Acetic Acid CAS 64-19-7
Chelora Chemicals supplies glacial acetic acid to VAM, PTA, acetate ester, textile and food-grade users worldwide. Because glacial acetic acid freezes at 16 °C, every consignment leaves with a batch-specific COA covering purity, water, freezing point and iron, the current SDS and full dangerous-goods documentation.
Also known as: Glacial acetic acid · Ethanoic acid · Methanecarboxylic acid · GAA · AcOH
Request a quotation
Price, lead time and a sample COA for Acetic Acid, usually within one working day. We ship worldwide.
Request a Quote Email the DeskDocumentation
- Batch-specific COA (purity, water, freezing point, iron)
- Safety Data Sheet (SDS)
- Transport and dangerous-goods documents
- Third-party inspection on request
- Certificate of origin
What is Acetic Acid?
Acetic acid is the simplest carboxylic acid with a methyl group, C₂H₄O₂. Glacial acetic acid is the near-anhydrous form, a clear liquid with a sharp vinegar odour that freezes to ice-like crystals at 16.35 °C.
Nearly all production comes from methanol carbonylation with carbon monoxide over rhodium or iridium catalysts, a route that displaced older ethylene and butane oxidation processes on cost.
The main outlets are vinyl acetate monomer, purified terephthalic acid, acetic anhydride and acetate esters. Food, pharmaceutical and textile applications take smaller but higher-specification volumes.
Why Acetic Acid specifically
- A versatile acid. Esterifies, acetylates and acts as a reaction solvent across a wide range of chemistry.
- The VAM route. Reaction with ethylene and oxygen gives vinyl acetate monomer for adhesives and films.
- The PTA solvent. Acetic acid is the reaction medium for para-xylene oxidation, and losses there are a major cost item.
- Food and pharmaceutical acceptance. Approved as a food acidulant, with specific grades for that use.
How Acetic Acid is Manufactured
Acetic acid is made almost entirely by carbonylating methanol, with a small share from fermentation for food use.
- Methanol and CO feed. Grade AA methanol reacts with carbon monoxide from reforming or gasification.
- Rhodium or iridium carbonylation. The Monsanto and Cativa processes run at moderate pressure with an iodide promoter, giving very high selectivity.
- Flash and separation. The reaction mixture is flashed to recover catalyst, which is returned to the reactor.
- Dehydration and purification. Water, iodides and heavy ends are removed in a distillation train to reach glacial quality.
- Iodide removal. Guard beds remove residual iodide, which is critical because iodide poisons downstream catalysts.
- Fermentation route. Food vinegar and some food-grade acid are produced by oxidative fermentation of ethanol instead.
Typical Commercial Specification
Figures below are representative of commercial glacial acetic acid. Food and pharmaceutical grades carry additional limits — tell us the use and we will send the matching sheet.
| Parameter | Typical Value |
|---|---|
| Appearance | Clear colourless liquid, free of suspended matter |
| Acetic acid purity | 99.85% min by weight |
| Water content | 0.15% max |
| Freezing point | 16.35 °C min — the purity indicator |
| Formic acid | To grade, typically 0.05% max |
| Acetaldehyde | To grade, typically 0.05% max |
| Iron | To grade, typically 1 ppm max |
| Iodide | To grade, typically 10 ppb max |
| Permanganate time | To grade, typically 120 minutes min |
| Colour (Pt-Co) | 10 max |
| Non-volatile residue | To grade, typically 50 ppm max |
Physical & Chemical Properties
| Property | Value |
|---|---|
| Chemical formula | C₂H₄O₂ (CH₃COOH) |
| Molecular weight | 60.05 g/mol |
| Appearance | Clear colourless liquid, sharp vinegar odour |
| Boiling point | 118 °C |
| Melting point | 16.6 °C |
| Flash point | About 39 °C (closed cup) |
| Density | 1.049 g/cm³ at 20 °C |
| Vapour pressure | About 1.5 kPa at 20 °C |
| Vapour density (relative to air) | 2.1, heavier than air |
| Flammable limits in air | About 4 to 17% by volume |
| Autoignition temperature | About 463 °C |
| Solubility in water | Completely miscible |
| pKa | 4.76 |
| Incompatibilities | Strong oxidisers, bases, carbonates, chromic acid, permanganates, many metals |
Behaviour in the process
Acetic acid is corrosive and freezes near ambient, and both facts drive its handling:
- Freezes at 16.6 °C. Glacial acetic acid solidifies in cool weather, so heated or traced storage is standard in most climates.
