HazmatTable logoHAZMATTABLE
UN identification number

UN1418: Magnesium

As listed: Magnesium, powder or Magnesium alloys, powder

UN1418 appears 3 times in the Hazardous Materials Table (49 CFR §172.101). Hazard class 4.3, packing group I, II, III.

ID numberUN1418
Hazard class4.3
Packing groupI, II, III
Label codes4.3, 4.2

All §172.101 entries for UN1418

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

What it means

4.3
Class 4.3 — Dangerous when wet. Materials that give off flammable or toxic gas when they contact water.

Packing group ranks danger within the class: PG I = great danger; PG II = medium danger; PG III = minor danger.

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

UN numbers are recognized for international and domestic transport.

Example basic description

UN1418, Magnesium, powder or Magnesium alloys, powder, 4.3, 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 UN1418 in the current PHMSA Emergency Response Guidebook.
How to Read a Hazmat Table Entry poster
Free download

Get the HazmatTable Field Guide poster pack

8 printable hazmat reference posters — reading a table entry, hazard classes, placards, segregation, shipping papers and more. Free, sent to your inbox.

Get the free pack →

Common questions about UN1418

What is UN1418?

UN1418 is the identification number for Magnesium, powder or Magnesium alloys, powder in the DOT Hazardous Materials Table (49 CFR §172.101).

What hazard class is UN1418?

UN1418 is listed under hazard class 4.3 (dangerous when wet).

What packing group is UN1418?

Packing group for UN1418: I, II, III. Where several rows exist, the packing group that fits your material decides which row applies.

Looking up materials every day? Unlimited searches are $5/mo — or add AI Search to ask questions in plain English.
See plans →
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.