Molekula
Thymol blue
Supplying 4,500+ customers in over 80 countries
ISO 9001:2015 & ISO 14001:2015 certified · Supplying laboratories and industry since 1999 · Listed pack sizes are a starting point — we manufacture, source and repack to the quantity you need
Thymol blue is a pH indicator used in analytical chemistry to detect acidity and alkalinity, particularly in the pH range of 1.2 to 2.8 and 8.0 to 9.6. It is supplied as a dark brownish powder, and in solution it changes from red to yellow (pH 1.2 to 2.8) and from yellow to blue (pH 8.0 to 9.6). CAS: 76-61-9, Molecular Formula: C27H30O5S, Molecular Weight: 466.59 g/mol, Storage: Ambient, Signal Word: Warning.
Molekula supplies Thymol blue in 25 g packs, from £37.08 inc. VAT. It is in stock for same-day dispatch. Every batch ships with a certificate of analysis, and safety data sheets are available in 7 languages. Larger quantities, up to multi-tonne, are quoted on request.
Example image for illustration only. Other packaging and pack sizes are available.
Often bought together
Pricing & pack sizes
In stock — same-day dispatch
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.
-
25 g — £30.90 per pack ex VAT · £37.08 inc. VAT
Need a different quantity or pack?
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 | Dark Brownish Powder |
| Loss on Drying | ≤3% |
| Solubility at 0.1% (95% Ethanol) | Clear solution |
| Wavelength of Max. Absorption | 431 - 436nm |
| Specific Absorbance (E 1%/1cm) | ≥200 |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | Ambient |
| Acidity | Neutral |
Literature values
Published physical properties of the substance, not batch specifications.
| Property | Value |
|---|---|
| Melting Point | 223 °C |
Source: PubChem CID 65565 (PAC Chemical Database)
Identification
| Property | Value |
|---|---|
| SKU | 12900344 |
| CAS Number | 76-61-9 |
| IUPAC Name | 4-[3-(4-hydroxy-2-methyl-5-propan-2-ylphenyl)-1,1-dioxo-2,1lambda6-benzoxathiol-3-yl]-5-methyl-2-propan-2-ylphenol |
| EC Number | 200-973-3 |
| Molecular Formula | C27H30O5S |
| Molecular Weight | 466.59 |
| Exact Mass | 466.1814 |
| SMILES | CC1=CC(=C(C=C1C2(C3=CC=CC=C3S(=O)(=O)O2)C4=CC(=C(C=C4C)O)C(C)C)C(C)C)O |
| InChIKey | PRZSXZWFJHEZBJ-UHFFFAOYSA-N |
| InChI | InChI=1S/C27H30O5S/c1-15(2)19-13-22(17(5)11-24(19)28)27(21-9-7-8-10-26(21)33(30,31)32-27)23-14-20(16(3)4)25(29)12-18(23)6/h7-16,28-29H,1-6H3 |
| PubChem CID | 65565 |
| REACH Code | Y110 |
| TSCA Listed | Yes |
| HTS Code | 2934.99.4400 |
| Tariff Code | 2934999090 |
Safety & GHS
-
Health Hazard
GHS07
Hazard statements
- H302 Harmful if swallowed
Precautionary statements
- P264 Wash thoroughly after handling
- P280 Wear protective gloves/protective clothing/eye protection/face protection
- P301+330 IF SWALLOWED: Rinse mouth. Do NOT induce vomiting
- P308+313 IF exposed or concerned: Get medical advice/attention
Documents
Safety Data Sheets (SDS)
Available in English, English (US), French, German, Italian, Portuguese, Spanish.
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.
Quality certificates
Molekula Group is certified to ISO 9001:2015 (quality) and ISO 14001:2015 (environmental management), audited by a UKAS-accredited body. Both certificates are valid to 17 May 2028.
Synonyms
- Thym
- Thymol Bleu
- Thymol, 6,6'-(3H-2,1-benzoxathiol-3-ylidene)di-, S,S-dioxide
- Thymolblau
- Thymolsulfonephalein
- Thymolsulfonephthalein
- Thymolsulfonphthalein
- Thymolsulfophthalein
- Thymolsulphonphthalein
- Thymosulfonphthalein
Frequently asked questions
What is thymol blue used for?
Thymol blue is primarily used as a pH indicator in analytical chemistry, particularly in the range of pH 1.2 to 2.8 and 8.0 to 9.6.
What is the chemical formula and molecular weight of thymol blue?
The formula is C27H30O5S with a molecular weight of 466.59 g/mol.
How should thymol blue be stored?
Store at ambient temperature, protected from light and moisture.
What grade of thymol blue does Molekula supply?
Molekula supplies thymol blue as a dark brownish powder to the following specification: loss on drying of no more than 3%, a clear solution at 0.1% in 95% ethanol, maximum absorption at 431 to 436 nm, and specific absorbance (E 1%/1cm) of at least 200. Please contact Molekula for details on available grades.
Can Molekula supply thymol blue in bulk quantities?
Yes, Molekula can supply thymol blue in bulk; please contact sales for volume pricing.
What documentation comes with a thymol blue order?
Each order includes a Certificate of Analysis (CoA) and Safety Data Sheet (SDS).
Where can I buy Thymol blue?
Directly from Molekula, which lists Thymol blue in 25 g packs from £37.08 inc. VAT, with a certificate of analysis for every batch. Larger quantities are quoted on request. Molekula's offices: United Kingdom, France, Spain, Germany, Italy, United States and China.
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.