Calcium sulfite

CAS 10257-55-3

U.S. production volumes are classified as confidential business information.

Molecular structure of 10257-55-3 — 1 Ca²⁺

US productionCBI

Confidential Business Information. The EPA withholds this volume because publishing it could reveal the reporting company's trade secrets.

Import value, 2024$4M

Top sourceItaly 46%

At least one company claimed its 2023 production or import volume for this chemical as confidential, so EPA withholds it.

Why supply is unknown

Production is reported production, not a complete census of factories. US production volume is confidential. Production reporting year: 2023. Import value and source-country shares describe a shared customs category, not a separate chemical measurement.

Where It Comes From

Customs basis: HS 283220 · basket

EPA reports by year

2023: US production Confidential · Imports Confidential
2019: US production Confidential · Imports Zero

These shares come from HS customs code 283220, which covers 11 tracked chemicals in total. They estimate the category's origin mix, not this chemical specifically.

Source Countries

Country of origin for US imports, from Census customs data (2024).

IT 46%ItalyCN 33%ChinaDE 18%GermanyIN 1%IndiaNZ 1%New Zealand

Denmark
Hong Kong
Japan
Spain

EPA-registered manufacturers (2)

Companies that report making or importing this chemical to the EPA. Registration is US-centric and does not indicate import origin.

Public Service Company Of Colorado

Xcel Energy

Domestic parents -- activity not disclosed (1)

EPA records name a US company for this chemical but do not disclose whether the company made it here or imported it.

Tessenderlo Kerley

Why It Matters

Sectors

Metals & Mining

Downstream UsesNot recorded

FDA Shortage Status

Whether any manufacturer currently reports this drug as in shortage on the FDA Drug Shortages database. "Active Shortage" means at least one presentation has status "current."

No FDA shortage records

Industrial Uses

•Leaching agent in Mining (except Oil and Gas) and support activities (100%)Processing as a reactant

Vendor Pricing

$0.02/gAaron Chemicals LLC

CountryHong Kong

Pack$12.00 / 500 g

Purity90%

Vendors8 available

Prices reflect listed pack sizes. Small research packs run far above bulk rates.

7 more vendors

Vendor	Country	$/g	Pack	Purity
Angene Chemical	China → Hong Kong	$0.03	500 g	90%
A2B Chem LLC	United States	$0.04	500 g	90%
AA BLOCKS	United States	$0.04	500 g	90%
Combi-Blocks, Inc.	United States	$0.25	1 kg	90%
AK Scientific, Inc.	United States	$3.56	25 g	95%
Angene International Limited	United States	$6.88	25 g	95%
Angene	China → Hong Kong	$4266.67	30 mg	90%

Chemical Identity

CAS10257-55-3

PubChem CID10154041

DTXSIDDTXSID10883104

FormulaCaO3S

Mol. Weight120.14 g/mol

SMILES[O-]S(=O)[O-].[Ca+2]

Data Sources

EPA CompTox (DSSTox) · DTXSID10883104Retrieved 2026-04-06
PubChem · compound 10154041Retrieved 2026-04-06
EPA Chemical Data ReportingReporting year: 2023 · Retrieved 2026-10-04
EPA Chemical Data ReportingReporting year: 2023 · Retrieved 2026-10-04
US Census international tradeReporting year: 2024 · Retrieved 2026-10-04

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Brief citations

Calcium sulfite (CAS 10257-55-3) https://chemicalindependence.com/chemical/10257-55-3/ EPA CompTox (DSSTox): DTXSID10883104. Retrieved 2026-04-06. https://comptox.epa.gov/dashboard/chemical/details/DTXSID10883104 PubChem: 10154041. Retrieved 2026-04-06. https://pubchem.ncbi.nlm.nih.gov/compound/10154041 EPA Chemical Data Reporting: 10257-55-3. Reporting year: 2023. https://www.epa.gov/chemical-data-reporting EPA Chemical Data Reporting: CAS 10257-55-3. Reporting year: 2023. https://www.epa.gov/chemical-data-reporting US Census international trade: HS 283220 for CAS 10257-55-3. Reporting year: 2024. https://usatrade.census.gov/