ASD-641
Ponceau 4R (E124) – Food Grade Red Colour Powder | CI 16255, CAS 2611-82-7 | ASD-641
$25.00
AUD ex GST
Biological Stains & Dyes · C.I. 16255
Ponceau 4R (E 124)
Water-soluble red azo dye for E 124 colour reference work, spectrophotometry, analytical method development and teaching.
Cat. No. ASD-641CAS 2611-82-7Dye content ≥ 80 %λmax ≈ 505 nmFood-grade E 124
Also known as: Acid Red 18, Cochineal Red A, New Coccine, CI Food Red 7. Not the same dye as Ponceau S (protein stain) or Ponceau SX.
At a Glance
FormulaC₂₀H₁₁N₂Na₃O₁₀S₃
Mol. weight604.47 g/mol
AppearanceBright red powder
1 % solutionStrawberry red
Solubility (water)Soluble
Batch dye content85.03 %
Overview
Ponceau 4R is the trisodium salt of a sulfonated naphthylazo-naphthol dye. Its three sulfonate groups make it water-soluble and strongly anionic. The powder is bright red, and dilute solutions are strawberry red with an absorption maximum near 505 nm.
In the laboratory, Ponceau 4R is used as the reference colour for E 124 analysis, as an absorbance standard, and as a model azo dye in chromatography, sensing and decolourisation research.
For laboratory, research, education and quality-control use. Not intended for human or veterinary therapeutic use, diagnosis, or direct consumption. Food-grade (E 124) material. For food-industry supply, contact Ausamics for suitability and regulatory documentation.
Colour at a Glance
Powder is bright red. Solution is strawberry red. Absorbance rises in direct proportion to concentration at 505 nm.
dilute solutionpowder
Key Applications
Food Colour QCReference material for E 124 identification, HPLC and spectrophotometric assay of red food colours.
SpectrophotometryStable red dye (λmax ≈ 505 nm) for absorbance calibration and Beer–Lambert teaching.
Analytical Method DevelopmentModel azo dye for chromatography, electrochemical sensing and dye-removal studies.
Environmental ResearchTest compound in adsorption, photocatalysis and wastewater decolourisation experiments.
EducationIntense, water-soluble red for chromatography, colour-mixing and diffusion practicals.
Formulation DevelopmentRed colourant for prototype buffers, gels and visual tracer solutions in research.
Advantages & Considerations
Advantages
- Pure dye content ≥ 80 % (current batch 85.03 %)
- Meets the E 124 purity limits on the batch certificate
- Very low heavy metals: lead and arsenic below 1 ppm
- Readily water-soluble; no heating needed
Considerations
- Not a protein stain: use Ponceau S for western blot membranes
- Not permitted as a food colour in the United States
- Fades under strong oxidants, reducing agents and strong light
- Avoid creating dust when weighing
Specification Summary
| Parameter | Specification |
|---|---|
| Pure dye content (E 1 %, 1 cm at 505 nm) | Min. 80.0 % |
| Appearance | Bright red powder |
| Hue of 1 % solution | Strawberry red |
| Loss on drying at 135 °C (as sodium salts) | Max. 20.0 % |
| Moisture at 110 °C | Max. 2.0 % |
| Water-insoluble matter | Max. 0.20 % |
| Subsidiary colouring matters | Max. 1.0 % |
| Organic compounds other than colouring matters | Max. 0.5 % |
| Unsulfonated primary aromatic amines (as aniline) | Max. 0.01 % |
| Ether-extractable matter | Max. 0.2 % |
| Arsenic (As) | Max. 1 ppm |
| Lead (Pb) | Max. 1 ppm |
| Mercury (Hg) | Max. 0.05 ppm |
| Cadmium (Cd) | Max. 0.1 ppm |
| Chromium (Cr) | Max. 2 ppm |
| Copper (Cu) | Max. 30 ppm |
| Zinc (Zn) | Max. 50 ppm |
| Heavy metals (as Pb) | Max. 5 ppm |
Frequently Asked Questions
Is Ponceau 4R the same as Ponceau S?
No. Ponceau S (C.I. 27195) is the red dye used to stain proteins on western blot membranes. Ponceau 4R (C.I. 16255) is a different azo dye, mainly used as the food colour E 124 and as an analytical reference. Do not substitute one for the other.
Is Ponceau 4R the same as Ponceau SX or FD&C Red No. 4?