- Expands on freezing. Like water, it expands when it solidifies, which can rupture full drums and lines.
- Corrosive to many metals. Attacks carbon steel, aluminium and galvanised surfaces. Stainless 316 or lined equipment is required.
- Dilution increases corrosivity. Dilute acetic acid is more aggressive to stainless steel than the glacial form, which surprises people.
Acetic Acid Grades and Alternatives
Acetic acid is bought by grade, and the grade is defined by the trace impurities the downstream process cannot tolerate.
| Material | Origin / type | When it is the right choice |
|---|---|---|
| Glacial acetic acid 99.85% | Standard commercial grade | VAM, PTA, esters and general chemical use |
| Food-grade acetic acid | Meets FCC and food additive specifications | Food acidulant, vinegar and preservative use |
| Pharmaceutical grade | USP or BP compliant | Pharmaceutical synthesis and formulation |
| Acetic anhydride | The anhydride, CAS 108-24-7 | Acetylation where water must not be released; subject to precursor controls |
| Dilute acetic acid | Typically 30 to 80% | Textile, cleaning and food applications where glacial handling is impractical |
Stated plainly: for acetylation chemistry, acetic anhydride is the stronger reagent but carries precursor controls. For everything else the grade question is about iodide, iron and permanganate time rather than about headline purity.
Industries We Supply Acetic Acid To
Acetic acid reaches polymers, fibres, textiles, food and pharmaceuticals, with the specification tightening as it goes.
Where Acetic Acid is Used
VAM and PTA together take more than half of global acetic acid. Esters, acetic anhydride and food use account for most of the rest.
In VAM manufacture
Acetic acid, ethylene and oxygen react over a supported palladium-gold catalyst to give vinyl acetate monomer. Iodide is the critical contaminant: traces carried over from the carbonylation catalyst poison the palladium, which is why VAM producers specify iodide in parts per billion and run guard beds regardless.
In PTA manufacture
Acetic acid is the solvent for the cobalt-manganese-bromide catalysed oxidation of para-xylene. Some acid is burned to carbon oxides in the reaction, and that solvent loss is one of the largest variable costs in a PTA plant, which is why acid quality and recovery efficiency are watched closely.
Need a specific grade, purity and packing format?
Tell us the grade, the iodide and iron limits your downstream catalyst needs, the packing format you can receive and the annual quantity. We will come back with a price, a lead time, a sample COA and the full documentation set.
Quality Control & Testing
Every lot is released against a batch-specific Certificate of Analysis, with iodide and iron reported alongside purity because both are decisive for downstream catalysts.
- Acetic acid purity and water — by gas chromatography and Karl Fischer titration.
- Freezing point — the classic confirmation of glacial quality.
- Iodide — reported in ppb because it poisons palladium and oxidation catalysts.
- Iron and heavy metals — measured because they catalyse degradation and discolour products.
- Formic acid and acetaldehyde — reported as the characteristic process impurities.
- Permanganate time and colour — the sensitive tests for oxidisable contamination.
Common Process Problems & Likely Causes
When acetic acid causes trouble, it is usually iodide, iron, water or freezing. This table is the shortcut our technical desk works through before anyone opens a complaint file.
| Symptom | Likely cause | What to check |
|---|---|---|
| VAM catalyst activity falling | Iodide carry-over from the carbonylation route | Iodide figure in ppb and guard bed condition |
| Solid acid in drums or lines | Temperature below 16.6 °C | Storage temperature, tracing and heating provision |
| Drum or line split in cold weather | Expansion on freezing in a full container | Ullage, storage temperature and heating |
| Product discolouration | Iron pick-up from carbon steel equipment | Iron result and material of construction |
| Rapid corrosion of stainless equipment | Dilute acid, chloride contamination or high temperature | Water content, chloride and operating temperature |
| Permanganate time short | Oxidisable contamination in transfer or storage | Permanganate result and line cleanliness |
Packaging, Storage & Shipping
- Standard packing. 200 L lined or stainless drums, IBCs, ISO tank containers and bulk parcels.
