UN3121: Oxidizing solid, water reactive, n.o.s
UN3121 appears 2 times in the Hazardous Materials Table (49 CFR §172.101). Hazard class 5.1, packing group I, II.
All §172.101 entries for UN3121
| Proper shipping name | Class | PG | Labels |
|---|---|---|---|
| Oxidizing solid, water reactive, n.o.s | 5.1 | I | 5.1, 4.3 |
| Oxidizing solid, water reactive, n.o.s | 5.1 | II | 5.1, 4.3 |
Open any entry for packaging sections, special provisions, air limits and vessel stowage.
What it means
Packing group ranks danger within the class: PG I = great danger; PG II = medium danger.
Label codes (column 6): 5.1, 4.3 → Oxidizer label + subsidiary Dangerous when wet label.
UN numbers are recognized for international and domestic transport.
Example basic description
Proper shipping name shown without the table's italic descriptive text. Order per §172.202: ID number, proper shipping name, hazard class, packing group. Example only — add technical names, “RQ”, quantities and other elements your shipment requires.
What to check next
- Match the name. Compare your SDS Section 14 to the proper shipping names above and pick the row with your packing group.
- Read the special provisions on the entry page (§172.102) — they can add limits or exceptions.
- Check packaging — the entry page lists the Part 173 sections for exceptions, non-bulk and bulk.
- Labels & placards. Placarding depends on class and quantity — see Table 1 vs Table 2.
- Emergency response. Find the response guide for UN3121 in the current PHMSA Emergency Response Guidebook.
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Common questions about UN3121
What is UN3121?
UN3121 is the identification number for Oxidizing solid, water reactive, n.o.s in the DOT Hazardous Materials Table (49 CFR §172.101).
What hazard class is UN3121?
UN3121 is listed under hazard class 5.1 (oxidizer).
What packing group is UN3121?
Packing group for UN3121: I, II. Where several rows exist, the packing group that fits your material decides which row applies.