No. Ponceau SX is C.I. 14700 and is sold in the US as FD&C Red No. 4. Ponceau 4R is C.I. 16255. The two dyes have different structures and regulatory status.
Is Ponceau 4R permitted as a food colour?
It is permitted in the EU as E 124 and is listed in the Australia New Zealand Food Standards Code as colour 124. It is not permitted as a food colour in the United States.
How do I make a stock solution?
Dissolve 1.0 g in about 80 mL of purified water, stir until clear and make up to 100 mL to give a 1 % w/v solution. Store away from light.
What wavelength should I use for absorbance measurements?
Ponceau 4R absorbs most strongly at about 505 nm in water. Use this wavelength for calibration curves and dye-content checks.
Technical Specifications
| Catalogue No. | ASD-641 |
| C.I. number | 16255 |
| CAS / EC | 2611-82-7 / 220-036-2 |
| E number | E 124 |
| Formula | C₂₀H₁₁N₂Na₃O₁₀S₃ |
| Mol. weight | 604.47 g/mol |
| Dye content | Min. 80 % (E 1 %, 505 nm) |
| λmax | ≈ 505 nm (water) |
| Storage | 15–25 °C, dry, dark, tightly closed |
| Shelf life | 36 months from manufacture |
| Documents | TDS, SDS; batch COA on request |
Applications
- E 124 reference and QC
- Spectrophotometry standard
- HPLC method development
- Dye-removal research
- Teaching laboratories
Stock Solution (1 % w/v)
- Weigh 1.0 g of Ponceau 4R.
- Add to about 80 mL of purified water.
- Stir until fully dissolved; no heating is needed.
- Make up to 100 mL with purified water.
- Store in a closed bottle at room temperature, away from light.
Storage & Stability
Store at 15–25 °C in a dry place, tightly closed and protected from sunlight, heat and moisture. Shelf life is 36 months from the date of manufacture under these conditions.
Technical Data Sheet — Ponceau 4R
TDS-ASD-641 · Rev 1.0 · November 20261. Identification
| Chemical name | Trisodium (8Z)-7-oxo-8-[(4-sulfonatonaphthalen-1-yl)hydrazinylidene]naphthalene-1,3-disulfonate |
| Synonyms | Ponceau 4R; Acid Red 18; Cochineal Red A; New Coccine; CI Food Red 7; Brilliant Scarlet 3R |
| C.I. number | 16255 |
| E number | E 124 |
| CAS number | 2611-82-7 |
| EC number | 220-036-2 |
| Molecular formula | C₂₀H₁₁N₂Na₃O₁₀S₃ |
| Molecular weight | 604.47 g/mol |
| Dye class | Monoazo, anionic (acid) dye |
2. Intended Use
E 124 reference colour, spectrophotometric standard, model azo dye for analytical and environmental research, and teaching reagent. For laboratory, research, education and quality-control use. Not intended for human or veterinary therapeutic use, diagnosis, or direct consumption.
3. Mode of Action
The three sulfonate groups make Ponceau 4R strongly anionic and water-soluble. Its naphthylazo-naphthol chromophore absorbs blue-green light at about 505 nm, which gives the red colour.
4. Physical & Chemical Properties
| Appearance | Bright red powder |
| Colour of 1 % aqueous solution | Strawberry red |
| Absorption maximum (λmax) | approx. 505 nm in water |
| Solubility | Soluble in water; sparingly soluble in ethanol |
| Moisture at 110 °C | Max. 2.0 % |
| Stability | Good stability in normal laboratory conditions; protect from sunlight, heat and moisture |
5. Specifications
| Parameter | Specification |
|---|---|
| Pure dye content (E 1 %, 1 cm at 505 nm) | Min. 80.0 % |
| Appearance | Bright red powder |
| Hue of 1 % solution | Strawberry red |
| Loss on drying at 135 °C (as sodium salts) | Max. 20.0 % |
| Moisture at 110 °C | Max. 2.0 % |
| Water-insoluble matter | Max. 0.20 % |
| Subsidiary colouring matters | Max. 1.0 % |
| Organic compounds other than colouring matters | Max. 0.5 % |
| Unsulfonated primary aromatic amines (as aniline) | Max. 0.01 % |
| Ether-extractable matter | Max. 0.2 % |
| Arsenic (As) | Max. 1 ppm |
| Lead (Pb) | Max. 1 ppm |
| Mercury (Hg) | Max. 0.05 ppm |
| Cadmium (Cd) | Max. 0.1 ppm |
| Chromium (Cr) | Max. 2 ppm |
| Copper (Cu) | Max. 30 ppm |
| Zinc (Zn) | Max. 50 ppm |
| Heavy metals (as Pb) | Max. 5 ppm |
6. Solution Preparation
Stock solution (1 % w/v): dissolve 1.0 g in about 80 mL purified water and make up to 100 mL. Dilute for use according to your method.
