A regulatory deadline for perchloroethylene arrives today, but the larger facilities' decision may be what comes after it. Under EPA's 2024 Toxic Substances Control Act rule, processors generally may no longer process perchloroethylene, or PCE, beginning September 9 except for uses specifically allowed to continue under a Workplace Chemical Protection Program or other workplace controls. The prohibition is part of a staggered phaseout covering manufacturing, processing, distribution, and many industrial and commercial uses.
For facilities that will continue using PCE under the rule, EPA has extended several workplace compliance dates. Initial exposure monitoring is now due by June 21, 2027. Facilities must meet the existing chemical exposure limit, establish regulated areas, provide required respiratory protection, and implement workplace information and training requirements by September 20, 2027, with exposure control plans required by December 20, 2027. Carbon tetrachloride follows a similar workplace schedule, with initial monitoring also due by June 2027 and the exposure limit and related controls required by September 2027.
The additional time is useful. It also changes the question companies should be asking. Compliance is no longer only about determining whether exposure exists. For some operations, the next step may be deciding whether ventilation, process enclosure, equipment changes, or chemical substitution belongs in the capital plan.
Exposure Data Can Trigger an Engineering Decision
EPA's existing chemical exposure limit, or ECEL, establishes the maximum average airborne concentration allowed under the applicable workplace protection program. For PCE, the final ECEL is 0.14 parts per million over an eight-hour time-weighted average. Carbon tetrachloride's limit is considerably lower at 0.03 ppm. Monitoring tells a facility where it stands against those limits. If existing controls keep exposures below the required level, compliance may center on continued monitoring, documentation, training, and maintaining current safeguards. If they do not, the problem becomes more operational.
NIOSH's hierarchy of controls places elimination and substitution above engineering controls, followed by administrative controls and personal protective equipment. Controls that remove the hazard or isolate workers from it generally depend less on individual behavior than respirators, work practices, or other administrative measures. An exposure reading can ultimately lead to a question for facilities and engineering teams. Can the hazard be designed out of the process, a version of the same use-by-use analysis the EPA has applied to other chemical exposure findings under TSCA?
Ventilation Is More Than an EHS Expense
One of the clearest examples is local exhaust ventilation. NIOSH identifies ventilation, equipment modification, barriers, and other physical changes as engineering controls that can reduce exposure before a contaminant reaches a worker. The agency notes that these systems can carry higher upfront costs than administrative controls or PPE, but operating costs may be lower over time because they require less worker intervention.
PCE provides a practical illustration. NIOSH guidance for dry-cleaning operations recommends capturing solvent vapor at or near the point where it is released rather than relying only on general room ventilation. Local exhaust ventilation can reduce the concentration reaching a worker's breathing zone and limit the spread of vapor through the facility. The same engineering principle extends well beyond dry cleaning. PCE is also used as a chemical intermediate, processing aid, and solvent in industrial operations, while carbon tetrachloride is used as a feedstock in manufacturing refrigerants and other chemicals.
Depending on the process, reducing exposure could involve isolating equipment, modifying transfer systems, improving capture ventilation, automating tasks, or substituting another chemical. Those are not always quick projects. Ventilation changes can require airflow studies, ductwork, make-up air, electrical modifications, and commissioning. Process changes may require engineering review, product testing, or customer qualification. Substitution can introduce an entirely different set of technical and procurement questions. The compliance calendar may therefore understate the amount of lead time some facilities need.
PPE Solves the Immediate Problem, Not the Whole Problem
Respirators and other personal protective equipment remain part of EPA's workplace requirements where needed. But PPE sits at the bottom of the NIOSH hierarchy because its effectiveness depends heavily on correct selection, fit, training, maintenance, and consistent worker use. Engineering controls generally operate more independently once properly designed and maintained.
This creates an economic question as well as a safety question. A facility can compare the cost of a physical improvement against the recurring expense of respirator programs, monitoring, training, restricted work areas, and administrative controls. The lowest-cost compliance measure in the first year may not necessarily be the lowest-cost solution over the life of the operation. For facilities that expect continued chemical use, engineering controls may also provide benefits beyond regulatory compliance, reducing routine worker exposure, simplifying operating procedures, or improving indoor air management, an operational calculus that has already shaped how EPA and OSHA coordinate on workplace chemical rulemaking more broadly.
The Extension Creates a Capital-Planning Window
EPA finalized the deadline extensions this summer while it continues reconsidering aspects of both chemical rules. The agency has said the underlying unreasonable-risk findings remain in place, even as it evaluates implementation issues and potential revisions, a distinction that has come up in other recent TSCA reviews where EPA has sought additional industry data before finalizing risk management rules. Companies should continue planning against the requirements currently in force rather than assuming reconsideration will eliminate the need for controls.
The most useful first step is not necessarily ordering equipment. It is connecting EHS data to facility planning early enough to determine whether equipment will be necessary at all. Companies that map PCE and carbon tetrachloride uses, evaluate existing monitoring data, and identify potential control gaps now have time to separate simple compliance actions from projects that need engineering, procurement, and capital approval.
That is the larger shift behind the new chemical rules. Monitoring tells a company whether it has an exposure problem. Engineering determines whether that problem becomes a recurring operating burden or something the facility can control at the source.
