ACID BLUE 9 AMMONIUM SALT- ▸ Textile dyeing: red colorant for wool, silk and nylon
- ▸ Paper and soap: water-soluble red for paper and soap coloring
- ▸ Wood staining: applied as a red wood stain
- ▸ Biological staining: used as a biological stain and indicator
A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.
Request SDS →FD&C Red No. 4 (Ponceau SX, CAS 2650-18-2) is a water-soluble monoazo acid dye supplied as a red colorant. Established uses include dyeing wool, silk, nylon, paper and soap, wood staining, and service as a biological stain and indicator.
Regulatory & registration requirements
- TSCA (US):
- REACH (EU):
- EC number: 224-909-9
Source: EPA TSCA Inventory (July 2025 release) · ECHA CHEM — retrieved 2026-07-12
Solutions Using This Product
Process-solution guides on this site that specify this chemistry:
Frequently Asked Questions
What is FD&C Red No. 4?
FD&C Red No. 4 (Ponceau SX, CAS 2650-18-2) is a water-soluble monoazo acid dye supplied as a red colorant. Established uses include dyeing wool, silk, nylon, paper and soap, wood staining, and service as a biological stain and indicator.
How is FD&C Red No. 4 made?
It is a synthetic monoazo dye (Ponceau SX) produced by chemical synthesis, not derived from animal or insect sources such as carmine. The CAS number is 2650-18-2.
What is FD&C Red No. 4 used for?
It is used as a water-soluble red colorant for textiles (wool, silk, nylon), paper, and soap, as a red wood stain, and as a biological stain and indicator.
What does kosher certification mean for this dye?
Kosher means the material is produced under kosher certification. Request the current certificate and CoA with your order to confirm the certifying authority and the specifications it covers.
What is the cost of bulk FD&C Red No. 4?
Bulk pricing depends on grade, volume, packaging, and delivery location. RawSource supplies industrial quantities — request a quote with your volume, kosher certification, and CoA/SDS requirements for delivered pricing.
What is the REACH and TSCA regulatory status of FD&C Red No. 4 (Ponceau SX, C.I. 14700)?
FD&C Red No. 4 (Ponceau SX, C.I. 14700) (CAS 4548-53-2) is subject to U.S. TSCA Inventory requirements; supplying it into the EU requires valid REACH registration ((EC) No 1907/2006). RawSource cannot verify a third-party supplier's registrations — buyers should require documented TSCA and REACH compliance for their jurisdiction and volume (EC 224-909-9).