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Updated September 19, 2026

What is the HTS code for underground plastic storm water chambers?

HTS code

3926.90.9989

CBP classified plastic storm water management chambers, made of fiberglass reinforced thermosetting plastic and installed underground to handle excess water from large storms, under HTS 3926.90.9989 in ruling N353580. That line covers other articles of plastics that no other heading describes more specifically.

  • Made in Canada
  • CBP ruling N353580
  • October 3, 2025
  • Current
Today's duty from Canada

The Product

  • Hydro Chain Chambers, Models S-22 and M-6, made of fiberglass reinforced thermosetting plastic.
  • Designed to be installed underground to handle excess water from large storm events.
  • A complete system is made up of several thousand chambers.
  • Each S-22 chamber holds 161 gallons; each M-6 chamber holds 41 gallons.

CBP's Ruling

ItemHTS codeCBP's description of the line
Hydro Chain Chambers, Models S-22 and M-6HTS 3926.90.9989[o]ther articles of plastics and articles of other materials of headings 3901 to 3914: [o]ther: [o]ther: [o]ther

Explanation

CBP found the chambers are articles of plastic, and that no other heading provides for them more specifically. That puts them in heading 3926, other articles of plastics.

Within the heading, CBP placed them on 3926.90.9989, the line for other articles of plastics not named elsewhere in the heading; the chambers are made of fiberglass reinforced thermosetting plastic.

Does this apply to your product?

It likely does if you can answer yes to each of these:

  • Is it made of fiberglass reinforced thermosetting plastic?
  • Is it a chamber installed underground to handle excess water from storms?
  • Is it used as part of a storm water management system built from many chambers?

A no to any of them can mean a different code. A licensed broker can classify your product.

The code today

HTS codeIn today's scheduleWhere it sitsToday's duty
3926.90.9989✓ Still in the scheduleHeading 3926Today's duty from Canada 

Checked against today's tariff schedule. The duty calculator opens with the code and country filled in.

Related rulings

N357592, N341646 and N357063 put a plastic jewelry storage system, plastic shade canopies and a plastic clamping tool on the same line. N355154 covers a plastic cupholder and N352779 covers plastic castration assisting tools.

  • N355154November 7, 2025Plastic cupholder from Canada3926.90.9989
  • N326584June 27, 2022Plastic lawn border from Canada3926.90.9985
  • N340673July 3, 2024Plastic water bottle from China3926.90.9985
  • N352779September 11, 2025Plastic castration assisting tools from Canada3926.90.9989
  • N357592January 22, 2026Plastic jewelry storage system from China3926.90.9989
  • N339565April 23, 2024Plastic portable water pet bowls and pencils from China with logos added in Mexico3926.90.9985, 9609.10.0000, 9802.00.50
  • N341646August 21, 2024The classification, country of origin, and eligibility of the United States-Mexico-Canada Trade Agreement (USMCA) of plastic shade canopies3926.90.9989
  • N357063January 12, 2026The classification, marking, country of origin, and United States-Mexico-Canada Trade Agreement (“USMCA”) eligibility of a plastic clamping tool3926.90.9989
Read CBP's full ruling N353580 The letter as CBP published it, on rulings.cbp.gov

Borderless, a licensed U.S. customs brokerage, summarized CBP ruling N353580 in plain English and checked its codes against the letter and today's tariff schedule. A ruling applies only to goods that match its facts; our terms explain the rest. Terms