EPA Work Plan chemicals and TSCA priority lists explained
EPA Work Plan chemicals are the 90 substances on the 2014 assessment list, not a ban. High- and low-priority TSCA designations do not mean the same thing.
EPA Work Plan chemicals are substances EPA identified for further assessment in its historical TSCA Work Plan. The October 2014 update contains 90 chemicals, and inclusion is not a ban, a formal high-priority designation or a finding of unreasonable risk.
For a manufacturer, importer or product-stewardship team, the first job is to name the stage the substance is actually in. Work Plan membership, a priority designation, a risk evaluation and a risk-management rule are different records. EPA separates those steps in its prioritization of existing chemicals.
Where to find the EPA Work Plan chemicals list
Use EPA's 2014 Work Plan update for the historical list. An entry means EPA intended to consider the substance for assessment. It does not mean EPA had already found unreasonable risk. Match the name and the CAS Registry Number before you copy an entry into a compliance file.
EPA released the original Work Plan in March 2012 to focus its Existing Chemicals Program. Screening looked at hazard, exposure, persistence and bioaccumulation. Factors included children's health concerns, neurotoxicity, persistent, bioaccumulative and toxic characteristics, probable or known carcinogenicity, use in children's products, and detection in biomonitoring. The 2014 update used 2012 Chemical Data Reporting submissions and 2011 Toxics Release Inventory reporting to revise exposure rankings. EPA can also assess a substance that never sat on the Work Plan. Those points are on the Work Plan page.
That page was last updated on March 19, 2026. It still warns that some content may be out of date until the pages conform to the June 22, 2016 TSCA amendments. A footer date does not convert the old selection method into today's prioritization process. Keep the historical list and the current process page as separate references.
Why the 2014 list still matters
At least 50% of the substances undergoing EPA risk evaluations must, at any given time, come from the 2014 Work Plan. That floor applies to the evaluation program. It does not require half of every proposed priority batch to come from the list. EPA states the requirement in its prioritization guidance, and the same floor is in TSCA section 6.
When EPA selects high-priority substances, it must prefer Work Plan chemicals with a persistence and bioaccumulation score of three, and Work Plan chemicals that are known human carcinogens and have high acute and chronic toxicity. The carcinogen condition and the toxicity condition apply together. TSCA section 6 keeps that conjunction.
Work Plan membership can affect a later selection. It doesn't tell you whether a given use is restricted today.
High priority versus low priority under TSCA
High-priority status means EPA must begin a risk evaluation. Without considering costs or other nonrisk factors, EPA has concluded that the substance may present an unreasonable risk of injury to health or the environment because of a potential hazard and a potential route of exposure under its conditions of use, including an unreasonable risk to potentially exposed or susceptible subpopulations the Administrator identifies as relevant. The designation is a screening decision. EPA says it is not an indication of risk, and it is not a finding that unreasonable risk exists. The test is in EPA's designation standards.
Low-priority status means sufficient information shows the substance does not meet that high-priority standard. Costs and other nonrisk factors stay out of this decision too. Risk evaluation is not warranted at that time. EPA can revise the designation if new information supports a change. Low priority is not an approval of every use, and EPA says it is not an indication of safety, under the same process.
| Record or decision | What it means | What it does not establish |
|---|---|---|
| Historical Work Plan entry | EPA intended to consider the chemical for assessment | A ban, a risk finding or a formal high-priority designation |
| Final high-priority designation | Risk evaluation begins | An indication of risk, or a finding of unreasonable risk |
| Final low-priority designation | Evaluation is not warranted at designation | A safety finding or approval of every use |
| Unreasonable-risk determination | A separate basis for risk-management action | The exact controls in a final rule |
EPA's guidance defines conditions of use as the circumstances, determined by EPA, in which a substance is intended, known or reasonably foreseen to be manufactured, processed, distributed, used or disposed of. TSCA section 6 is the hook for a later risk-management rule. That rule is a different decision from designation.
