UN identification number

UN3318: Ammonia solution

As listed: Ammonia solution, relative density less than 0.880 at 15 degrees C in water, with more than 50 percent ammonia

UN3318 appears 2 times in the Hazardous Materials Table (49 CFR §172.101). Hazard class 2.3, 2.2.

ID numberUN3318

Hazard class2.3 2.2

Packing groupnot assigned

Label codes2.3, 8 / 2.2

All §172.101 entries for UN3318

Proper shipping name	Class	PG	Labels
Ammonia solution, relative density less than 0.880 at 15 degrees C in water, with more than 50 percent ammonia	2.3	—	2.3, 8
Ammonia solution, relative density less than 0.880 at 15 degrees C in water, with more than 50 percent ammonia	2.2	—	2.2

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.

2.2

Class 2.2 — Non-flammable, non-poisonous gas. Compressed gases that aren't flammable or toxic but can still be dangerous under pressure — for example nitrogen and compressed air.

Label codes (column 6): 2.3, 8 → Poison gas label + subsidiary Corrosive label · 2.2 → Non-flammable gas label.

UN numbers are recognized for international and domestic transport.

Example basic description

UN3318, Ammonia solution, 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

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 UN3318 in the current PHMSA Emergency Response Guidebook.

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Common questions about UN3318

What is UN3318?

UN3318 is the identification number for Ammonia solution in the DOT Hazardous Materials Table (49 CFR §172.101).

What hazard class is UN3318?

UN3318 is listed under hazard class 2.3, 2.2 (poisonous (toxic) gas).

What packing group is UN3318?

Packing group for UN3318: not assigned. Where several rows exist, the packing group that fits your material decides which row applies.

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← UN3317 All UN numbers All Class 2.3 materials UN3319 →

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.