Ferrous Sulfate Heptahydrate

Ferrous sulfate heptahydrate (FeSO4·7H2O) is a pale green crystalline compound used primarily as a nutrient supplement in agriculture and water treatment. It falls under HTS 2833.29.20.00 as a sulfate of iron, specifically classified among other iron sulfates due to its chemical definition as an inorganic iron salt.

Import Duty Rates by Country of Origin

Origin CountryMFN RateCh.99 SurchargesTotal Effective Rate
🇨🇳ChinaFree+35.0%35%
🇲🇽MexicoFree+10.0%10%
🇨🇦CanadaFree+10.0%10%
🇩🇪GermanyFree+10.0%10%
🇯🇵JapanFree+10.0%10%

Alternative Classifications

This product could be classified differently depending on its characteristics or intended use.

3102.60.00Lower: 25% vs 35%

If when blended into NPK fertilizers

Fertilizer mixtures containing iron sulfates are classified in Chapter 31, not as pure chemical compounds.

3824.99Lower: 15% vs 35%

If chemically defined but prepared for specific industrial use

Certain prepared chemical products fall under 3824 if not purely meeting Chapter 28 definitions.

2833.21.00Lower: 28.7% vs 35%

If the primary cation is copper rather than iron

Copper sulfate (CuSO4) uses a different subheading within the same sulfate category.

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Import Tips & Compliance

Verify purity and hydration state via lab analysis to confirm classification under iron sulfates

Include Material Safety Data Sheets (MSDS) showing iron content to avoid misclassification as a mixture

Check for agricultural use declarations if destined for fertilizers to comply with USDA import rules

Related Products under HTS 2833.29.20.00

Ferric Sulfate Anhydrous

Ferric sulfate (Fe2(SO4)3) in anhydrous form is a yellow to brown powder used in water purification and as a coagulant. Classified under HTS 2833.29.20.00 as an other sulfate of iron, meeting Chapter 28 criteria for chemically defined inorganic iron compounds.

Iron(II) Sulfate Monohydrate

Iron(II) sulfate monohydrate (FeSO4·H2O), also known as melanterite, serves as a reducing agent and iron supplement in animal feed. It is classified under HTS 2833.29.20.00 for iron sulfates, excluding those specified elsewhere in the chapter.

Ferric Ammonium Sulfate

Ferric ammonium sulfate ((NH4)Fe(SO4)2·12H2O) is used in analytical chemistry and as a mordant in dyeing. It qualifies under HTS 2833.29.20.00 as a sulfate of iron, treated as a metal salt per Chapter 28 notes on complex salts.

Copperas Crystals (Ferrous Sulfate)

Copperas, or green vitriol, refers to large crystals of ferrous sulfate heptahydrate used in gardening and pigment production. Classified in HTS 2833.29.20.00 as other sulfates of iron, distinct from alums.

Iron(III) Sulfate Solution (45% Fe2(SO4)3)

A 45% aqueous solution of iron(III) sulfate used in wastewater treatment and etching. Though a solution, it remains under HTS 2833.29.20.00 when chemically defined as iron sulfate concentrate.

Ferrous Sulfate Granules for Agriculture

Granulated ferrous sulfate heptahydrate designed for soil amendment to correct iron deficiencies in crops. Falls under HTS 2833.29.20.00 as a pure iron sulfate, not yet a formulated fertilizer.