Acetic acid: Characteristics
Why iodide traces worry vinyl acetate makers
What this tab covers The physical and chemical properties that set its grade, price and uses, with the commercial grades and the standards that define them.Acetic acid is sold as glacial (water-free) acid to tight purity limits, because VAM and PTA catalysts are sensitive to impurities. Buyers check purity, water, colour, permanganate time and iodide traces left by carbonylation. Freezing at 16.6 C matters for storage and transport.
Properties that matter commercially
| Property | Value / specification | Why it matters | Source |
|---|---|---|---|
| Purity | at least 99.8-99.85% glacial (indicative) | downstream catalysts and pharma | industry specs (indicative) |
| Water | at most about 0.1-0.15% (indicative) | anhydride and VAM processes | indicative |
| Iodide | low ppb levels for VAM grade (indicative) | poisons palladium VAM catalyst | indicative |
| Freezing point | 16.6 C | heated storage and tankers | physical data |
| Flash point | about 39 C | flammable classification | physical data |
Commercial grades
- Glacial technical grade
- VAM grade (low iodide)
- Food grade (E260)
- Pharma (IP/USP) grade
- Diluted acid solutions