UN/NA Number Reference
DOT Class 4.3 Dangerous When Wet placard

UN 1435: Zinc ashes

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 1435 is assigned the proper shipping name Zinc ashes in the U.S. DOT Hazardous Materials Table (49 CFR 172.101). It is classified as a Class 4.3 Dangerous When Wet material, Packing Group III. Required label(s): 4.3.

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 138)

Hazards: Corrosive. Reacts with water, produces corrosive/toxic gases. May ignite on water contact.

Fire: DO NOT use water. Use dry chemical, dry sand, soda ash.

Spill: Do not touch. Keep dry. Move from water source. Cover with dry earth.

Chemical and Physical Properties

Zinc ashes appears as a grayish colored powder. May produce toxic zinc oxide fumes when heated to very high temperatures or when burned. Insoluble in water. Used in paints, bleaches and to make other chemicals.

CAS Number: 7440-66-6
Molecular Formula: Zn
Molecular Weight: 65.4 g/mol
Color / Form: Bluish-white, lustrous metal; distorted hexagonal close-packed structure; when heated to 100-150 °C becomes malleable, at 210 °C becomes brittle and pulverizable
Boiling Point: 1665 F
Melting Point: 419
Autoignition: 460 °C
Specific Gravity: 7.133 g/cu cm
Vapor Pressure: 1.47X10-6 Pa (1.10X10-8 mm Hg) at 400 K (127 C)
Water Solubility: Soluble in acids and alkalies

Regulatory Data

CERCLA RQ (40 CFR 302.4)
1000 lb

A release of this material at or above its CERCLA reportable quantity (1000 lb) requires immediate notification to the National Response Center at 800-424-8802.

Special Provisions

49 CFR 172.102 special provision codes for this entry: A1, A19, B136, IB8, IP4, T1, TP33, 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.

Need the full interactive record? Open UN 1435 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.