HS code · 6-digit subheading
HS Code 8421.21 – Machinery; for filtering or purifying water
HS code 8421.21 is the 6-digit subheading for machinery, for filtering or purifying water. It is used for reverse osmosis systems, ultrafiltration units, activated carbon filters, sand filters and UV water purifiers.
What HS 8421.21 covers
This HS code covers machinery specifically designed for filtering or purifying water, a critical category given global concerns about water quality and scarcity. This includes a wide range of equipment from household water filters to large-scale industrial and municipal water treatment plants. Key players in this trade are specialized water treatment equipment manufacturers, engineering firms, and environmental technology suppliers. Importers include municipal water authorities, industrial facilities (e.g., food and beverage, pharmaceutical, chemical), commercial establishments, and individual consumers. The demand is driven by increasing urbanization, industrialization, stricter environmental regulations, and a growing awareness of health and hygiene. Trade often involves advanced filtration technologies such as reverse osmosis, ultrafiltration, and activated carbon systems, with a focus on efficiency, sustainability, and compliance with drinking water standards.
- Covers
- Reverse osmosis systems
- Ultrafiltration units
- Activated carbon filters
- Sand filters
- UV water purifiers
- Industrial water softeners
- Desalination plants
- Sediment filters
- Examples
- Culligan water softeners
- Brita water filters
- GE Water & Process Technologies RO systems
- Siemens Water Technologies
- Pentair water filtration systems
Codes often confused with 8421.21
Common mistake. This code is specific to water filtration/purification, distinguishing it from 842122 (beverage filtration) or 842139 (air/gas filtration), and general pumps in 8413.
Top exporters and importers of HS code 842121, 2025
In 2025, the largest exporter of HS code 842121 in UN Comtrade data was China, with 17% of world exports; the largest importer in UN Comtrade data was the United States, with 16% of world imports. Countries that did not report 2025 data are estimated from partner records, which can understate them.
Top exporters 2025 · share of world exports
- 1 China $2.0B 17% of world exports
- 2 Germany $1.6B 13% of world exports
- 3 United States $1.3B 11% of world exports
World total: $12.3B Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 United States $1.9B 16% of world imports
- 2 Germany $652M 5.5% of world imports
- 3 Canada $448M 3.8% of world imports
World total: $11.9B Reported figures on UN Comtrade ↗
How these figures are built
109 countries reported 2025 trade to UN Comtrade in HS 2022, and their own totals are used. Countries that did not report are estimated from what other countries recorded trading with them. Those estimates miss trade with other non-reporting countries, so they can be low, and a non-reporting country can rank higher than shown or be missing from the list. World totals add both and leave out trade between two non-reporting countries. Figures are in current US dollars; reported imports are mostly valued CIF and exports FOB, and exports include re-exports. The UN Comtrade links show the underlying records; they can also list a few reporters left out here (regional groups and older HS editions).
Source: UN Comtrade (United Nations Statistics Division), 2025 annual data.
Brazil NCM code for 8421.21
Brazil does not split HS 8421.21: its NCM code is 8421.21.00.
All Brazil NCM codes in heading 84.21 →
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text is official; the English is our translation.
Questions about HS 8421.21
What is HS code 842121?
HS code 842121 is a 6-digit subheading in the Harmonized System that covers: Machinery; for filtering or purifying water. This HS code covers machinery specifically designed for filtering or purifying water, a critical category given global concerns about water quality and scarcity. This includes a wide range of equipment from household water filters to large-scale industrial and municipal water treatment plants. Key players in this trade are specialized water treatment equipment manufacturers, engineering firms, and environmental technology suppliers. Importers include municipal water authorities, industrial facilities (e.g., food and beverage, pharmaceutical, chemical), commercial establishments, and individual consumers. The demand is driven by increasing urbanization, industrialization, stricter environmental regulations, and a growing awareness of health and hygiene. Trade often involves advanced filtration technologies such as reverse osmosis, ultrafiltration, and activated carbon systems, with a focus on efficiency, sustainability, and compliance with drinking water standards.
What products fall under HS code 842121?
Reverse osmosis systems, Ultrafiltration units, Activated carbon filters, Sand filters, UV water purifiers, Industrial water softeners, Desalination plants, Sediment filters
What are common misclassifications for HS code 842121?
This code is specific to water filtration/purification, distinguishing it from 842122 (beverage filtration) or 842139 (air/gas filtration), and general pumps in 8413.
Which countries are the top exporters of goods under HS code 842121?
In 2025, the top exporters of HS code 842121 in UN Comtrade data were China ($2.0B, 17% of world exports), Germany ($1.6B) and the United States ($1.3B). World exports came to about $12.3B, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.
Which countries are the top importers of goods under HS code 842121?
In 2025, the top importers of HS code 842121 in UN Comtrade data were the United States ($1.9B, 16% of world imports), Germany ($652M) and Canada ($448M). World imports came to about $11.9B, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.
How is HS code 842121 structured?
HS code 842121 is a 6-digit subheading under the Harmonized System. The first 2 digits (84) identify the chapter, digits 3-4 (21) identify the heading, and digits 5-6 (21) specify the subheading. This code is standardized globally by the World Customs Organization.
What is the Brazil NCM code for HS code 842121?
In Brazil, HS code 842121 is NCM 8421.21.00. The last two digits are 00 because Brazil does not split this HS code further.