C.I. Acid Red 249

CAS 6416-66-6

2,7-Naphthalenedisulfonic acid, 3-[2-(5-chloro-2-phenoxyphenyl)diazenyl]-4-hydroxy-5-[[(4-methylphenyl)sulfonyl]amino]-, sodium salt (1:2)

EPA and Census publish no US supply data for this chemical.

Molecular structure of 6416-66-6
2 Na⁺
US productionNot reported
Top sourceNo public record

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

Where It Comes From

EPA and Census publish no US supply data for this chemical.

Why It Matters

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

Chemical Identity

CAS6416-66-6
PubChem CIDNot recorded
DTXSIDDTXSID80889431
FormulaC29H20ClN3Na2O10S3
Mol. Weight748.1 g/mol
SMILES[Na+].[Na+].CC1=CC=C(C=C1)S(=O)(=O)NC1=C2C(O)=C(N=NC3=C(OC4=CC=CC=C4)C=CC(Cl)=C3)C(=CC2=CC(=C1)S([O-])(=O)=O)S([O-])(=O)=O

Data Sources

Brief citations

C.I. Acid Red 249 (CAS 6416-66-6) https://chemicalindependence.com/chemical/6416-66-6/ EPA TSCA Inventory: CAS 6416-66-6. Retrieved 2026-10-04. https://www.epa.gov/tsca-inventory