On June 5, 2026, the U.S. Environmental Protection Agency proposed significant new use rules (SNURs) for 35 chemical substances under the Toxic Substances Control Act. One of those substances, multi-walled carbon nanotubes, has since been finalized on a split-out basis and takes effect on September 22, 2026. For manufacturers, importers, and processors, TSCA SNUR compliance now runs on two clocks: one substance is enforceable within weeks, while 34 remain in proposed status. This guide explains what changed, who is affected, and where obligations attach across the TSCA framework.

Book a compliance review to check these 35 substances against your active supplier and material lists before any of the remaining rules are finalized.

Key Takeaways

📌 EPA proposed SNURs for 35 chemical substances (the 25-3.5e batch) on June 5, 2026; one substance, multi-walled carbon nanotubes (P-22-163), is now final.

⏳ P-22-163 becomes effective September 22, 2026, triggering TSCA Section 13 import certification ahead of the other 34 substances.

⚠️ Export notification under TSCA Section 12(b) is already active for the full batch as of July 6, 2026, even though 34 substances remain proposed.

🏭 Batteries, semiconductors, display materials, coatings, paving additives, and consumer products are the most exposed sectors.

📄 Most substances in this batch carry no article or matrix exemption, so downstream incorporation does not automatically remove obligations.

🤖 Screening supplier data against 35 PMN substances at scale is where CORA-powered regulatory intelligence reduces manual review time.

What Is a TSCA SNUR and Why This Batch Matters

A significant new use rule is a notification requirement issued under TSCA Section 5(a)(2). When EPA determines that a use of a chemical substance would be a "significant new use," any person intending to manufacture, import, or process that substance for that use must notify EPA before commencing.

In this batch, the substances were the subject of premanufacture notices and are already subject to TSCA Section 5(e) consent orders. For nearly every entry, the proposed significant new use is simply the absence of the underlying order's protective measures: personal protective equipment, respirators, hazard communication, and use, release, or disposal limits. The rule extends those protections from the original submitter to all future manufacturers and processors. This is core chemical and hazmat compliance territory for regulated manufacturers.

Inside the 25-3.5e Batch: 35 Substances, One Finalized

The proposed rule covers 35 substances across 36 PMN case numbers. One CFR section (§721.12230) covers two PMNs, P-22-187 and P-24-88, for the same mixed metal oxide. The batch is now split into two compliance timelines.

The Substance That Is Already Final: Multi-Walled Carbon Nanotubes (P-22-163)

On July 24, 2026, EPA published a standalone final rule for P-22-163 (§721.12229), a battery-manufacture additive imported into the United States. One commenter, Cnano Technology USA, Inc., requested expedited finalization, and EPA granted it rather than waiting for the full batch. The rule is effective September 22, 2026. Once effective, both export notification and import certification apply to this substance specifically. Track this through BOM-level compliance intelligence so the affected products are flagged before the effective date.

The 34 Substances Still in Proposed Status

The other 34 substances remain proposed, with no final action yet. A critical screening detail: there are two separate "multi-walled carbon nanotubes" entries. P-22-163 (§721.12229) is final, while P-23-105 (§721.12233) is a distinct substance and remains proposed with a different timeline. Do not conflate them when reviewing supplier declarations. Consolidating both under a single centralized compliance data backbone prevents that error.

TSCA SNUR compliance 2026 timeline showing one finalized substance and 34 proposed

Click on image to view full

Which Compliance Obligations Apply, and When

The obligations differ sharply between the finalized substance and the 34 that remain proposed. Getting this distinction right is the difference between over-reporting and missing a live trigger.

SNUN 90-Day Advance Notice

If finalized, any person intending to manufacture, import, or process one of the covered substances for a designated significant new use must submit a Significant New Use Notice at least 90 days before commencing. This obligation binds only after a substance is final. It is live now for P-22-163 and does not yet bind anyone for the other 34. Submissions use EPA Form 7710-25 via e-PMN, at an estimated $45,496 per submission for large businesses and $14,976 for small businesses, including a $37,000 user fee ($6,480 for qualifying small businesses).

Export Notification Under TSCA Section 12(b)

Export notification is already active for the full batch. The proposed rule ties the Section 12(b) trigger to exports "on or after July 6, 2026." Because that date has passed, exporters of any of these 35 substances already carry a one-time notification obligation per destination country, even for the substances that remain proposed. This is a common gap in supplier and contractor management programs that track only final rules.

Import Certification Under TSCA Section 13

Import certification attaches only to a substance identified in a final SNUR. It applies to P-22-163 upon its September 22, 2026 effective date and does not yet apply to the other 34. Importers of the finalized substance must certify shipment compliance at the border. Automating these controls through audit-ready documentation keeps the certification evidence retrievable.

TSCA SNUR compliance obligation matrix comparing finalized and proposed substances

Click on image to view full

Industries and Product Categories in Scope

The batch reaches across advanced manufacturing sectors, several tied to critical supply chains.

🔋 Batteries and energy storage: P-22-40, P-22-41, P-22-163 (final), the P-22-187 / P-24-88 mixed metal oxide, and the P-24-109 electrolyte salt. This is central to automotive manufacturing supply chains.

