Acetic acid (CAS 64-19-7) is one of the oldest and most versatile industrial chemicals. At 100% purity it is called glacial acetic acid — a colourless liquid with a sharp, pungent odour. At lower concentrations it is familiar as vinegar. Industrially, it is produced predominantly via the carbonylation of methanol (Monsanto / Cativa process) and appears in the supply chain of an extraordinary range of industries.
This guide covers the commercial grade spectrum, how each grade is used in manufacturing, and what to verify when sourcing in India.
Grade Spectrum
| Grade | Purity | Key Standards | Typical Use |
|---|---|---|---|
| Glacial Acetic Acid | ≥99.5% | BIS IS:695 / Technical | Chemical synthesis, plastics, fibres |
| Technical Grade | 98–99.5% | Manufacturer spec | Rubber, textiles, dyes, adhesives |
| Food Grade (FCC) | ≥99.5% | Food Chemicals Codex | Preservatives, food acidulants, vinegar production |
| Pharma Grade (BP/USP) | ≥99.5% | BP / USP | Pharmaceutical manufacturing, buffer solutions |
| Reagent / AR Grade | ≥99.8% | ACS / analytical | Laboratories, analytical chemistry |
In practice, glacial acetic acid and technical grade differ more in impurity profile and documentation than purity percentage. The critical specification for most industrial buyers is the assay (by titration or GC), the colour (APHA), and the absence of formic acid — which can be a by-product in some manufacturing processes and is undesirable in most end-uses.
Industrial Applications
Rubber industry: Acetic acid is the primary coagulating agent for natural rubber latex. Diluted to 1–5% concentration, it is added to fresh latex to precipitate the rubber solids. This is one of the largest industrial uses of acetic acid in South India, given the rubber processing industries in Kerala and Tamil Nadu.
Textiles and dyeing: Used to adjust dye bath pH in dyeing synthetic and natural fibres. Acetic acid creates the mildly acidic environment (pH 4–5) needed for acid dyes to bond with nylon and wool fibres. Technical grade is standard for this application.
Pharma and biochemistry: BP/USP grade is used in buffer preparation (acetate buffers), as a pH-adjusting agent in topical preparations, and in synthesis of acetate esters used as solvents and pharmaceutical intermediates.
Chemical synthesis intermediates: Glacial acetic acid is the feedstock for vinyl acetate monomer (VAM), acetic anhydride, ethyl acetate, and a range of acetate esters and dyes. These derivatives make acetic acid a cornerstone of the organic chemical industry.
Metal cleaning and surface treatment: Dilute solutions (5–30%) are used for pickling and brightening of certain metals and in electroplating bath formulations.
How to Specify Correctly
When placing a purchase order, specify:
- Assay: minimum percentage (e.g., "≥99.5% as acetic acid")
- Grade and standard: "Technical", "Food Grade FCC", or "BP Glacial Acetic Acid"
- CAS Number: 64-19-7 (confirms you are ordering acetic acid, not an acetate ester)
- Packaging: drum, carboy, or tanker; and whether HDPE or SS container is required
- CoA requirements: assay, APHA colour, iron content (for pharma grade), formic acid content
Storage and Handling Notes
Glacial acetic acid is corrosive (UN 2789, Class 8) and flammable (flash point 39°C). Store away from oxidising agents and bases. HDPE and stainless steel are compatible storage materials; avoid aluminium above 65% concentration. Appropriate PPE includes acid-resistant gloves and face protection.
Sourcing From SPC
Supreme Petro Chemicals supplies acetic acid in technical and food grades for manufacturers across South India. Available in carboys (35 kg), 200-litre MS drums, and tanker loads. Contact us for current pricing, or browse our acids catalog.