Product classification

HS code for Gas filter: 8421.39

Machinery, for filtering or purifying gases, other than intake air filters, catalytic converters or particulate filters for internal combustion engines.

Classification of gas filter under HS 8421.39

The classification for gas filters falls under HS code 8421.39. Heading 8421 is a broad category covering centrifuges and filtering or purifying machinery and apparatus for liquids or gases. Subheading 8421.39 specifically addresses other machinery for filtering or purifying gases, excluding those used as intake air filters for internal combustion engines (8421.31) or catalytic converters (8421.32). This code includes a diverse array of equipment, from industrial-scale gas scrubbers used in smokestacks to small inline filters used in laboratory gas lines. The primary function must be the removal of solid, liquid, or gaseous impurities from a gas stream. This classification is critical for environmental protection technology and industrial safety equipment, as it distinguishes general gas purification from specialized automotive emission control components. The technology used can range from mechanical mesh and activated carbon to electrostatic precipitation, provided the medium being filtered is a gas.

Covers
  • Industrial gas scrubbers
  • Air purifiers (excluding domestic room units)
  • Inline gas filters for pipelines
  • Chemical vapor filters
  • Electrostatic precipitators for gas cleaning
  • Dust collectors for industrial gas exhaust
Also under 8421.39
  • Camfil air filters
  • AAF Flanders HEPA filters
  • Donaldson industrial filtration systems
  • Parker Hannifin compressed air filters

Codes often confused with 8421.39

Common mistake. The most prevalent error is using 8421.31, which is reserved specifically for intake air filters for internal combustion engines. If the filter is for a factory ventilation system or a gas pipeline, it must be 8421.39. Additionally, 8421.29 is sometimes used by mistake, but that code is for filtering or purifying liquids, not gases. Domestic-type air purifiers are sometimes argued to be 8509 (domestic appliances), but they are generally held to remain in 8421.39 unless they are very small, fan-only units. Catalytic converters must be placed in 8421.32.

8421.31Machinery; intake air filters for internal combustion engines8421.29Machinery; for filtering or purifying liquids, n.e.c. in item no. 8421.285.09Electro-mechanical domestic appliances; with self-contained electric motor, other than vacuum cleaners of heading 85.08.8421.32Machinery; catalytic converters or particulate filters, whether or not combined, for purifying or filtering exhaust gases from internal combustion engines

Top exporters and importers of HS 842139 (the code used for gas filter), 2025

In 2025, the largest exporter of HS 842139 (the code used for gas filter) in UN Comtrade data was Germany, with 17% of world exports; the largest importer in UN Comtrade data was the United States, with 13% of world imports. Countries that did not report 2025 data are estimated from partner records, which can understate them.

Figures cover everything classified under HS 842139, not only gas filter.

Top exporters 2025 · share of world exports

  1. 1 Germany $3.8B
  2. 2 China $3.6B
  3. 3 United States $2.2B

World total: $21.6B Reported figures on UN Comtrade ↗

Top importers 2025 · share of world imports

  1. 1 United States $2.8B
  2. 2 Germany $1.7B
  3. 3 United Kingdom $1.0B

World total: $20.4B 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 codes for gas filter

Brazil splits HS 8421.39 into 3 NCM codes. Pick the one that matches your product:

Source: Siscomex NCM table, updated Oct 2026. The Portuguese text on each NCM page is the official one.

Questions about gas filter

What is the HS code for Gas filter?

The HS code for Gas filter is 842139 (Machinery; for filtering or purifying gases, other than intake air filters, catalytic converters or particulate filters for internal combustion engines). The HS code for general gas filtering or purifying machinery is 8421.39.

How do I classify Gas filter for customs?

Gas filter is classified under HS code 842139 — Machinery; for filtering or purifying gases, other than intake air filters, catalytic converters or particulate filters for internal combustion engines. This is a 6-digit subheading level code.

Does this include filters for car engines?

No, intake air filters for internal combustion engines are classified under HS code 8421.31.

Which countries are the top exporters of gas filter (HS 842139)?

In 2025, the top exporters of HS 842139 (the code used for gas filter) in UN Comtrade data were Germany ($3.8B, 17% of world exports), China ($3.6B) and the United States ($2.2B). World exports came to about $21.6B, 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 gas filter (HS 842139)?

In 2025, the top importers of HS 842139 (the code used for gas filter) in UN Comtrade data were the United States ($2.8B, 13% of world imports), Germany ($1.7B) and the United Kingdom ($1.0B). World imports came to about $20.4B, 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.

Is the HS code for Gas filter the same in all countries?

The base HS code 842139 for Gas filter is internationally standardized for the first 6 digits across 200+ countries. Individual countries may add additional digits for national tariff lines and specific classifications.

What is the NCM code for gas filter in Brazil?

Brazil splits HS 842139 into 3 NCM codes, so the right one for gas filter depends on the product's details: 8421.39.10 (Electrostatic filters for gases), 8421.39.30 (Oxygen concentrators, 6 l/min or less), 8421.39.90 (Other gas filtering or purifying machinery).