clear process for reconciling those differences.

A chemical used at one facility may be subject to an OSHA permissible exposure limit or other workplace requirements while also becoming subject to an EPA risk-management rule with its own exposure limits, monitoring provisions, personal protective equipment requirements, recordkeeping duties, or compliance schedules. When these parallel processes are not coordinated, differences in exposure assumptions, risk benchmarks, monitoring approaches, or control requirements can ultimately translate into duplicative, or potentially conflicting, workplace obligations.

Congress recognized the potential for overlapping federal authority to create unnecessary duplication, and TSCA Section 9 provides a mechanism for addressing that risk. EPA’s description of TSCA Section 9 explains that the agency should consult and coordinate with other federal agencies to maximize enforcement while imposing the least burden from duplicative requirements. EPA and OSHA also signed a memorandum of understanding in January 2025 addressing coordination and information exchange for chemicals subject to EPA’s risk evaluation and risk-management authorities under TSCA Section 6. The memorandum recognizes that the agencies’ control measures may overlap and calls for information sharing, consultation, coordinated communications, and cooperation during inspections and enforcement.

While the memorandum is an important foundation, the coalition’s request goes further. It calls for a durable operating framework that clearly assigns responsibilities and prevents regulated workplaces from facing two competing federal playbooks for the same exposure.

Coordination should therefore focus not merely on whether two agencies are addressing the same chemical, but on where parallel activity is complementary, where it is unnecessarily duplicative, and where differences could create conflicting expectations for employers and workers. EPA’s August 6, 2026, draft TSCA risk evaluations for ortho-dichlorobenzene (oDCB) and para-dichlorobenzene (pDCB) provide a timely example.

The Dichlorobenzene Draft Evaluations Show Why Coordination Is Urgent

Both ortho-dichlorobenzene (oDCB) and para-dichlorobenzene (pDCB) are found in household and commercial products and can evaporate into indoor air. EPA preliminarily found that:

• oDCB contributes to unreasonable risk to workers under 14 conditions of use through both inhalation and dermal exposure;
• pDCB contributes to unreasonable risk to workers under seven conditions of use through inhalation and dermal exposure; and
• both chemicals may present non-cancer hazards involving developmental, liver, and respiratory toxicity.

The evaluations are drafts, not final determinations or new workplace rules. Existing protections remain in place during EPA’s review, and the agency has opened a 60-day public-comment period. EPA is working toward a February 12, 2027, deadline for final evaluations.

The drafts nevertheless illustrate the point at which interagency coordination becomes consequential. EPA’s worker risk estimates do not assume that personal protective equipment is being used as the basis for the risk determination, although the agency separately discusses how PPE and other controls may reduce exposure. Employers, by contrast, manage workplace risks through established industrial hygiene programs that may incorporate engineering controls, work practices, respiratory protection, dermal protection, training, medical surveillance, and exposure monitoring.

If EPA retains its “unreasonable risk” findings in the final evaluations, TSCA requires the agency to propose risk-management measures. At that stage, differences in exposure assumptions, risk benchmarks, or treatment of existing controls can translate into different compliance expectations. Those differences are not necessarily inappropriate, but without coordination, employers may be left to determine whether the requirements are complementary, duplicative, or conflicting. Without early alignment, an employer could be asked to reconcile two agencies’ approaches to the same worker, chemical, task, and control system.

A shared understanding of workplace conditions should extend beyond generic exposure scenarios. It should incorporate how chemicals are actually handled in the workplace, the frequency and duration of tasks, engineering controls, work practices, respiratory and dermal protection, exposure variability across job functions, and available monitoring data. Where regulatory models rely on conservative or standardized assumptions, empirical workplace data can help determine whether those assumptions appropriately characterize actual worker exposure.

The dichlorobenzene evaluations therefore present a practical coordination test. EPA and OSHA should work from a shared understanding of real-world workplace conditions, including available exposure measurements, task-specific activities, engineering controls, work practices, and PPE, while clearly explaining how those conditions are incorporated into regulatory decisions. This data can also help identify where variability among tasks, facilities, or worker groups may not be fully captured by generalized regulatory scenarios.

What an Effective Federal Framework Should Accomplish

A coordinated federal framework does not require either agency to abandon its statutory responsibilities. EPA and OSHA differ in scope, authority, and the populations within their respective jurisdictions. A coordinated framework should promote consistency without requiring uniformity. EPA and OSHA operate under different statutory authorities, and those differences may appropriately lead to different analytical approaches or regulatory decisions. The goal should not be to achieve identical outcomes in every case, but rather to ensure that differences are deliberate, scientifically supported, transparent, and compatible in practice. Effective coordination should respect those distinctions while making the combined system understandable and workable.

