Classifying Chemicals and Hazardous Materials

Chemicals are classified mainly in Chapters 28–38 of the Harmonized Tariff Schedule, but importing them triggers a separate layer of EPA, DOT, and OSHA rules that have nothing to do with the tariff code. The classification tells CBP the duty rate; the regulatory layer decides whether the chemical may enter and how it must be certified, labeled, and transported. Importers get into trouble by treating the HTS code as the whole compliance picture. It is not.

Two Systems, Often Confused

Chemical importers juggle two different “classification” systems that share a word but not a purpose:

These are independent. A correct HTS code says nothing about whether your safety data sheet is compliant, and a correct GHS hazard label does not satisfy CBP. Keep them on separate tracks.

Where Chemicals Sit in the HTS

Most chemicals fall in Chapters 28–38 of the schedule — inorganic chemicals (28), organic chemicals (29), pharmaceuticals (30), fertilizers (31), and a range of preparations through Chapter 38. Plastics and rubber sit just after, in Chapters 39–40. Classification turns on chemical composition and function, and the chapter and section notes do heavy lifting here, so read them before settling on a heading. For the underlying method, see how to classify imported goods.

EPA: TSCA Section 13 Import Certification

The biggest federal hurdle for industrial chemicals is the Toxic Substances Control Act (TSCA). Under TSCA Section 13 (implemented at 19 CFR 12.118–12.127, administered by CBP in consultation with EPA), the importer must file a certification with CBP for chemical substances and mixtures:

• Positive certification — the shipment complies with TSCA.
• Negative certification — the shipment is not subject to TSCA (for example, because it is regulated as a pesticide, food, or drug under other statutes).

The certification carries the importer’s name and contact details and is filed electronically with the entry. A chemical that is not on the TSCA Inventory generally cannot be imported for a TSCA use without first clearing EPA’s premanufacture review, so confirm Inventory status well before the goods ship.

DOT and OSHA: Transport and Communication

Two more frameworks attach once a substance is hazardous, and neither is a customs rule:

• DOT / PHMSA hazardous materials regulations (49 CFR Parts 171–180) govern how hazmat is packaged, marked, labeled, and transported in the United States. Classification under the hazmat rules (UN numbers, hazard classes, packing groups) is again separate from the HTS code.
• OSHA Hazard Communication Standard (29 CFR 1910.1200) implements the Globally Harmonized System (GHS) in the U.S. workplace, setting the rules for labels and safety data sheets that travel with the chemical.

A Note on REACH

The EU’s REACH regulation often appears in chemical-import discussions, but it is a requirement for placing chemicals on the European market — it governs U.S. exporters shipping into the EU, not U.S. importers bringing chemicals into the United States. Do not treat REACH as a U.S. import condition. If you both import to the U.S. and sell into the EU, you are managing two distinct regimes.

Build the File Before the Goods Ship

Because admissibility, not the tariff code, is the usual choke point, confirm three things before a chemical shipment leaves: the HTS classification and duty treatment, the TSCA Inventory status and the certification you will file, and the transport and hazard-communication paperwork (DOT shipping description, GHS-compliant labels, and safety data sheets). A gap at any one stops the shipment.

Frequently Asked Questions

Is the HTS code the same as the hazard classification? No. The HTS code is a tariff classification for duty and reporting. Hazard classification under GHS (via OSHA) and under the DOT hazmat rules is a separate exercise for labeling, safety data sheets, and transport.

What is a TSCA import certification? A statement the importer files with CBP for chemical substances, certifying either that the shipment complies with TSCA (positive) or that it is not subject to TSCA (negative). It is required under TSCA Section 13 and 19 CFR 12.118–12.127.

Does REACH apply to chemicals I import into the United States? No. REACH is an EU market-access requirement that applies when you place chemicals on the European market. It does not govern imports into the United States.

How do I know if my chemical is allowed at all? Check whether the substance is on the TSCA Inventory and whether another agency (EPA’s pesticide program, FDA, DEA) also regulates it. A substance off the Inventory generally cannot be imported for a TSCA use without prior EPA review.

Importing chemicals or hazardous materials? Reidel Law Firm prepares flat-fee import/export compliance memos and advises importers on classification and customs compliance with direct attorney access. Get an import compliance memo →