UN/NA Number Reference

DOT Class 4.2 Spontaneously Combustible placard

UN 2008: Zirconium powder, dry

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 2008 is assigned the proper shipping name Zirconium powder, dry in the U.S. DOT Hazardous Materials Table (49 CFR 172.101). It is classified as a Class 4.2 Spontaneously Combustible material, Packing Group I. Required label(s): 4.2.

Packing group indicates the degree of danger within a hazard class: PG I is high danger, PG II medium, PG III low. The proper shipping name, hazard class, UN number, and packing group together form the basic shipping description that must appear on shipping papers and, where required, on the package and placard.

Emergency Response (ERG Guide 135)

Hazards: Spontaneously combustible. May reignite after fire is extinguished. May burn rapidly.

Fire: Small: dry chemical, sand, earth. Large: flooding water. Do NOT use foam.

Spill: Do not touch. Cover with dry earth/sand. Do not get water on spilled substance.

Chemical and Physical Properties

Zirconium powder wet appears as a gray amorphous sludge with not less than 25% water.

CAS Number: 7440-67-7

Molecular Formula: Zr

Molecular Weight: 91.22 g/mol

Color / Form: Bluish-black, amorphous powder or grayish-white lustrous metal (platelets or flakes) of hexagonal lattice below 865 °C; body-centered cubic above 865 °C

Boiling Point: 6471 F

Melting Point: 3375 °F (NIOSH, 2024)

Autoignition: Cloud ignition temperature: 330 °C

Specific Gravity: 6.51 (sinks in water)

Vapor Pressure: 0 mmHg (approx)

Water Solubility: Insoluble

Regulatory Data

OSHA PEL

5 5 mg/m 3 (ST) 10 mg/m 3

NIOSH REL

TWA 5 mg/m 3 ST 10 mg/m 3 [*Note: The REL applies to all zirconium compounds (as Zr) except Zirconium tetrachloride.]

IDLH

25 mg/m 3 (as Zr)

Special Provisions

49 CFR 172.102 special provision codes for this entry: T21, TP7, TP33, W31. These codes modify the general requirements (packaging, quantity limits, exceptions) for this specific material. Look up each code in 49 CFR 172.102 for the full text.

Need the full interactive record? Open UN 2008 in the SpillNerd lookup tool for the live database entry with placard graphics, GHS pictograms, full segregation tables, and synonym search. For another material, use the UN number and chemical lookup.

Reference data compiled from the DOT Hazardous Materials Table (49 CFR 172.101), the 2024 Emergency Response Guidebook, and public chemical databases (PubChem, NIOSH, EPA). Always verify the correct shipping description against the current regulation and the manufacturer's SDS Section 14 before shipping.