1H-Indole-2,3-dione
CAS 91-56-5
This chemical is listed as active in US commerce, but no company reported it to EPA’s survey for 2019 or 2023. Sites may have made or imported less than the threshold amount, or none.
Why supply is unknownProduction is reported production, not a complete census of factories. Import value and source-country shares describe a shared customs category, not a separate chemical measurement.
Where It Comes From
Customs basis: HS 293379 · basket
These shares come from HS customs code 293379, which covers 105 tracked chemicals in total. They estimate the category's origin mix, not this chemical specifically.
- Brazil
- Canada
- Taiwan
- Ukraine
- Portugal
- Netherlands
- South Korea
- Israel
- Czech Republic
- Spain
- Finland
- Hungary
- Malaysia
- Australia
- Austria
- Slovenia
Why It Matters
No EPA sector or FDA product records name a use for this chemical.
Vendor Pricing
Prices reflect listed pack sizes. Small research packs run far above bulk rates.
35 more vendors
| Vendor | Country Supplier country. Where available, shows shipping origin. When the supplier ships from a different country than where they are registered, both are shown. Most suppliers show registration country only. | $/g | Pack | Purity |
|---|---|---|---|---|
| Angene Chemical | China → Hong Kong | $0.05 | 1 kg | 98% |
| A2B Chem LLC | United States | $0.05 | 1 kg | 98% |
| AstaTech, Inc | United States | $0.06 | 500 g | 95% |
| AA BLOCKS | United States | $0.06 | 1 kg | 98% |
| Chemscene | United States | $0.08 | 1 kg | — |
| BLD Pharmatech Co., Limited | United States | $0.08 | 1 kg | 98% |
| BLD Pharmatech GmbH | Germany | $0.08 | 1 kg | 98% |
| BLD Pharmatech Ltd. | China | $0.08 | 1 kg | 98% |
| Ambeed, Inc. | United States | $0.08 | 1 kg | 98% |
| Fluorochem EU | Germany | $0.09 | 500 g | 97% |
| Fluorochem UK | United Kingdom | $0.09 | 1 kg | 97% |
| Apollo Scientific UK | United Kingdom | $0.10 | 25 kg | 98% |
| MedChemExpress MCE | Sweden | $0.24 | 1 kg | 99.93% |
| Combi-Blocks, Inc. | United States | $0.25 | 1 kg | 97% |
| AK Scientific Specialized | United States | $0.25 | 1 kg | 95% |
| Sigma-Aldrich (Rush Stock) | Germany | $0.32 | 500 g | 97% |
| Sigma-Aldrich | Germany | $0.32 | 500 g | 97% |
| AK Scientific, Inc. | United States | $0.34 | 1 kg | 98% |
| Angene International Limited | United States | $0.56 | 100 g | 98% |
| Aldlab | United States | $1.38 | 5 g | 95% |
| MedKoo Biosciences, Inc | United States | $10.00 | 25 g | 98% |
| Interbioscreen | Hong Kong | $24.00 | 10 g | 95% |
| ChemDiv, Inc. | United States | $25.00 | 25 g | 90% |
| Molnova | China | $52.00 | 500 mg | 99% |
| TargetMol Chemicals | China → United States | $58.00 | 500 mg | 99.08% |
| Labotest KG | Germany | $217.80 | 5000 mg | 90% |
| Apexbio Technology LLC | United States | $286.00 | 500 mg | 99.84% |
| HTS Biochemie Innovationen | Germany | $350.00 | 1 g | 95% |
| ChemBridge Corporation | Kazakhstan | $1860.00 | 100 mg | 90% |
| Otava, Ltd. | Ukraine | $2280.00 | 50 mg | 95% |
| Otava, Ltd. (2 weeks) | Ukraine | $2724.00 | 50 mg | 90% |
| Key Organics Ltd. | United Kingdom | $2740.00 | 50 mg | 98% |
| Princeton BioMolecular Research (SC) | United States | $2900.00 | 100 mg | 90% |
| Vitas M Chemical Limited | Hong Kong | $3170.00 | 100 mg | 90% |
| Angene | China → Hong Kong | $4266.67 | 30 mg | 98% |
Chemical Identity
Data Sources
- EPA TSCA InventoryRetrieved 2026-10-04
- US Census international tradeReporting year: 2024 · Retrieved 2026-10-04
Brief citations
1H-Indole-2,3-dione (CAS 91-56-5) https://chemicalindependence.com/chemical/91-56-5/ EPA TSCA Inventory: CAS 91-56-5. Retrieved 2026-10-04. https://www.epa.gov/tsca-inventory US Census international trade: HS 293379 for CAS 91-56-5. Reporting year: 2024. https://usatrade.census.gov/