DOT transport classification
UN number by concentration
Which UN number a chemical solution ships under depends on its concentration: sulfuric acid is UN2796 at or below 51% and UN1830 above it; hydrogen peroxide is unregulated below 8%, UN2984 from 8% to 20%, and UN2014 from 20% to 60%. Per-chemical references built from 49 CFR 172.101.
10 chemical families · Source: 49 CFR 172.101
Classification changes with concentration
| Chemical | CAS | Bands |
|---|---|---|
| Acetic acid | 64-19-7 | ≤10% → not regulated; >10% and <50% → UN2790; ≥50% and ≤80% → UN2790; >80% → UN2789 |
| Ammonia solution (ammonium hydroxide) | 1336-21-6 | ≤10% → not regulated; >10% and ≤35% → UN2672; >35% → UN2073 |
| Hydrogen peroxide, aqueous solution | 7722-84-1 | <8% → not regulated; ≥8% and <20% → UN2984; ≥20% and ≤60% → UN2014; >60% → UN2015 |
| Nitric acid | 7697-37-2 | <65% → UN2031; ≥65% and ≤70% → UN2031; >70% → UN2031 |
| Sulfuric acid | 7664-93-9 | ≤51% → UN2796; >51% → UN1830 |
Classification does not change with concentration
These are the chemicals most often misclassified, because it is natural to assume a percentage decides the answer. For some it never changes; for others the packing group is set by a laboratory test criterion rather than a number in the table.
| Chemical | CAS | What decides it |
|---|---|---|
| Hydrochloric acid (muriatic acid) | 7647-01-0 | packing group per 49 CFR 173.137 |
| Isopropanol (isopropyl alcohol) | 67-63-0 | packing group per 49 CFR 173.121 |
| Phosphoric acid solution | 7664-38-2 | One classification at all commercial strengths (UN1805, PG III) |
| Sodium hydroxide solution (caustic soda) | 1310-73-2 | packing group per 49 CFR 173.137 |
| Sodium hypochlorite solution | 7681-52-9 | packing group per 49 CFR 173.137 |