Molekula
Phenol Red
Supplying 4,500+ customers in over 80 countries
ISO 9001:2015 & ISO 14001:2015 certified · Supplying laboratories and industry since 2000 · Listed pack sizes are a starting point — we manufacture, source and repack to the quantity you need
Phenol Red is a synthetic pH indicator dye used in biological and chemical applications to detect pH changes in solutions, particularly in the range of 6.8–8.2, turning yellow to red. It is also employed in cell culture media and as a component in some diagnostic tests. This chemical has a CAS number of 143-74-8, a molecular formula of C19H14O5S, and a molecular weight of 354.38 g/mol. It should be stored at ambient temperatures, and it carries a signal word of *Warning* for safety. Molekula supplies Phenol Red from research to bulk quantities with full documentation and ISO 9001:2015 traceability.
Example image for illustration only. Other packaging and pack sizes are available.
Often bought together
Pricing & pack sizes
These pack sizes aren't a limit. Molekula manufactures, sources and repacks to order — if you need 500 kg and only see 1 kg listed, . We quote from grams to multi-tonne.
Need a different size? Add the nearest pack and change the size in your basket — we price it at the same rate per unit.
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100 g — £77.70 per pack ex VAT · £93.24 inc. VAT
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Tell us how much you need and when — drums, IBCs, sacks or a one-off bulk lot. We'll manufacture or source it and come back with a price.
Prices exclude VAT/sales tax and shipping.
Specifications
| Property | Value |
|---|---|
| Appearance | Red powder |
| Loss on Drying | ≤5% (110℃) |
| Transition Range | Yellow - Red (pH 6.5 - 8.2) |
| Solubility in water | Slightly soluble |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | Ambient |
| Acidity | Neutral |
Identification
| Property | Value |
|---|---|
| SKU | 30469104 |
| CAS Number | 143-74-8 |
| IUPAC Name | 4-[3-(4-hydroxyphenyl)-1,1-dioxo-2,1lambda6-benzoxathiol-3-yl]phenol |
| EC Number | 205-609-7 |
| Molecular Formula | C19H14O5S |
| Molecular Weight | 354.38 |
| Exact Mass | 354.0562 |
| SMILES | C1=CC=C2C(=C1)C(OS2(=O)=O)(C3=CC=C(C=C3)O)C4=CC=C(C=C4)O |
| InChIKey | BELBBZDIHDAJOR-UHFFFAOYSA-N |
| InChI | InChI=1S/C19H14O5S/c20-15-9-5-13(6-10-15)19(14-7-11-16(21)12-8-14)17-3-1-2-4-18(17)25(22,23)24-19/h1-12,20-21H |
| PubChem CID | 4766 |
| REACH Code | Y113 |
| TSCA Listed | Yes |
| HTS Code | 2907.29.9000 |
| Tariff Code | 2907290090 |
Safety & GHS
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Health Hazard
GHS07
Hazard statements
- H315 Causes skin irritation
- H319 Causes serious eye irritation
- H335 May cause respiratory irritation
Precautionary statements
- P261 Avoid breathing dust/fume/gas/mist/vapours/spray
- P264 Wash thoroughly after handling
- P280 Wear protective gloves/protective clothing/eye protection/face protection
- P302+P352 IF ON SKIN: Wash with soap and water
- P304+P340 IF INHALED: Remove victim to fresh air and keep at rest in a position comfortable for breathing
- P305+P351+P338 IF IN EYES: Rinse continuously with water for several minutes. Remove contact lenses if present and easy to do, continue rinsing
Documents
Safety Data Sheets (SDS)
Available in English, German, Spanish, French, Italian, Portuguese, Arabic, Dutch.
Certificate of Analysis (CoA) by batch
Enter a lot or batch number to retrieve the CoA for that specific batch. We can generate one from spec data if no PDF is on file.
Synonyms
- 2-(Bis(4-hydroxyphenyl)methyliumyl)benzenesulfonate
- 3,3-bis(4-hydroxyphenyl)-3H-2,1??-benzoxathiole-1,1-dione
- Fenolipuna
- Phenol, 4,4'-(3H-2,1-benzoxathiol-3-ylidene)bis-, (S,S-dioxide)
- phenolsulfonphthalein
- Phenolsulphonphthalein
- PSP (indicator)
- Sulfonphthal
- Sulphental
- Sulphonthal
Frequently asked questions
What is Phenol Red primarily used for?
Phenol Red is commonly used as a pH indicator in biological buffers, cell culture media, and biochemical assays, with a transition range of pH 6.8–8.2 (yellow to red).
What is the molecular formula and molecular weight of Phenol Red?
The molecular formula is **C₁₉H₁₄O₅S** and the molecular weight is **354.38 g/mol**.
How should Phenol Red be stored?
Store Phenol Red at **ambient temperature** in a tightly sealed container, protected from light and moisture.
What grades of Phenol Red does Molekula supply?
Molekula supplies **analytical grade** Phenol Red, suitable for laboratory and research applications.
Can Molekula supply Phenol Red in bulk quantities?
Yes, Molekula can provide Phenol Red in bulk, with quantities and packaging tailored to your requirements.
What documentation comes with an order of Phenol Red?
Each order includes a **Certificate of Analysis (CoA)**, Material Safety Data Sheet (MSDS), and batch-specific documentation for traceability.
Ready to order or need a custom pack?
Tell us the product, grade, and quantity — Molekula usually responds within one working day with pricing and lead time.