Chapter 2833 — Customs Tariff Headings

2833.2Other sulphates:

2833.30.00Alums

2833.40.00Peroxosulphates (persulphates)

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Products classified under Tariff item 28.33

Anhydrous Sodium Sulfate

Pure disodium sulfate (Na2SO4) in anhydrous form, a chemically defined inorganic salt used in industrial processes. This falls under tariff item 2833.11.00 as disodium sulfate.

Glass Batch Salt Cake Additive

Granular salt cake incorporated into glass batch compositions as a fining agent and viscosity modifier. This technical grade disodium sulfate, known commercially as salt cake, is a separate chemically defined compound of Chapter 28.

Glass Manufacturing Sodium Sulfate

Calcined synthetic Na2SO4 flux for flat glass production, reducing melting point. This is a separate chemically defined compound of Chapter 28.

Industrial Salt Cake for Glass Manufacturing

Coarse-grained salt cake used primarily as a flux in flat glass production to lower melting temperatures of silica. This is a technical grade of disodium sulfate, a chemically defined inorganic compound.

Kraft Pulping Grade Salt Cake

Technical sodium sulfate (salt cake) used in sulfate pulp mills to regenerate cooking liquor during kraft paper production. This is a separate chemically defined compound of Chapter 28.

Laboratory Reagent Sodium Sulfate

ACS-grade disodium sulfate for analytical chemistry and water testing labs. This is a pure compound under Chapter 28, specifically disodium sulfate.

Paper Pulping Sodium Sulfate

Recovered synthetic Na2SO4 from kraft process makeup, pure disodium sulfate. This is a separate chemically defined compound of Chapter 28.

Pharmaceutical Grade Sodium Sulfate

USP-grade disodium sulfate anhydrous for use in laxative formulations and IV solutions. This is a strictly chemically defined compound under Chapter 28.

Pharmaceutical Intermediate Salt Cake

Technical grade salt cake serving as salting-out agent in protein precipitation for biotech pharmaceutical production. This is disodium sulfate, a separate chemically defined compound.

Salt Cake By-Product from HCl Production

Crystalline salt cake generated as waste from the Mannheim process for hydrochloric acid manufacture from sodium chloride. This is disodium sulfate, a separate chemically defined compound.

Salt Cake (Sodium Sulfate Anhydrous)

Salt cake is the commercial name for disodium sulfate (Na2SO4) in its anhydrous form, produced as a by-product in chemical manufacturing processes like hydrochloric acid production. It is a separate chemically defined compound.

Sodium Sulfate Decahydrate (Glauber's Salt)

Disodium sulfate decahydrate (Na2SO4·10H2O), known as Glauber's salt, a hydrated form chemically defined under Chapter 28. This falls under tariff item 2833.11.00 as disodium sulfate.

Technical Grade Salt Cake for Detergent Production

Salt cake serving as filler and processing aid in powdered laundry detergent formulations, providing bulk and flow properties. This is disodium sulfate, a separate chemically defined compound.

Technical Grade Sodium Sulfate

High-purity synthetic disodium sulfate for industrial detergents and paper pulping. This is a separate chemically defined compound of Chapter 28.

Textile Dyeing Salt Cake

Coarse salt cake used as mordant and leveling agent in reactive dyeing of cotton and cellulosic fibers. This is disodium sulfate, a separate chemically defined compound.

2833.19.00

Sodium Sulfate Anhydrous (Salt Cake)

Sodium sulfate anhydrous, also known as salt cake, is a white crystalline powder used primarily as a filler and fluxing agent in the glass, paper, and detergent industries. It is a separate chemically defined compound of sodium and sulfur, falling under tariff item 2833.19.00 as 'Other' sodium sulfates. This product is not a polysulphide and does not contain organic stabilizers, aligning with the chapter's scope for inorganic chemicals.

2833.19.00

Sodium Sulfate Decahydrate Technical Grade

Sodium sulfate decahydrate technical grade is a hydrated form of sodium sulfate, commonly used in heat packs and as a laboratory reagent. It is a separate chemically defined compound with water of crystallization, fitting the description of 'other' sodium sulfates under tariff item 2833.19.00. The product does not meet the criteria for Glauber's salt purity or form, but remains within the chapter's scope as an inorganic sulfate.

