Molekula
Methyl Orange
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
Methyl Orange is a synthetic azo dye primarily used as a pH indicator in laboratories and industrial processes, changing color from red to yellow-orange around pH 3.1–4.4. It is also employed in titrations and as a dye for textiles, paper, and cosmetics. This chemical has a CAS number of 547-58-0, a molecular formula of C14H14N3NaO3S, and a molecular weight of 327.33 g/mol. It should be stored at ambient conditions and handled with caution, as it carries a "Danger" signal word.
Molekula supplies Methyl Orange in 25 g, 100 g and 500 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 5 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.
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25 g — £30.90 per pack ex VAT · £37.08 inc. VAT
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100 g — £45.00 per pack ex VAT · £54.00 inc. VAT
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500 g — £108.80 per pack ex VAT · £130.56 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 | Orange/ yellow powder |
| pH | 3.0 - 4.4 |
| Loss on Drying | ≤ 5.0% |
| Dye Content | ≥ 95.0% |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | Ambient |
| Transport Class | 6.1 |
| Packing Group | III |
| Acidity | Acid |
Identification
| Property | Value |
|---|---|
| SKU | 42196193 |
| CAS Number | 547-58-0 |
| IUPAC Name | sodium 4-[[4-(dimethylamino)phenyl]diazenyl]benzenesulfonate |
| EC Number | 208-925-3 |
| Molecular Formula | C14H14N3NaO3S |
| Molecular Weight | 327.33 |
| Exact Mass | 327.0654 |
| SMILES | CN(C)C1=CC=C(C=C1)N=NC2=CC=C(C=C2)S(=O)(=O)[O-].[Na+] |
| InChIKey | STZCRXQWRGQSJD-UHFFFAOYSA-M |
| InChI | InChI=1S/C14H15N3O3S.Na/c1-17(2)13-7-3-11(4-8-13)15-16-12-5-9-14(10-6-12)21(18,19)20;/h3-10H,1-2H3,(H,18,19,20);/q;+1/p-1 |
| PubChem CID | 23673835 |
| UN Number | UN3143 |
| REACH Code | Y110 |
| TSCA Listed | Yes |
| HTS Code | 29270030 |
| Tariff Code | 2927000090 |
Safety & GHS
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Toxic
GHS06
Hazard statements
- H301 Toxic if swallowed
Precautionary statements
- P280 Wear protective gloves/protective clothing/eye protection/face protection
- P301+310 IF SWALLOWED: Immediately call a POISON CENTER or doctor/physician
- P302+352 IF ON SKIN: Wash with soap and water
- P304+341 IF INHALED: If breathing is difficult, remove victim to fresh air and keep at rest in a position comfortable for breathing
- P305+351+338 IF IN EYES: Rinse with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing
- P331 Do NOT induce vomiting
Documents
Safety Data Sheets (SDS)
Available in English, French, German, Italian, 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
- Acid Orange 52
- C.I. 13025
- C.I. Acid Orange 52
- Eniamethyl Orange
- Gold Orange
- Helianthine
- Helianthine B
- Methyl Orange B
- Orange III
- Tropaeolin D
Frequently asked questions
What is Methyl Orange primarily used for?
Methyl Orange is commonly used as a pH indicator in acid-base titrations, typically changing color from red to yellow-orange around pH 3.1–4.4.
What is the chemical formula and molecular weight of Methyl Orange?
The chemical formula is C₁₄H₁₄N₃NaO₃S, and the molecular weight is 327.33 g/mol.
How should Methyl Orange be stored?
Store Methyl Orange at ambient temperature in a tightly sealed container, away from direct sunlight and moisture.
What grades or purities of Methyl Orange does Molekula supply?
Molekula supplies Methyl Orange as an orange/yellow powder with a dye content of at least 95.0% and a loss on drying of no more than 5.0%, suitable for laboratory and industrial applications requiring consistent performance.
Can Molekula supply Methyl Orange in bulk quantities?
Yes, Molekula can provide Methyl Orange in bulk, with quantities and packaging tailored to your specific requirements.
What documentation comes with an order of Methyl Orange?
Each order includes a Certificate of Analysis (CoA), Material Safety Data Sheet (MSDS), and batch-specific documentation for traceability.
Where can I buy Methyl Orange?
Directly from Molekula, which lists Methyl Orange in 25 g, 100 g and 500 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.
Is Methyl Orange dangerous goods for shipping?
Yes. Methyl Orange ships as dangerous goods: UN3143, class 6.1, packing group III.
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.