UN/NA Number Reference
DOT Class 3 Flammable Liquid placard

UN 1198: Formaldehyde solution, flammable

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 1198 is assigned the proper shipping name Formaldehyde solution, flammable in the U.S. DOT Hazardous Materials Table (49 CFR 172.101). It is classified as a Class 3 Flammable Liquid material, Packing Group III. Required label(s): 3, 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 132)

Hazards: HIGHLY FLAMMABLE. CORROSIVE. Causes burns. Vapors may form explosive mixture with air.

Fire: Alcohol-resistant foam, dry chemical, CO2. Do not use water jet. Cool containers.

Spill: Eliminate ignition sources. Do not touch. Stop leak if safe. Use foam.

Chemical and Physical Properties

Solids containing varying amounts of formaldehyde, probably as paraformaldehyde (polymers of formula HO(CH2O)xH where x averages about 30). A hazard to the environment. Immediate steps should be taken to limit spread to the environment.

CAS Number: 50-00-0
Molecular Formula: CH2O
Molecular Weight: 30.03 g/mol
Color / Form: Nearly colorless gas [Note: Often used in an aqueous solution]. /Pure formaldehyde/
Odor: Pungent, suffocating odor
Boiling Point: 214°F (101°C) at 37%
Melting Point: -134 °F (NIOSH, 2024)
Flash Point: 185°F (85°C) at 37%
Autoignition: 806 °F (USCG, 1999)
Specific Gravity: 1.08 (37% solution, sinks)
Vapor Pressure: 1.3 mmHg
Vapor Density: 1.03 (about same as air)
Water Solubility: Miscible (fully soluble)
Log P: 0.35
pH: pH: 2.8 to 4.0 /Formaldehyde soln/

Regulatory Data

CERCLA RQ (40 CFR 302.4)
100 lb
EPCRA TPQ (40 CFR 355)
500 lb
OSHA PEL
0.75 ppm (ST) 2 ppm See Section 5217
NIOSH REL
Ca TWA 0.016 ppm C 0.1 ppm [15-minute]
IDLH
Ca [20 ppm]
RCRA Waste Code(s)
[object Object]

A release of this material at or above its CERCLA reportable quantity (100 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: 176, B1, IB3, T4, TP1. 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 1198 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.