UN/NA Number Reference
DOT Class 8 Corrosive placard

UN 1910: Calcium oxide

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 1910 is assigned the proper shipping name Calcium oxide in the U.S. DOT Hazardous Materials Table (49 CFR 172.101). It is classified as a Class 8 Corrosive material, Packing Group III. Required label(s): 8.

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 157)

Hazards: TOXIC and/or CORROSIVE. Reacts with water. Non-combustible in themselves.

Fire: DO NOT use water. Dry chemical, CO2, dry sand.

Spill: Do not touch. Keep material dry.

Chemical and Physical Properties

Calcium oxide appears as an odorless, white or gray-white solid in the form of hard lumps. A strong irritant to skin, eyes and mucous membranes. Used in insecticides and fertilizers.

CAS Number: 1305-78-8
Molecular Formula: CaO
Molecular Weight: 56.08 g/mol
Color / Form: Grey-white, cubic crystals
Odor: Odorless
Boiling Point: 5162 F
Melting Point: 4662 °F (NIOSH, 2024)
Flash Point: Not flammable
Autoignition: Not flammable (USCG, 1999)
Specific Gravity: 3.3 (sinks in water)
Vapor Pressure: 0 mmHg (approx)
Water Solubility: Reacts with water
pH: SATURATED SOLN IN WATER IS ABOUT 12.8

Regulatory Data

OSHA PEL
TWA 5 mg/m 3
NIOSH REL
TWA 2 mg/m 3
IDLH
25 mg/m 3

Special Provisions

49 CFR 172.102 special provision codes for this entry: IB8, IP3, T1, TP33. 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 1910 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.