7. Storage & Shelf Life
15–25 °C, dry, tightly closed, protected from sunlight, heat and moisture. Shelf life 36 months from manufacture.
8. References
- Commission Regulation (EU) No 231/2012, Annex: E 124 Ponceau 4R, Cochineal Red A. Specifications for food additives.
- FAO/WHO JECFA (2011). Ponceau 4R: specifications and toxicological evaluation (74th meeting). ADI 0–4 mg/kg body weight.
- EFSA ANS Panel (2009). Scientific Opinion on the re-evaluation of Ponceau 4R (E 124) as a food additive. EFSA Journal 7(11):1328.
- Regulation (EC) No 1333/2008 on food additives, Annex V: additional labelling for foods containing E 102, E 104, E 110, E 122, E 124 and E 129.
- Horobin R.W., Kiernan J.A. (eds) (2002). Conn's Biological Stains, 10th ed. BIOS Scientific Publishers, Oxford.
Safety Data Summary — Ponceau 4R
SDS-ASD-641 · Rev 1.0 · November 2026 · Full 16-section SDS available on requestHazard Classification
Not classified as hazardous according to the criteria of the GHS (Rev. 7) as adopted under the Australian Work Health and Safety Regulations. No hazard pictogram or signal word is required.
Handling & Protection
- Avoid creating and breathing dust. Use with adequate ventilation.
- Wear nitrile gloves, laboratory coat and safety glasses.
- The dye stains skin and surfaces; clean spills promptly with water.
First Aid
- Inhalation: Move to fresh air.
- Skin: Wash with soap and water.
- Eyes: Rinse with water for several minutes. Seek medical advice if irritation persists.
- Ingestion: Rinse mouth. Seek medical advice if you feel unwell.
Poisons Information Centre (Australia): 13 11 26 · Emergency: 000
Storage & Disposal
Store at 15–25 °C, dry, tightly closed and protected from light. Dispose of according to local regulations.
Transport
Not regulated as dangerous goods for road (ADG), sea (IMDG) or air (IATA) transport.
Quality & Certificate of Analysis
ASD-641 · Batch-specific COA available on requestEach batch is supplied with traceable manufacturer test data. A batch-specific Certificate of Analysis is available on request. Please quote the batch number printed on the label.
Typical Batch Results
| Test | Specification | Result |
|---|---|---|
| Pure dye content (E 1 %, 1 cm at 505 nm) | Min. 80.0 % | 85.03 % |
| Appearance | Bright red powder | Bright red powder |
| Hue of 1 % solution | Strawberry red | Strawberry red |
| Loss on drying at 135 °C (as sodium salts) | Max. 20.0 % | 12.99 % |
| Moisture at 110 °C | Max. 2.0 % | 0.88 % |
| Water-insoluble matter | Max. 0.20 % | 0.08 % |
| Subsidiary colouring matters | Max. 1.0 % | 0.45 % |
| Organic compounds other than colouring matters | Max. 0.5 % | 0.35 % |
| Unsulfonated primary aromatic amines (as aniline) | Max. 0.01 % | < 0.01 % |
| Ether-extractable matter | Max. 0.2 % | 0.08 % |
| Arsenic (As) | Max. 1 ppm | < 1 ppm |
| Lead (Pb) | Max. 1 ppm | < 1 ppm |
| Mercury (Hg) | Max. 0.05 ppm | 0.005 ppm |
| Cadmium (Cd) | Max. 0.1 ppm | 0.04 ppm |
| Chromium (Cr) | Max. 2 ppm | < 1 ppm |
| Copper (Cu) | Max. 30 ppm | 20 ppm |
| Zinc (Zn) | Max. 50 ppm | 30 ppm |
| Heavy metals (as Pb) | Max. 5 ppm | < 5 ppm |
Results as reported on the manufacturer's certificate of analysis dated 19/10/2026.