TSCA Chemical Inventory & PMN: the US chemical compliance stack

Layer 0 is the TSCA Inventory: ~86,000 listed substances, split active vs inactive after the 2018 Inventory Reset Rule. Anything not on the active inventory is a 'new chemical' requiring a Section 5 PMN (90-day statutory review, in practice longer) and an affirmative EPA determination before commercial manufacture or import. Significant New Use Rules (SNURs) extend Section 5 obligations to existing chemicals when used in significant new ways. Layer 1 is Section 8(a) Chemical Data Reporting — every four years, manufacturers and importers of listed substances above the 25,000 lb/site threshold (2,500 lb for substances subject to certain rules) report production volumes, processing/use data, and worker exposure information. Layer 2 is Section 6 risk evaluation and management — EPA's prioritisation, risk evaluation and risk management workflow on the 'first ten' (PCE, TCE, methylene chloride, asbestos, etc.) and subsequent rounds, with workplace chemical protection programmes flowing into facility EH&S systems. Layer 3 is Section 13 import certification (positive or negative TSCA certificate at every CBP entry) and Section 12(b) export notifications.

A Section 5 PMN is required at least 90 days before US commercial manufacture or import of any chemical not on the active TSCA Inventory. EPA reviews physical/chemical properties, environmental fate, ecotoxicity, human health hazard, exposure and use scenarios. Post-Lautenberg, EPA must issue an affirmative determination — 'not likely to present an unreasonable risk', 'may present an unreasonable risk' (typically resulting in a 5(e) Consent Order with use restrictions, worker PPE, hazard communication), or 'insufficient information' (5(e) order). After commercialisation, EPA typically issues a SNUR to extend the 5(e) restrictions to other manufacturers/importers. The Low Volume Exemption (LVE, ≤10,000 kg/yr) and Low Release and Exposure Exemption (LoREX) provide expedited pathways for qualifying chemicals. Polymer Exemption (40 CFR 723.250) covers most polymers meeting two-of-three criteria (number-average MW, oligomer content, reactive functional groups).

Chemical Data Reporting under 40 CFR Part 711 collects manufacturing, processing and use data on TSCA Inventory chemicals every four years. The 2024 CDR cycle (data year 2020-2023) required reports for sites manufacturing ≥25,000 lb/yr of a listed substance, with the 2,500 lb threshold for substances subject to TSCA orders/rules. Reports cover production volume, physical form, intended use (industrial, commercial, consumer), end-use category, number of workers exposed, maximum concentration, and downstream commercial/consumer use data. EPA increasingly uses CDR data to prioritise Section 6 risk evaluations — under-reporting or substance miscoding has compliance and downstream-risk consequences.

EPA's Section 6 workflow prioritises substances as High-Priority or Low-Priority, then runs risk evaluation against conditions of use, then issues risk-management rules. First-ten substances (asbestos, 1-bromopropane, carbon tetrachloride, HBCD, methylene chloride, NMP, PCE, PV29, TCE, trichloroethylene) have published rules including workplace chemical protection programmes (WCPP) with action levels, exposure limits, monitoring, regulated areas, PPE, and exposure controls. Subsequent rounds cover additional substances. WCPP requirements flow into facility EH&S programmes (OSHA HazCom, respirator program, exposure monitoring) and create downstream-customer notification obligations.

Section 13 requires a TSCA certification at every CBP import entry: a positive certification ('the chemicals in this shipment comply with all applicable TSCA rules') or, where applicable, a negative certification (substance not subject to TSCA, e.g., FFDCA-regulated). Brokers cannot certify on the importer's behalf without proper authorisation. Articles are generally not certified except when subject to a specific rule (e.g., the PIP (3:1) processing rule). Section 12(b) requires a one-time-per-country export notification when exporting any substance subject to a Section 4, 5, 6 or 7 action — submitted within 7 days of the first shipment to that country or before the first shipment if known.

Maintain a current substance master with TSCA Inventory status (active/inactive), PMN/LVE/Polymer Exemption identifiers, SNUR citations, Section 6 risk-evaluation status and CDR reporting threshold flags. Run a Section 5 PMN workflow with EPA correspondence, e-PMN submission tracking and 5(e) consent-order tracking. Run a four-year CDR cycle with site-level production-volume aggregation. Wire Section 13 import certificates and Section 12(b) export notifications into shipment processes. Treat new-supplier substance changes (different CAS, different impurity profile, different polymer composition) as triggering re-verification — a 'same' chemical from a new source may not be on the inventory.