UN/NA Number Reference

UN 1334: Naphthalene, crude

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 1334 is assigned the proper shipping name Naphthalene, crude 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 133)

Hazards: Flammable. May be ignited by friction, heat, sparks. May burn rapidly with flare-burning effect.

Fire: Water spray, foam, dry chemical. Some may be extinguished with CO2.

Spill: Eliminate ignition sources. Do not touch. Cover with dry earth, sand, or non-combustible material.

Chemical and Physical Properties

Naphthalene appears as a white crystalline volatile solid with a strong coal-tar odor. The solid is denser than water and insoluble in water. Burns, but may be difficult to ignite. In the molten form it is very hot. Exposure to skin must be avoided. Also the vapors given off by the material may be toxic. Used as a moth repellent, fumigant, lubricants, and to make other chemicals, and for many other uses

CAS Number: 91-20-3

Molecular Formula: C10H8

Molecular Weight: 128.17 g/mol

Color / Form: White crystalline flakes ... Plates from ethanol

Odor: Aromatic odor

Boiling Point: 424°F (218°C)

Melting Point: 176.4 °F (NTP, 1992)

Flash Point: 174°F (79°C)

Autoignition: 979 °F (USCG, 1999)

Specific Gravity: 1.14 (sinks in water)

Vapor Pressure: 0.05 mmHg at 68 °F ; 1 mmHg at 126.7 °F (NTP, 1992)

Vapor Density: 4.42 (heavier than air)

Water Solubility: Insoluble

Log P: log Kow = 3.30

Regulatory Data

CERCLA RQ (40 CFR 302.4)

100 lb

OSHA PEL

TWA 10 ppm (50 mg/m 3 )

NIOSH REL

TWA 10 ppm (50 mg/m 3 ) ST 15 ppm (75 mg/m 3 )

IDLH

250 ppm

RCRA Waste Code(s)

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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: A1, B120, 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 1334 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.