At a minimum, a coordinated approach should:

1. Use a common factual record. EPA and OSHA should begin from a common factual record where appropriate, sharing occupational exposure data, control information, incident experience, and industry practices before key assumptions become embedded in separate agency actions.
2. Clarify responsibility and minimize unnecessary duplication. Stakeholders should know which agency is leading each regulatory function, where complementary review adds value, how the other agency’s standards were considered, and which agency will oversee implementation and enforcement.
3. Reconcile technical differences. Where both agencies address the same risk, differences in definitions, exposure metrics, sampling methods, control hierarchies, PPE provisions, recordkeeping, or compliance dates should be identified early and either aligned or clearly explained.
4. Communicate through one practical implementation pathway. Workers and employers should not have to infer how one agency’s requirements interact with the other’s. Joint guidance should explain the combined obligations in plain language.
5. Account for OSHA-approved State Plans. Coordination at the federal level should anticipate how requirements will interact with state occupational safety and health programs and EPA’s regional and state partners.

Done well, coordination can improve protection by directing resources toward exposure reduction instead of resolving administrative contradictions. Consistency also makes requirements easier to train, audit, enforce, and sustain across multiple facilities.

IRIS Closure Highlights the Importance of Coordinated Chemical Assessment

The EPA-OSHA discussion is also part of a broader federal question: when does consolidation or de-duplication improve chemical assessment, and what coordination is necessary to preserve scientific rigor when responsibilities are redistributed? As discussed in RHP’s recent article, “U.S. Environmental Protection Agency Closes Down Integrated Risk Information System,” EPA’s decision to close the IRIS program may shift greater responsibility for chemical risk evaluations to individual program offices.

IRIS historically provided a centralized source of hazard assessments and toxicity values used across EPA programs, states, and other organizations. Its closure did not cause the ACC coalition’s request, but both developments expose the same governance challenge: when scientific and regulatory decisions are distributed among separate programs or agencies, deliberate coordination becomes more important.

Avoiding duplication of efforts can improve regulatory efficiency when it reduces redundant analysis, clarifies responsibility, and allows scientific resources to be focused where they add the most value. But streamlining should reduce redundant process, not eliminate necessary scientific scrutiny. As assessment responsibilities shift among EPA programs, maintaining transparent methods, appropriate peer review, shared data, and clear documentation of key assumptions will remain important. The same principle applies to EPA-OSHA coordination. The objective should not simply be to remove one agency from the process, but to determine where each agency adds value, establish clear responsibility, and prevent parallel processes from producing unnecessary duplication or incompatible workplace requirements.

As assessment responsibilities become more distributed, organizations may encounter different toxicity values, exposure assumptions, or risk thresholds developed for different statutory purposes. Whether that produces greater consistency or greater fragmentation will depend on how those programs coordinate their scientific methods, data, and assumptions. Scientific consistency does not require analytical uniformity. Different programs may appropriately reach different conclusions because of their statutory mandates, populations of interest, or decision contexts. However, where methods, assumptions, or values differ, those differences should be transparent, scientifically justified, and understood before they translate into potentially conflicting requirements.

How RHP’s Human Health Risk Sciences Practice Can Help

RHP Risk Management’s Human Health Risk Sciences (HHRS) practice helps organizations evaluate chemical risks and respond to changing regulatory expectations with defensible science. HHRS integrates exposure science, toxicology, epidemiology, and risk assessment to evaluate hazards, quantify exposures, and characterize potential risk in occupational, environmental, and consumer settings.

RHP’s multidisciplinary teams support clients through:

• systematic review, hazard identification, and weight-of-evidence evaluation;
• dose-response analysis, benchmark dose modeling, and physiologically based pharmacokinetic modeling;
• environmental and occupational sampling, laboratory testing, exposure modeling, and exposure reconstruction;
• risk characterization and communication; and
• scientific support for regulatory strategy, product stewardship, litigation, and public-health decision-making.

For chemicals undergoing TSCA review, these capabilities can help organizations test regulatory assumptions against measured and observed workplace conditions and identify where additional exposure or control-effectiveness data may be needed to support regulatory decision-making. This may include evaluating task-specific exposure data, the effectiveness of engineering and administrative controls, actual PPE use and performance, variability across workers or facilities, and the representativeness of modeled exposure scenarios. Connecting HHRS expertise with industrial hygiene information from the field can also help translate regulatory risk evaluations into practical worker-protection decisions.

Preparing for the Next Phase of Chemical Regulation

Companies that manufacture, process, formulate, distribute, or use chemicals under TSCA should not wait for final risk-management rules to examine potential conflicts. They should begin by mapping affected conditions of use, inventorying existing OSHA and industrial hygiene controls, evaluating the quality of available exposure data, and identifying where EPA’s assumptions differ from workplace reality.

Effective federal coordination should be judged not by whether every agency uses identical approaches, but by whether responsibilities are clear, scientific differences are transparent and justified, workplace conditions are realistically characterized, and regulatory requirements can be implemented together in a coherent worker-protection program. The draft dichlorobenzene evaluations show that the need is no longer theoretical. As EPA’s chemical-assessment structure evolves following the closure of IRIS, a coordinated federal approach will be essential to reduce regulatory uncertainty without compromising health.

Contact RHP Risk Management to discuss how integrated exposure science, toxicology, epidemiology, risk assessment, and industrial hygiene support can help your organization prepare for emerging TSCA and workplace chemical-safety requirements, or call (866) 481-8188 to schedule a consultation.

This article is provided for informational purposes and does not constitute legal advice. The oDCB and pDCB risk evaluations discussed above are drafts and remain subject to public comment and revision.