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UN identification number

UN3517: Adsorbed gas

As listed: Adsorbed gas, toxic, flammable, corrosive, n.o.s. Inhalation hazard zone A

UN3517 appears 4 times in the Hazardous Materials Table (49 CFR §172.101). Hazard class 2.3.

ID numberUN3517
Hazard class2.3
Packing groupnot assigned
Label codes2.3, 2.1, 8

All §172.101 entries for UN3517

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

What it means

2.3
Class 2.3 — Poisonous (toxic) gas. Gases known to be toxic to humans when inhaled.

Label codes (column 6): 2.3, 2.1, 8 → Poison gas label + subsidiary Flammable gas, Corrosive labels.

UN numbers are recognized for international and domestic transport.

Example basic description

UN3517, Adsorbed gas, toxic, flammable, corrosive, n.o.s., 2.3

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 UN3517 in the current PHMSA Emergency Response Guidebook.
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Common questions about UN3517

What is UN3517?

UN3517 is the identification number for Adsorbed gas, toxic, flammable, corrosive, n.o.s. in the DOT Hazardous Materials Table (49 CFR §172.101).

What hazard class is UN3517?

UN3517 is listed under hazard class 2.3 (poisonous (toxic) gas).

What packing group is UN3517?

Packing group for UN3517: not assigned. 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.