UN/NA Number Reference
DOT Class 4.1 Flammable Solid placard

UN 2858: Zirconium, dry, coiled wire, finished metal sheets, or strip

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 2858 is assigned the proper shipping name Zirconium, dry, coiled wire, finished metal sheets, or strip in the U.S. DOT Hazardous Materials Table (49 CFR 172.101). It is classified as a Class 4.1 Flammable Solid material, Packing Group III. Required label(s): 4.1.

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 170)

Hazards: Flammable. May react with water producing flammable hydrogen gas. May reignite after extinguishing.

Fire: DO NOT use water, foam, or CO2. Use dry sand, dry sodium chloride powder, or Met-L-X.

Spill: Do not touch. Cover with dry sand or earth. Keep dry. Do not use water.

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
Vapor Pressure: 0 mmHg
Water Solubility: Insoluble in water

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: A1, W100. 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.

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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.