The December 2019 high-priority cohort
EPA finalized 20 high-priority designations on December 20, 2019. The names below follow EPA's final scope documents:
- 1,3-Butadiene; p-dichlorobenzene; 1,1-dichloroethane; 1,2-dichloroethane; trans-1,2-dichloroethylene.
- 1,2-Dichloropropane; ethylene dibromide; HHCB; tetrabromobisphenol A (TBBPA); triphenyl phosphate (TPP).
- 1,1,2-Trichloroethane; tris(2-chloroethyl) phosphate (TCEP); diethylhexyl phthalate (DEHP); dicyclohexyl phthalate (DCHP); diisobutyl phthalate (DIBP).
- Butyl benzyl phthalate (BBP); dibutyl phthalate (DBP); phthalic anhydride; o-dichlorobenzene; formaldehyde.
These are historical designations. They do not mean all 20 chemicals are still awaiting evaluation. DIDP, DINP and D4 appear in the wider evaluation program, but they are not members of this 2019 cohort. EPA's evaluation tracker already shows completed evaluations for several of the 20. Read the chemical-specific entry before you assign a present status.
Five high-priority designations in December 2024
EPA finalized high-priority designations for five more substances on December 18, 2024. All five were selected from the 2014 Work Plan, according to its prioritization actions tracker.
| Chemical | CAS Registry Number |
|---|---|
| Acetaldehyde | 75-07-0 |
| Acrylonitrile | 107-13-1 |
| Benzenamine (aniline) | 62-53-3 |
| Vinyl chloride | 75-01-4 |
| 4,4′-Methylene bis(2-chloroaniline) (MBOCA) | 101-14-4 |
Benzenamine is aniline, CAS 62-53-3, not benzene. A shared root is a bad reason to merge the two files.
Formaldehyde and acetaldehyde belong to different cohorts: formaldehyde in 2019, acetaldehyde in 2024. Similar names do not make their hazards or controls interchangeable. Use the substance-specific records linked from EPA's prioritization tracker.
When were the low-priority designations finalized?
EPA initiated prioritization for 40 substances on March 20, 2019, 20 intended as high priority and 20 intended as low priority. It finalized the 20 low-priority designations on February 20, 2020. The 2019 date is the start, not the final designation. Both dates are in EPA's prioritization actions.
Examples include D-gluconic acid, 1-octadecanol and 1,2-hexanediol. The full set, with identifiers, is on EPA's low-priority list. Low priority means no evaluation was warranted at designation. It is not an exemption from every other chemical rule.
What suppliers should check next
Start with the CAS number, especially where names look alike. Formaldehyde is CAS 50-00-0 in EPA's 2019 cohort documents. Acetaldehyde is CAS 75-07-0 in the December 2024 action. Write the source and the action date next to the identity.
A webpage update date is not the designation date.
The cohorts above are not a live status register. For a decision you will rely on, open the chemical's entry in EPA's evaluation tracker and read the linked documents.
In the substance register, keep a separate field for Work Plan inclusion, prioritization initiation, proposed designation, final designation, evaluation and any applicable risk-management rule. That stops an early selection step from being filed as a legal restriction. The stage split follows EPA's prioritization process.
Prioritization normally takes nine to twelve months. There is an initial 90-day information period, then a separate 90-day comment period on the proposed designation. Check the docket deadline before you send use or exposure information. The windows are described in EPA's process guidance.
After evaluation begins, TSCA gives EPA six months to publish the scope. The evaluation deadline is three years, with an extension of up to six months. Those are statutory deadlines. They are not evidence that a particular evaluation finished on time.
But a UK supplier selling into the US still has to keep this check separate from UK REACH. Don't infer a reporting duty or a mandatory SDS change from a priority label. Other EPA chemical regulations can still apply.
RegAffairs AI's answer on EPA Work Plan chemicals explains the list and the priority designations. Under TSCA section 6, risk-management measures can include restrictions, prohibitions, warnings and recordkeeping. A high-priority designation alone does not impose those controls.