- Temperature control. Keep above 20 °C. Glacial acetic acid freezes at 16.6 °C and expands as it does so.
- Material compatibility. Stainless steel 316 or lined vessels. Carbon steel, aluminium, galvanised steel and copper alloys are all attacked.
- Ullage. Never fill containers completely; expansion on freezing splits full drums.
- Storage. Cool, ventilated, bunded corrosive storage away from bases, oxidisers and ignition sources.
- Segregation. Keep apart from bases, carbonates, oxidisers, chromates and permanganates — reactions are vigorous.
- Shelf life. Indefinite in sealed stainless or lined storage. Colour, iron and permanganate time are the practical checks.
- Transport classification. UN 2789, acetic acid glacial, Class 8 corrosive with subsidiary 3 flammable, packing group II.
Hazards & Safe Handling
Glacial acetic acid is corrosive and flammable. It causes severe burns on contact, and the vapour is strongly irritating to eyes and respiratory tract.
- Corrosivity. Causes severe skin burns and serious eye damage at glacial strength. Full face and body protection is required for transfer work.
- Flammability. Flash point about 39 °C with a flammable range of roughly 4 to 17%. Control ignition sources in storage and transfer areas.
- Vapour irritation. Strongly irritating to eyes, nose and throat. The sharp odour gives warning but is not a reliable exposure measure.
- Occupational exposure. Typical limits are around 10 ppm as an 8-hour average; confirm the limit in your jurisdiction.
- Freezing and expansion. Solidifying acid expands and can rupture drums and lines. This is a physical hazard as much as a logistics one.
- Reactivity. Reacts vigorously with bases, carbonates and strong oxidisers. Segregate strictly.
- PPE. Acid-resistant gloves, goggles and face shield, apron, and respiratory protection for any breach of containment.
- Environment. Lowers pH in watercourses; neutralise and contain spills.
Regulatory & Compliance Notes
Acetic acid is regulated as a corrosive and flammable liquid, with food and pharmaceutical grades under additional rules. The notes below are orientation rather than legal advice.
- GHS classification. Flammable liquid Category 3 and skin corrosion Category 1A. The SDS carries the full hazard statements.
- Dangerous goods transport. UN 2789 for glacial and strong solutions, Class 8 with subsidiary 3, PG II. ADR, IMDG, IATA and DOT rules apply.
- Food additive status. Approved as a food acidulant and preservative; food grades must meet FCC or equivalent specifications.
- Pharmacopoeial grades. USP, BP and EP grades carry additional identity, residue and heavy metal requirements.
- REACH and inventories. Registered under EU REACH and listed on the major chemical inventories.
- Quality agreements. VAM and PTA producers commonly expect documented iodide, iron and permanganate limits with change control.
We Supply Acetic Acid Worldwide
Chelora Chemicals is a supplier and export partner, not a single-plant trader. We ship Acetic Acid from India and from partner sources to customers across Asia, Europe, the Middle East, Africa, and North and South America, handling the export documentation, transport paperwork and freight so the material arrives ready to use.
- Incoterms. EXW, FOB, CIF, CFR and DAP quoted to suit your purchasing terms and freight arrangements.
- Ports. Regular shipments through Nhava Sheva (JNPT) and Mundra, with other ports arranged where routing and cargo rules allow.
- Documentation. Commercial invoice, packing list, certificate of origin, COA, SDS and the transport declaration issued as a complete set.
- Flexible volumes. From a pallet of lined drums up to repeat bulk shipments on a supply contract.
- Supply continuity. Because we are independent of any one producer, a plant turnaround or a shipping disruption at one source does not have to become your stock-out.
Buying Acetic Acid from Chelora
We are an independent sourcing and supply partner. For acetic acid that means settling three things at enquiry: the grade and iodide ceiling, the stainless or lined handling route into your tankage, and the heating provision, because this product freezes at 16.6 °C.
