UN/NA Number Reference
DOT Class 8 Corrosive placard

UN 2817: Ammonium hydrogen difluoride, solution

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 2817 is assigned the proper shipping name Ammonium hydrogen difluoride, solution in the U.S. DOT Hazardous Materials Table (49 CFR 172.101). It is classified as a Class 8 Corrosive material, Packing Group II. 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 154)

Hazards: TOXIC. Corrosive. Non-combustible but may decompose producing toxic fumes when heated.

Fire: Use agent appropriate for surrounding fire. Cool containers.

Spill: Do not touch. Avoid inhalation. Use water spray to reduce fumes.

Chemical and Physical Properties

Ammonium bifluoride, solid appears as a white crystalline solid. Soluble in water. Corrosive to tissue. Used to sterilize food processing equipment, in chemical analysis, for electroplating and for many other uses.

CAS Number: 1341-49-7
Molecular Formula: F2H5N
Molecular Weight: 57.044 g/mol
Color / Form: Rhombic or tetragonal crystals
Odor: Odorless
Boiling Point: 463.1 °F at 760 mmHg (Decomposes at 446 °F) (USCG, 1999)
Melting Point: 258 °F (USCG, 1999)
Specific Gravity: 1.5 at 68 °F (USCG, 1999) - Denser than water; will sink
Water Solubility: Solubility in 90% ethanol = 1.73X10+5 mg/L
pH: pH = 3.5 (5% solution)

Regulatory Data

CERCLA RQ (40 CFR 302.4)
100 lb

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: IB2, N34, T8, TP2, TP13. 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 2817 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.