Anhydrous Magnesium Sulfate

Anhydrous magnesium sulfate (MgSO4) is a dry, white powder used as a desiccant in laboratories and pharmaceutical manufacturing. It is a separate chemically defined compound of magnesium, falling squarely within heading 28.33 as an 'other sulfate' of magnesium. The product is not excluded by Chapter 28 notes, as it contains no organic constituents or added substances that would alter its classification.

Epsom Salt Flakes for Spa Use

Epsom salt flakes for spa use consist of magnesium sulfate heptahydrate (MgSO4·7H2O) in flake form, designed to dissolve readily in bath water. As a chemically defined inorganic sulfate of magnesium, it is classified under tariff item 2833.21.00. The product contains no added perfumes, oils, or organic substances that would remove it from Chapter 28.

Food Grade Magnesium Sulfate

Food grade magnesium sulfate is a purified, FCC-grade chemical used as a firming agent in canned vegetables and as a nutrient supplement. It is a chemically defined magnesium sulfate meeting the requirements of Chapter 28 Note 1, with no organic or other added substances. The product is classifiable under tariff item 2833.21.00 as an 'other sulfate' of magnesium.

Lab Grade Magnesium Sulfate Desiccant

Lab grade anhydrous magnesium sulfate is a granular desiccant used in organic chemistry to dry solvents. It is a chemically defined compound of magnesium, free of organic stabilizers, and falls under tariff item 2833.21.00. The granular form results from prior firing to remove water, but it remains a simple sulfate.

Magnesium Sulfate for Fireworks

High-purity magnesium sulfate for fireworks is a granular, chemically defined compound used as an oxidizer in pyrotechnic formulations. It falls under tariff item 2833.21.00 as a sulfate of magnesium, with no organic or metallic additives. The product is supplied in a form suitable for safe industrial handling.

Magnesium Sulfate Heptahydrate (Epsom Salt)

Magnesium sulfate heptahydrate, commonly known as Epsom salt, is a chemically defined inorganic salt with the formula MgSO4·7H2O. It is used in bath salts, agricultural applications, and pharmaceutical preparations. As a simple sulfate of magnesium, it is classifiable under tariff item 2833.21.00, provided it contains no added organic or cosmetic substances.

Magnesium Sulfate in Bulk for Agriculture

Bulk kieserite (MgSO4·H2O) is a monohydrate form of magnesium sulfate used for soil magnesium correction in agriculture. It is a chemically defined inorganic sulfate of magnesium, classifiable under tariff item 2833.21.00. The product is supplied in 50 kg bags for large-scale application, without any fertilizer additives.

Magnesium Sulfate Monohydrate

Magnesium sulfate monohydrate (MgSO4·H2O), also known as kieserite, is used in fertilizers and animal feed supplements. It is a chemically defined sulfate of magnesium, falling under tariff item 2833.21.00. The product is free of organic stabilizers and is not excluded by Chapter 28 notes.

Pharmaceutical Grade Magnesium Sulfate

Pharmaceutical grade magnesium sulfate is a purified heptahydrate used in IV solutions and medical applications. It is a chemically defined magnesium sulfate, meeting USP standards, and falls under tariff item 2833.21.00. The product contains no organo-inorganic compounds or other substances that would exclude it from Chapter 28.

Technical Grade Magnesium Sulfate

Technical grade magnesium sulfate heptahydrate is used in industrial processes such as paper production and textile manufacturing. It is a chemically defined sulfate of magnesium, classifiable under tariff item 2833.21.00. The product has lower purity than pharmaceutical grades but remains a simple inorganic compound.

Alum Cake (Aluminum Sulfate Byproduct)

Alum cake is a solid byproduct of aluminum sulfate from water treatment processes, containing the chemically defined compound Al2(SO4)3. It is classified under tariff item 2833.22.00 as an aluminum sulfate, regardless of its byproduct origin, provided it meets the purity and form criteria of Chapter 28.

Aluminum Ammonium Sulfate (Ammonium Alum)

Aluminum ammonium sulfate (NH4Al(SO4)2·12H2O), or ammonium alum, is a double salt of aluminum and ammonium. Under Chapter 28 Note 5, double salts are classified in heading 28.42, not as an aluminum sulfate, so this product does not belong under tariff item 2833.22.00.

