UN/NA Number Reference
DOT Class 6.1 Toxic Substance placard

UN 2674: Sodium fluorosilicate

49 CFR 172.101 Hazardous Materials Table·ERG 2024

DOT Classification and Shipping

UN 2674 is assigned the proper shipping name Sodium fluorosilicate 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 III. 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 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

Pellets or Large Crystals; Dry Powder, Pellets or Large Crystals; Dry Powder

CAS Number: 16893-85-9
Molecular Formula: F6Na2Si
Molecular Weight: 188.055 g/mol
Color / Form: WHITE GRANULAR POWDER
Odor: Odorless
Melting Point: Melts at red heat with decomposition.
Specific Gravity: 2.7 g/cu cm.
Water Solubility: SOL IN 150 PARTS COLD, 40 PARTS BOILING WATER
pH: SOLN IN COLD WATER IS NEUTRAL

Special Provisions

49 CFR 172.102 special provision codes for this entry: 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 2674 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.