CLA-2-84:OT:RR:NC:N1:105
Marie-Pierre Seguin
Biothermica
426 Rue Sherbrooke East
Montreal, QC H2L 1J6
Canada
RE: The tariff classification of regenerative thermal oxidizer units from Canada
Dear Ms. Seguin:
In your letter dated May 26, 2025, you requested a tariff classification ruling.
The items under consideration are described as Ventilation Air Methane Oxidation (VAMOX) systems,
which are regenerative thermal oxidizer (RTO) units specifically engineered to reduce methane emissions
from underground coal mines. The unit encompasses a full plant, which includes the RTO unit, a centrifugal
fan, ventilation ducting, a control office, and a compressor room, all of which will be imported together. The
VAMOX unit has a ceramic, fiber-lined, carbon steel outer skin. All internal parts of the system are
accessible including the burner components that are reachable via a maintenance platform.
Through the process of high-temperature thermal oxidation, methane is converted to carbon dioxide and
water vapor that allows for the recycling of released energy. The VAMOX system uses ceramic heat transfer
beds as heat exchangers that are coupled to a retention chamber where methane particles are oxidized to
recover as much energy as possible (90-95%) from the oxidation process. The contaminant-free air is then
exhausted into the atmosphere through a chimney. The primary function of the unit is to purify the ventilation
air emitted by the underground coal mine to reduce its environmental impact.
We consider the regenerative thermal oxidizer units to be similar to the merchandise in New York ruling NY
R05112 (dated November 20, 2006) and Headquarters Ruling H118895 (dated April 9, 2012). The rulings
covered standard regenerative thermal oxidizer units and thermal oxidizer units used for purification of
industrial process exhausts. CBP found that the units were classified under heading 8421, Harmonized Tariff
Schedule of the United States (HTSUS). While the size and control functions of the VAMOX have been
specifically designed and adapted for the purpose of purifying the ventilation air methane from underground
coal mines, we find that the primary function is similar to standard regenerative thermal oxidizer units.
The applicable subheading for the VAMOX systems will be 8421.39.0190, HTSUS, which provides for
“Centrifuges, including centrifugal dryers; filtering or purifying machinery and apparatus, for liquids or
gases; parts thereof: Filtering or purifying machinery and apparatus for gases: Other: Other: Other: Other.”
The general rate of duty will be free.
Products of Canada as provided by heading 9903.01.10 in Section XXII, Chapter 99, Subchapter III, U.S.
Note 2(j), HTSUS, other than products classifiable under headings 9903.01.11, 9903.01.12, 9903.01.13,
9903.01.14, and 9903.01.15, HTSUS, will be subject to an additional 25 percent ad valorem rate of duty. At
the time of entry, you must report the applicable Chapter 99 heading, i.e. 9903.01.10, in addition to
subheading 8421.39.0190, HTSUS, listed above. Articles that are entered free of duty under the terms of
general note 11 to the HTSUS (U.S.-Mexico-Canada Agreement (USMCA)), including any treatment set
forth in subchapter XXIII of Chapter 98 and subchapter XXII of chapter 99 of the HTSUS, will not be
subject to the additional ad valorem duties provided for in heading 9903.01.10. If your product is entered
duty free as originating under the USMCA, you must report heading 9903.01.14, HTSUS, in addition to
subheading 8421.39.0190.
Effective April 5, 2025, Executive Orders implemented “Reciprocal Tariffs.” All imported merchandise
must be reported with either the Chapter 99 provision under which the reciprocal tariff applies or one of the
Chapter 99 provisions covering exceptions to the reciprocal tariffs. At this time products from all countries
will be subject to an additional 10 percent ad valorem rate of duty. Your product falls within an excepted
subheading. At the time of entry, you must report the Chapter 99 heading applicable to your product
classification, i.e. 9903.01.26, in addition to subheading 8421.39.0190, HTSUS, listed above.
The tariffs and additional duties cited above are current as of this ruling’s issuance. Duty rates are provided
for your convenience and are subject to change. The text of the most recent HTSUS and the accompanying
duty rates are provided at https://hts.usitc.gov/.
The holding set forth above applies only to the specific factual situation and merchandise description as
identified in the ruling request. This position is clearly set forth in Title 19, Code of Federal Regulations
(CFR), Section 177.9(b)(1). This section states that a ruling letter is issued on the assumption that all of the
information furnished in the ruling letter, whether directly, by reference, or by implication, is accurate and
complete in every material respect. In the event that the facts are modified in any way, or if the goods do not
conform to these facts at time of importation, you should bring this to the attention of U.S. Customs and
Border Protection (CBP) and submit a request for a new ruling in accordance with 19 CFR 177.2.
Additionally, we note that the material facts described in the foregoing ruling may be subject to periodic
verification by CBP.
This ruling is being issued under the provisions of Part 177 of the Customs and Border Protection
Regulations (19 C.F.R. 177).
A copy of the ruling or the control number indicated above should be provided with the entry documents
filed at the time this merchandise is imported. If you have any questions regarding the ruling, please contact
National Import Specialist Jason Christie at [email protected].
Sincerely,
(for)
Steven A. Mack
Director
National Commodity Specialist Division