UN3138: Ethylene
As listed: Ethylene, acetylene and propylene in mixture, refrigerated liquid with at least 71.5 percent ethylene with not more than 22.5 percent acetylene and not more than 6 percent propylene
UN3138 appears 1 time in the Hazardous Materials Table (49 CFR §172.101). Hazard class 2.1.
All §172.101 entries for UN3138
Open any entry for packaging sections, special provisions, air limits and vessel stowage.
What it means
Label codes (column 6): 2.1 → Flammable gas 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 UN3138 in the current PHMSA Emergency Response Guidebook.
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Common questions about UN3138
What is UN3138?
UN3138 is the identification number for Ethylene, acetylene and propylene in mixture, refrigerated liquid in the DOT Hazardous Materials Table (49 CFR §172.101).
What hazard class is UN3138?
UN3138 is listed under hazard class 2.1 (flammable gas).
What packing group is UN3138?
Packing group for UN3138: not assigned. Where several rows exist, the packing group that fits your material decides which row applies.