UN/NA Number Reference
DOT Class 6.1 Toxic Substance placard

UN 1594: Diethyl sulfate

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 1594 is assigned the proper shipping name Diethyl sulfate in the U.S. DOT Hazardous Materials Table (49 CFR 172.101). It is classified as a Class 6.1 Toxic Substance material, Packing Group II. Required label(s): 6.1.

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 153)

Hazards: TOXIC. Combustible. Corrosive. Causes burns. Toxic fumes when heated.

Fire: Small: dry chemical, CO2, water spray. Large: water spray, foam.

Spill: Do not touch. Stop leak if safe. Use water spray to reduce vapor.

Chemical and Physical Properties

Diethyl sulfate appears as a clear colorless liquid with a peppermint odor. Burns, though may be difficult to ignite. Corrosive to metals and tissue. It is a potent alkylating agent. Flash point is 104 °C (219 °F) [Aldrich MSDS].

CAS Number: 64-67-5
Molecular Formula: C4H10O4S
Molecular Weight: 154.19 g/mol
Color / Form: Colorless, oily liquid ... darkens with age
Odor: Peppermint odor
Boiling Point: 409 F
Melting Point: -12 °F (USCG, 1999)
Flash Point: 220 F
Autoignition: 817 °F (USCG, 1999)
Specific Gravity: 1.1803 (sinks in water)
Vapor Pressure: 0.21 [mmHg]
Vapor Density: 5.31 (heavier than air)
Water Solubility: Miscible in alcohol and ether.
Log P: log Kow= 1.14

Regulatory Data

CERCLA RQ (40 CFR 302.4)
10 lb

A release of this material at or above its CERCLA reportable quantity (10 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: IB2, T7, TP2. 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 1594 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.