Aluminum Sulfate Octadecahydrate

Aluminum sulfate octadecahydrate (Al2(SO4)3·18H2O) is a chemically defined hydrate of aluminum sulfate, used as a coagulant in water purification. Hydrates of inorganic compounds are covered by Chapter 28 Note 1(a) and (b), and the aluminum sulfate core places it under tariff item 2833.22.00.

Anhydrous Aluminum Sulfate

Anhydrous aluminum sulfate (Al2(SO4)3) is the dehydrated form of the aluminum salt, used in paper sizing and flame retardants. As a chemically defined sulfate of aluminum, it falls squarely under tariff item 2833.22.00, with no exclusions in Chapter 28.

Flame Retardant Aluminum Sulfate Powder

Flame retardant aluminum sulfate powder is a fine powder of aluminum sulfate used in flame retardant formulations. As long as it is a chemically defined aluminum sulfate without additional flame retardant agents, it is classified under tariff item 2833.22.00. If it contains other active ingredients, it may be a preparation.

Granular Aluminum Sulfate for Paper Sizing

Granular aluminum sulfate for paper sizing is a pure aluminum sulfate in granular form, used in rosin sizing. The physical form (granular) does not affect classification, and as a chemically defined sulfate of aluminum, it falls under tariff item 2833.22.00.

Liquid Aluminum Sulfate Solution 48%

Liquid aluminum sulfate solution at 48% concentration is an aqueous solution of aluminum sulfate. Chapter 28 Note 1(b) covers products dissolved in water, so this solution is classifiable under tariff item 2833.22.00, provided the solution is a normal method of putting up for transport or safety.

Pharmaceutical Grade Aluminum Sulfate

Pharmaceutical grade aluminum sulfate is a high-purity aluminum sulfate meeting USP standards, used in topical astringents. Purity does not affect classification; as a chemically defined sulfate of aluminum, it falls under tariff item 2833.22.00, unless it is put up in measured doses for retail sale, which would shift it to Chapter 30.

Technical Grade Aluminum Sulfate

Technical grade aluminum sulfate, typically 17% Al2O3 basis, is a chemically defined sulfate of aluminum used as a flocculant in water treatment. The technical grade designation does not affect classification, and it falls under tariff item 2833.22.00 as an aluminum sulfate.

Anhydrous Nickel Sulfate

Anhydrous nickel sulfate (NiSO4) is a yellow-brown powder used in high-temperature applications such as glass coloring and catalyst production. It is a separate chemically defined compound of nickel, meeting the criteria of Chapter 28 Note 1(a). It falls under tariff item 2833.24.00 as a sulfate of nickel.

Electrowinning Grade Nickel Sulfate

Electrowinning grade nickel sulfate is a high-purity form of nickel sulfate used in the electrowinning process to recover nickel metal from ores. It is a chemically defined nickel sulfate compound, classifiable under tariff item 2833.24.00 as a sulfate of nickel.

Nickel Ammonium Sulfate

Nickel ammonium sulfate is a double salt of nickel and ammonium sulfate, used in analytical chemistry and electroplating. Under Chapter 28 Note 5, double salts are classified in heading 28.42, not 28.33. Therefore, it does not fall under tariff item 2833.24.00.

Nickel(II) Sulfate USP Grade

USP-grade nickel(II) sulfate is a chemically defined nickel sulfate meeting pharmaceutical standards for trace element supplements and lab standards. It is a separate chemically defined compound of nickel, classifiable under tariff item 2833.24.00, provided it is not put up in measured doses or for retail sale (Chapter 30 Note 2).

Nickel Sulfate Crystals EP Grade

Nickel sulfate crystals EP grade are high-purity nickel sulfate crystals for calibration standards and research. As a chemically defined nickel sulfate, it meets Chapter 28 Note 1(a) and is classifiable under tariff item 2833.24.00.

Nickel Sulfate for Lithium-Ion Battery Cathodes

Battery-grade nickel sulfate hexahydrate (NiSO4·6H2O) is a high-purity precursor for NMC cathode materials in lithium-ion batteries. It is a separate chemically defined compound of nickel, meeting Chapter 28 Note 1(a). It falls under tariff item 2833.24.00 as a sulfate of nickel.

Nickel Sulfate Hexahydrate

Nickel sulfate hexahydrate (NiSO4·6H2O) is a bright green crystalline compound used in electroplating and chemical synthesis. It is a separate chemically defined compound of nickel, meeting Chapter 28 Note 1(a). It falls under tariff item 2833.24.00 as a sulfate of nickel.