💡 Semiconductor and microlithography: nine PBT-flagged photoresist and photolithography entries, relevant to semiconductor and high-tech producers.

🖥 Display materials: the P-24-146 and P-24-148 through P-24-154 cluster, several PBT-flagged.

🔧 Plastics and rubber additives: P-23-105 (the distinct MWCNT entry) and P-24-112 rubber accelerator, common in electronics manufacturing.

🛣 Paving, coatings, and consumer products: P-24-54 through P-24-59, P-24-45, P-23-156, and P-22-158.

Why Article Exemptions Do Not Apply to Most of This Batch

Unlike several other 2026 SNUR batches, most entries here state no article, cured, or matrix exemption. Incorporating a covered substance into a downstream article does not, by itself, relieve the proposed restrictions for the majority of these substances. Several entries impose restricted-use conditions instead: P-24-146 requires liquid-solution-only manufacture, and the paving entries restrict use to chemical intermediates only. The finalized P-22-163 is the exception, carrying the standard cured-article and polymer-matrix exemption unless the matrix is shredded or processed into dust. Screen each substance individually rather than assuming relief, using BOM substance and threshold management to map each material to its specific conditions.

The Screening Problem Across a Multi-Tier Supply Chain

The operational challenge is not understanding one rule. It is checking 35 PMN substances, several with confidential identities, against thousands of parts and supplier declarations. Manual screening in spreadsheets does not scale, and the confidential business information claims mean many substances require a bona fide intent submission to even confirm identity.

This is where multi-tier supply chain transparency matters. Obligations attach to processors and downstream users, not only original manufacturers, so a Tier 2 or Tier 3 input can pull a finished product into scope. Automated supplier data collection and AI document parsing shorten the path from "supplier sent a certificate" to "we know which SKUs are affected." Teams that have moved to a scalable system rather than spreadsheets absorb each new batch without adding headcount.

TSCA SNUR compliance supplier screening workflow for manufacturers

Click on image to view full

Compliance Risks and Enforcement Exposure

TSCA is enforced by EPA, and Section 5 violations can carry civil penalties per day of violation. The practical exposures for this batch are concrete. Importing P-22-163 without Section 13 certification after September 22, 2026 is a border-level compliance failure. Exporting any covered substance without Section 12(b) notification is already a live gap. Beginning a designated new use without a SNUN, once a substance is finalized, means ceasing activity on the effective date and refiling. Continuous compliance monitoring, rather than periodic manual checks, is what surfaces these before they become findings. Proactive risk management turns a reactive scramble into a tracked workflow.

Audit Readiness for Compliance Engineers

SNUR obligations surface across several audit types: internal audits, customer or OEM audits, and EPA regulatory inspections. No software eliminates audit findings. The objective is to be audit-ready, reducing surprises and shortening response time.

That depends on evidence integrity: who submitted a declaration, when it was submitted, and under what authority. Historic state tracking is a data-versioning problem. When an inspector asks which products contained a covered substance as of a specific date, you need time-stamped, point-in-time records, not a rebuilt spreadsheet. Immutable logs and versioned declarations, held in one system of record, make that query answerable in hours rather than weeks.

Strategic Compliance Checklist

✅ 1. Screen suppliers now against all 35 substances, treating P-22-163 as a near-term item.

✅ 2. Prepare P-22-163 controls for Section 13 import certification and Section 12(b) export notification effective September 22, 2026.

✅ 3. Verify export notifications are filed for any covered substance exported on or after July 6, 2026.

✅ 4. Separate the two MWCNT entries (P-22-163 final, P-23-105 proposed) in your material master.

✅ 5. Review P-24-109 carefully, as its narrowed SNUR designates only a subset of conditions.

✅ 6. Do not assume article exemptions, since most entries carry none.

✅ 7. Track docket EPA-HQ-OPPT-2025-2169 for the final rule covering the remaining 34 substances.

How AI Reduces the SNUR Screening Burden

Manual SNUR screening does not keep pace with EPA's rulemaking cadence. AI-native compliance automation changes the economics of this work.

CORA-powered regulatory intelligence monitors TSCA rulemaking, maps new SNUR substances to affected materials, and alerts teams before obligations attach rather than after. CORA-enabled analysis parses supplier certificates, extracts substance data, and flags matches against covered PMN substances, including the confidential-identity cases that require follow-up. By linking those matches to specific products through supplier documentation workflows, compliance teams answer customer and inspector questions at the product level. This shifts the organization from reactive filing toward continuous readiness across the TSCA and PFAS reporting landscape.

Executive Conclusion

The 25-3.5e batch shows how TSCA SNUR compliance now moves at two speeds. One substance is enforceable within weeks, while 34 wait on a separate final rule, and export obligations are already live for the whole batch. For manufacturers with complex bills of materials, the risk is not misreading any single rule. It is failing to screen supplier and product data fast enough to know where obligations attach before a deadline or an audit arrives.

A centralized system of record, continuous regulatory intelligence, and automated supplier screening are what make this manageable at enterprise scale. Request a compliance review to see how Certivo maps these 35 substances to your products and suppliers, and to prepare P-22-163 controls before September 22, 2026.