- Documentation on every lot. Batch-specific COA (purity, water, freezing point, iron), plus SDS and the full transport paperwork.
- Analysis before commitment. Representative analysis shared ahead of a commercial order so your lab can qualify the material.
- Quantities. From a pallet of lined drums through to full bulk shipments on contract supply.
- Grade matching. Glacial, food or pharmacopoeial grade to the iodide, iron and permanganate limits your process requires.
- Inspection. Independent third-party inspection available at loading when the contract requires it.
- Related products. Methanol, Vinyl Acetate Monomer, Ethyl Acetate and other feedstocks alongside Acetic Acid from one supplier.
How ordering works
- Send the enquiry. Product, grade or purity, quantity, destination port and the Incoterm you buy on. If you have a spec sheet, attach it — it saves a round trip.
- We quote. Price, lead time, packing format and a sample COA, normally within one working day.
- Qualify the supply. For first orders or critical applications, we share the analysis and handling documentation so your technical and safety teams can sign off before you commit.
- Confirm the order. Proforma invoice issued; payment terms agreed against the volume and the relationship.
- Allocation and QC. Material allocated and released against a batch-specific COA, with an independent inspection where the contract calls for it.
- Ship and document. Filled, labelled and loaded with the full export document set, and tracked through to arrival.
Acetic Acid — Common Questions
The questions our technical desk is asked most often about Acetic Acid. If yours isn't here, call or email and you will reach someone who knows the chemistry.
What is the CAS number of acetic acid?
The CAS number for acetic acid is 64-19-7, and its EC number is 200-580-7. Its molecular formula is C₂H₄O₂ with a molecular weight of 60.05 g/mol, and it is classified under HS code 2915.21.
What is acetic acid used for?
Mainly for vinyl acetate monomer and as the reaction solvent in purified terephthalic acid manufacture. It also goes to acetate esters, acetic anhydride, textile processing, food acidulation and pharmaceutical synthesis.
Do you supply acetic acid worldwide?
Yes. Chelora Chemicals supplies and exports glacial acetic acid worldwide — across Asia Pacific, Europe, the Middle East, Africa and the Americas, as well as throughout India. Every consignment carries the COA, the SDS and the dangerous-goods documentation.
What does glacial mean?
Near-anhydrous acetic acid, typically 99.85% or better. The name comes from the ice-like crystals it forms when it freezes at 16.6 °C, which is well within normal ambient range.
How is acetic acid manufactured?
Almost entirely by carbonylating methanol with carbon monoxide over a rhodium or iridium catalyst with an iodide promoter, in the Monsanto or Cativa processes. Food vinegar is produced separately by fermentation.
Why is iodide specified in parts per billion?
Because residual iodide from the carbonylation catalyst poisons the palladium catalyst in VAM plants and the oxidation catalyst in PTA units. It is the single most important trace specification for downstream users.
Is acetic acid hazardous?
Yes. Glacial acetic acid is corrosive, causing severe skin burns and serious eye damage, and it is a flammable liquid with a flash point near 39 °C. The vapour is strongly irritating.
What are the UN number and transport class?
UN 2789, acetic acid glacial, Class 8 corrosive with subsidiary risk 3 flammable, packing group II. ADR, IMDG, IATA and DOT rules apply.
How should acetic acid be stored?
In 316 stainless steel or lined vessels above 20 °C, in bunded corrosive storage away from bases and oxidisers, with ullage left in containers because the acid expands when it freezes.
What materials are compatible with acetic acid?
316 stainless steel, certain plastics and lined vessels. Carbon steel, aluminium, galvanised steel and copper alloys are all attacked. Dilute acid is actually more aggressive to stainless than glacial.
What packing sizes and order quantities are available?
200 L lined or stainless drums, IBCs, ISO tank containers and bulk parcels. Orders run from a pallet of drums up to repeat bulk cargoes on contract supply.
What is the typical shelf life?
Indefinite in sealed stainless or lined storage. Colour, iron content and permanganate time are the practical checks on older material.
Ready to source Acetic Acid?
Send us your specification, grade and annual volume. You will get a price, a realistic lead time and a sample COA from someone who understands what the material has to do in your process — delivered anywhere in the world.