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UN identification number

UN3394: Organometallic substance

As listed: Organometallic substance, liquid, pyrophoric, water-reactive

UN3394 appears 1 time in the Hazardous Materials Table (49 CFR §172.101). Hazard class 4.2, packing group I.

ID numberUN3394
Hazard class4.2
Packing groupI
Label codes4.2, 4.3

All §172.101 entries for UN3394

Proper shipping nameClassPGLabels
Organometallic substance, liquid, pyrophoric, water-reactive4.2I4.2, 4.3

Open any entry for packaging sections, special provisions, air limits and vessel stowage.

What it means

4.2
Class 4.2 — Spontaneously combustible. Materials that can heat up and ignite on their own in air.

Packing group ranks danger within the class: PG I = great danger.

Label codes (column 6): 4.2, 4.3 → Spontaneously combustible label + subsidiary Dangerous when wet label.

UN numbers are recognized for international and domestic transport.

Example basic description

UN3394, Organometallic substance, liquid, pyrophoric, water-reactive, 4.2, PG I

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

  1. Match the name. Compare your SDS Section 14 to the proper shipping names above and pick the row with your packing group.
  2. Read the special provisions on the entry page (§172.102) — they can add limits or exceptions.
  3. Check packaging — the entry page lists the Part 173 sections for exceptions, non-bulk and bulk.
  4. Labels & placards. Placarding depends on class and quantity — see Table 1 vs Table 2.
  5. Emergency response. Find the response guide for UN3394 in the current PHMSA Emergency Response Guidebook.
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Common questions about UN3394

What is UN3394?

UN3394 is the identification number for Organometallic substance, liquid, pyrophoric, water-reactive in the DOT Hazardous Materials Table (49 CFR §172.101).

What hazard class is UN3394?

UN3394 is listed under hazard class 4.2 (spontaneously combustible).

What packing group is UN3394?

Packing group for UN3394: I. Where several rows exist, the packing group that fits your material decides which row applies.

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Source: Hazardous Materials Table (49 CFR §172.101), eCFR.gov — current as of Oct 23, 2026. View the official table. Reference only — verify current requirements before shipping.