UN identification number

UN1381: Phosphorus

As listed: Phosphorus, white dry or Phosphorus, white, under water or Phosphorus white, in solution or Phosphorus, yellow dry or Phosphorus, yellow, under water or Phosphorus, yellow, in solution

UN1381 appears 1 time in the Hazardous Materials Table (49 CFR §172.101). Hazard class 4.2, packing group I.

ID numberUN1381

Hazard class4.2

Packing groupI

Label codes4.2, 6.1

All §172.101 entries for UN1381

Proper shipping name	Class	PG	Labels
Phosphorus, white dry or Phosphorus, white, under water or Phosphorus white, in solution or Phosphorus, yellow dry or Phosphorus, yellow, under water or Phosphorus, yellow, in solution	4.2	I	4.2, 6.1

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, 6.1 → Spontaneously combustible label + subsidiary Poison / Toxic label.

UN numbers are recognized for international and domestic transport.

Example basic description

UN1381, Phosphorus, white dry or Phosphorus, white, under water or Phosphorus white, in solution or Phosphorus, yellow dry or Phosphorus, yellow, under water or Phosphorus, yellow, in solution, 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

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 UN1381 in the current PHMSA Emergency Response Guidebook.

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Common questions about UN1381

What is UN1381?

UN1381 is the identification number for Phosphorus, white dry or Phosphorus, white, under water or Phosphorus white, in solution or Phosphorus, yellow dry or Phosphorus, yellow, under water or Phosphorus, yellow, in solution in the DOT Hazardous Materials Table (49 CFR §172.101).

What hazard class is UN1381?

UN1381 is listed under hazard class 4.2 (spontaneously combustible).

What packing group is UN1381?

Packing group for UN1381: 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.