Flag of the United StatesAmerican Chemical Independence

Guanine

CAS 73-40-5

6H-Purin-6-one, 2-amino-1,9-dihydro-

Molecular structure of 73-40-5
US productionNot reported
Import value, 2024$7.6B
Top sourceIreland 61%

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 unknown

Production 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 293359 · basket

These shares come from HS customs code 293359, which covers 295 tracked chemicals in total. They estimate the category's origin mix, not this chemical specifically.

Source Countries
IE 61%IrelandCH 30%SwitzerlandGB 2%United KingdomCN 2%ChinaIN 1%India

Why It Matters

No EPA sector or FDA product records name a use for this chemical.

Chemical Identity

CAS73-40-5
PubChem CIDNot recorded
DTXSIDDTXSID9052476
FormulaC5H5N5O
Mol. Weight151.129 g/mol
SMILESNC1=NC2=C(N=CN2)C(=O)N1

Data Sources

← Back to Dashboard

Brief citations

Guanine (CAS 73-40-5) https://chemicalindependence.com/chemical/73-40-5/ EPA TSCA Inventory: CAS 73-40-5. Retrieved 2026-10-04. https://www.epa.gov/tsca-inventory US Census international trade: HS 293359 for CAS 73-40-5. Reporting year: 2024. https://usatrade.census.gov/