UN/NA Number Reference
DOT Class 4.1 Flammable Solid placard

UN 1344: Trinitrophenol (picric acid), wetted

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 1344 is assigned the proper shipping name Trinitrophenol (picric acid), wetted 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 I. 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 113)

Hazards: Picric acid, picrates, and similar wetted explosives. KEEP WET - dry material may detonate from friction, heat, or shock. Heating reduces water content and increases explosion risk.

Fire: Flood with water from maximum distance. Cool containers with water. DO NOT allow material to dry out. Evacuate if fire reaches cargo.

Spill: Do not touch. Keep material wet at all times. Cover with wet sand, wet earth, or water-saturated material. Eliminate friction sources. No metal-on-metal contact.

Chemical and Physical Properties

Picric acid, [dry] appears as yellow crystals. An explosive. Specific gravity 1.767. Melting point 251.2 °F (121.8 °C). Explodes at 572 °F. Toxic by ingestion.

CAS Number: 88-89-1
Molecular Formula: C6H3N3O7
Molecular Weight: 229.10 g/mol
Color / Form: Pale yellow crystals
Odor: Odorless
Boiling Point: 572 F
Melting Point: 252 °F (NIOSH, 2024)
Flash Point: 302 F
Autoignition: 572 °F (NTP, 1992)
Specific Gravity: 1.76
Vapor Pressure: 1 mmHg
Vapor Density: 7.9 (heavier than air)
Water Solubility: 1 % (NIOSH, 2024)
Log P: log Kow = 1.44

Regulatory Data

CERCLA RQ (40 CFR 302.4)
1 lb
OSHA PEL
TWA 0.1 mg/m 3 [skin]
NIOSH REL
TWA 0.1 mg/m 3 ST 0.3 mg/m 3 [skin]
IDLH
75 mg/m 3

A release of this material at or above its CERCLA reportable quantity (1 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: 162, A8, A19, N41, 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 1344 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.