Technical Grade Nickel Sulfate Solution 20%

A 20% aqueous solution of nickel sulfate for industrial cleaning and nickel plating preparation. Under Chapter 28 Note 1(b), products dissolved in water are covered by the chapter. It falls under tariff item 2833.24.00 as a sulfate of nickel.

Anhydrous Copper Sulfate Powder

Anhydrous copper sulfate (CuSO4) in white powder form, without water of hydration. It is a separate chemically defined compound of copper, falling under tariff item 2833.25.00 as 'other sulphates of copper'.

Copper(II) Sulfate for Aquaculture

Technical grade copper sulfate crystals used for aquaculture pond algae control. As a chemically defined copper sulfate, it is classified under tariff item 2833.25.00 regardless of its end use in water treatment.

Copper Sulfate Pentahydrate Crystals

Copper sulfate pentahydrate (CuSO4·5H2O) in blue crystalline form, used as a fungicide and in laboratory applications. This hydrated form is a separate chemically defined compound of copper, classified under tariff item 2833.25.00.

Copper Vitriol Blue Crystals

Copper vitriol, the traditional name for copper sulfate pentahydrate, presented as deep blue crystals for pigment and dye applications. It is chemically identical to copper sulfate pentahydrate and classified under tariff item 2833.25.00.

Electroplating Grade Copper Sulfate

Refined copper sulfate for electroplating baths, with high purity for uniform metal deposition. As a chemically defined copper sulfate, it falls under tariff item 2833.25.00, even though it is optimized for a specific industrial use.

Feed Grade Copper Sulfate Monohydrate

Feed grade copper sulfate monohydrate (CuSO4·H2O) with controlled particle size for livestock mineral supplements. This chemically defined copper sulfate is classified under tariff item 2833.25.00, with feed grade specifications affecting only purity, not classification.

Laboratory Grade Copper Sulfate

Laboratory grade copper sulfate pentahydrate (ACS reagent grade) for analytical and educational use. As a high-purity chemically defined compound, it is classified under tariff item 2833.25.00, with purity levels not affecting the tariff classification.

Technical Grade Copper Sulfate

Technical grade copper sulfate pentahydrate with 98% minimum purity, used for large-scale fungicide and nutrient applications. This chemically defined copper sulfate is classified under tariff item 2833.25.00, regardless of its industrial purity grade.

Ultrahigh Purity Copper Sulfate

Ultrahigh purity copper sulfate (99.999%) for semiconductor doping and advanced materials research. This chemically defined copper sulfate is classified under tariff item 2833.25.00, as electronic grade purity does not change the classification.

Barium Sulfate Lithopone Precursor

High-assay barium sulfate used as a precursor in lithopone production, where it is co-precipitated with zinc sulfide to create white pigments. This product is a separate chemically defined compound of barium, falling under tariff item 2833.27.00 as a barium sulfate, prior to any complexing or mixing.

Barium Sulfate Powder (Precipitated)

High-purity precipitated barium sulfate (BaSO4) used as a white pigment in paints, coatings, and plastics. It is a separate chemically defined compound of barium, meeting the criteria of Chapter 28 Note 1, and is classified under tariff item 2833.27.00 as a barium sulfate.

Barium Sulfate USP Grade

Pharmaceutical-grade barium sulfate used as a radio-opaque contrast medium in X-ray imaging. This product is a pure, chemically defined barium sulfate meeting the requirements of Chapter 28 Note 1, and is classified under tariff item 2833.27.00 as a barium sulfate.

Barytes Precipitated Filler Grade

Micronized precipitated barium sulfate used as a functional filler in rubber, plastics, and tires for reinforcement and opacity. It is a separate chemically defined inorganic compound of barium, classified under tariff item 2833.27.00 as a barium sulfate.

Blanco Barium Sulfate Pigment

Synthetic barium sulfate pigment known as 'Blanco' or permanent white, used in high-end paints and artist oils for opacity. This product is a chemically defined barium sulfate under tariff item 2833.27.00, distinguished from natural barytes by its synthetic origin and purity.

Pharmaceutical Barium Meal Suspension Base

Sterile barium sulfate powder base for preparing oral contrast suspensions in gastrointestinal X-rays. This product meets USP standards as a chemically defined barium sulfate under tariff item 2833.27.00, as it is not yet put up in measured doses or for retail sale.