HSChapter 84
U.S. imports of water filtering & purifying machinery and apparatus (HS 842121) totaled $166.0M in April 2026, traded with 57 countries.
Importers of Water Filtering & Purifying Machinery and Apparatus paid $15.5M in duties in April 2026 — an effective duty rate of 13% on $118.9M in dutiable value, based on actual customs collections rather than the published tariff schedule.
Last updated: April 2026 dataWater filtration and purification equipment — from municipal treatment systems and industrial process water units to point-of-entry commercial systems — enters under the single US line 8421210000. Canada and Mexico are the leading import sources, consistent with deep North American supply-chain integration in water treatment infrastructure, with China, South Korea, and Germany also significant. This heading is distinct from apparatus that purifies water by UV or chemical dosing alone; the classification turns on whether the equipment mechanically filters or physically purifies the water stream. Importers should also be aware that certain water treatment systems may require EPA or state-level regulatory review depending on their intended application.
AI-written summary of the official U.S. Census Bureau trade figures on this page — verify before relying on it.
Yes — reverse osmosis systems that filter or purify water by forcing it through a semi-permeable membrane are generally classified under 8421210000 as water filtering or purifying machinery. The membrane-based separation is considered a filtering/purifying process for HTS purposes. However, if the RO unit is integrated into a larger system with a primary function other than water purification, the classification of the complete system may differ, and a principal-function analysis would apply.
Heading 842121 is specifically limited to water filtering and purifying machinery. Equipment designed to filter or purify other liquids — oils, beverages, chemicals — classifies under different subheadings within heading 8421 (such as 842129 for other liquid filtering/purifying apparatus). The nature of the liquid the equipment is designed to process is the controlling distinction, not the filtration technology used.
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| Country | Imports | Exports | Balance |
|---|---|---|---|
| CANADA | $23.3M | $27.1M | +$3.9M |
| MEXICO | $21.1M | $11.2M | -$9.9M |
| CHINA | $24.2M | $6.7M | -$17.4M |
| KOREA, SOUTH | $17.2M | $3.6M | -$13.6M |
| JAPAN | $10.4M | $1.7M | -$8.6M |
Monthly import values over time
HS10 import codes under this HS6 parent. Source: U.S. Harmonized Tariff Schedule.
| Code | Description | Import Value | Effective Tariff % | Duty Collected |
|---|---|---|---|---|
| 8421210000 | WATER FILTERING OR PURIFYING MACHINERY & APPARATUS | $166.0M | 13.01% | $15.5M |
WATER FILTERING OR PURIFYING MACHINERY & APPARATUS
HS10 export codes under this HS6 parent. Source: U.S. Schedule B export classification.
| Code | Description | Export Value |
|---|---|---|
| 8421210000 | WATER FILTERING OR PURIFYING MACHINERY & APPARATUS | $96.8M |
WATER FILTERING OR PURIFYING MACHINERY & APPARATUS
2.0M no
DIGITAL PROCESSING UNITS, N.E.S.O.I.
HS 847150
PARTS & ACCESSORIES FOR ADP MACHINES & UNITS
HS 847330
PORT DIGTL AUTOMATIC DATA PROCESS MACH NOT > 10 KG
HS 847130
AUTOMATIC DATA PROCESSING STORAGE UNITS, N.E.S.O.I
HS 847170
AUTOMATIC DATA PROCESSING UNITS, N.E.S.O.I.
HS 847180
TURBOJET AND TURBOPROLLER PARTS
HS 841191
| State | Imports | Exports | Balance |
|---|---|---|---|
| California | $38.1M | $16.3M | -$21.8M |
| Texas | $18.3M | $6.9M | -$11.4M |
| Pennsylvania | $17.3M | $4.4M | -$12.9M |
| Port | Imports | Exports | Balance |
|---|---|---|---|
| LOS ANGELES, CA | $29.2M | $9.1M | -$20.1M |
| PORT HURON, MI | $12.0M | $5.6M | -$6.4M |
| LONG BEACH, CA | $9.7M | $6.9M | -$2.8M |