Molekula
4-Hydroxybenzoic acid
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
4-Hydroxybenzoic acid is an aromatic carboxylic acid widely used as a precursor in the synthesis of pharmaceuticals, preservatives (e.g., parabens), and agrochemicals. It serves as a key intermediate in organic chemistry for producing esters, dyes, and UV absorbers. This white crystalline solid has a CAS number of 99-96-7, a molecular formula of HOC6H4CO2H, and a molecular weight of 138.12 g/mol. Store at ambient conditions, but handle with caution—it carries a **Danger** signal word due to potential health risks. Molekula supplies 4-hydroxybenzoic acid 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.
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 — £26.40 per pack ex VAT · £31.68 inc. VAT
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500 g — £59.20 per pack ex VAT · £71.04 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 | White crystalline powder |
| Melting Point | 214 - 217°C |
| Heavy metals | ≤10ppm |
| Identification | Conforms to reference |
| Loss on Drying | ≤0.5% |
| Solubility | Clear and Transparent |
| Residue on Ignition | ≤0.5% |
| Purity (dry basis) | ≥ 99% |
| Sulphates (SO4)(2-) | ≤0.05% |
| Chlorine (Cl) | ≤0.02% |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | Ambient |
| Flash Point | 199 °C |
| Acidity | Acid |
Literature values
Published physical properties of the substance, not batch specifications.
| Property | Value |
|---|---|
| Melting Point | 214.5 °C |
| Boiling Point | 334 to 335 °C at 760 mmHg |
| Density | 1.46 g/cm³ at 25 °C |
| Water Solubility | 5 g/L at 25 °C |
| Solubility (other solvents) | Slightly soluble in water; soluble in organic solvents |
| Vapour Pressure | 1.9 × 10⁻⁷ mmHg at 25 °C (Extrapolated) |
| pKa | pKa = 4.54 |
| log P (octanol/water) | 1.58 |
Source: PubChem CID 135 (HSDB, Human Metabolome Database (HMDB), Joint FAO/WHO Expert Committee on Food Additives (JECFA))
Identification
| Property | Value |
|---|---|
| SKU | 34099106 |
| CAS Number | 99-96-7 |
| IUPAC Name | 4-hydroxybenzoic acid |
| EC Number | 202-804-9 |
| Molecular Formula | HOC6H4CO2H |
| Molecular Weight | 138.12 |
| Exact Mass | 138.0317 |
| SMILES | C1=CC(=CC=C1C(=O)O)O |
| InChIKey | FJKROLUGYXJWQN-UHFFFAOYSA-N |
| InChI | InChI=1S/C7H6O3/c8-6-3-1-5(2-4-6)7(9)10/h1-4,8H,(H,9,10) |
| PubChem CID | 135 |
| REACH Code | Y110 |
| TSCA Listed | Yes |
| HTS Code | 29182965 |
| Tariff Code | 2918290090 |
Safety & GHS
-
Corrosive
GHS05
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Health Hazard
GHS07
Hazard statements
- H318 Causes serious eye damage
- H335 May cause respiratory irritation
Precautionary statements
- P261 Avoid breathing dust/fume/gas/mist/vapours/spray
- P280 Wear protective gloves/protective clothing/eye protection/face protection
- P305+351+338 IF IN EYES: Rinse with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing
- P308+313 IF exposed or concerned: Get medical advice/attention
- P310 Immediately call a POISON CENTER or doctor/physician
Documents
Safety Data Sheets (SDS)
Available in English, French, German, Italian, Russian, 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.
Synonyms
- 4-Carboxyphenol
- 4-Hydroxybenzoate
- Benzoic acid, 4-hydroxy-
- Benzoic acid, p-hydroxy-
- FEMA NO. 3986
- p-carboxyphenol
- p-Hydroxybenzoic acid
- p-Oxybenzoesaure
- p-Salicylic acid
- para-Hydroxybenzoic acid
Frequently asked questions
What is 4-Hydroxybenzoic acid commonly used for?
4-Hydroxybenzoic acid is primarily used as a precursor in the synthesis of parabens (preservatives), pharmaceuticals, and as a monomer in polymer production.
What is the chemical formula and molecular weight of 4-Hydroxybenzoic acid?
The chemical formula is **HOC₆H₄CO₂H** and the molecular weight is **138.12 g/mol**.
How should 4-Hydroxybenzoic acid be stored?
Store at **ambient temperature** in a cool, dry place, away from incompatible substances and moisture.
What grades of 4-Hydroxybenzoic acid does Molekula supply?
Molekula supplies **pharmaceutical (USP/EP), food-grade, and technical-grade** 4-Hydroxybenzoic acid, depending on application requirements.
Can Molekula supply 4-Hydroxybenzoic acid in bulk quantities?
Yes, Molekula can supply **bulk quantities** (from kilograms to metric tons) of 4-Hydroxybenzoic acid, with flexible packaging options.
What documentation comes with an order of 4-Hydroxybenzoic acid?
Each order includes a **Certificate of Analysis (CoA), Safety Data Sheet (SDS), and batch-specific documentation** for traceability and compliance.
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.