Sulfur Dioxide is a nonflammable, colourless, irritating, liquefied compressed gas packaged in cylinders under its own vapor pressure (34 psig at 70 °F). It has a suffocating door, detectable at 3-5 ppm, and leaves an acidic taste in the mouth (0.31 ppm). It is a toxic, corrosive gas that can cause severe chemical burns if inhaled or upon skin contact. When entering release areas wear Self Contained Breathing Apparatus (SCBA) if concentrations are unknown or exceed exposure limits.

PHYSICAL AND CHEMICAL PROPERTIES
Appearance, odor and state : colorless gas with sharp, suffocating, acidic odor.
Molecular weight : 64.2
Boiling point (at 1 atm) : 13.9 °F
Specific gravity (air =1) : 2.25
Freezing point / melting point (at 1 atm) : -103.92 °F
Vapor pressure (at 70 F (21.1 C)) : 35 psig
Gas density (at 70 F (21.1 C) and 1 atm) : 0.168 lb/ft3
NFPA Rating : Health: 3; Flammability: 0; Reactivity: 0
HMIS Rating : Health: 1; Flammability: 0; Reactivity: 0

TRANSPORT INFORMATION

DOT Shipping Name : Sulfur Dioxide
Hazard Class : 2.3
ID Number : UN 1079
Shipping Label(S) : Poison Gas (Primary), Corrosive

NIOSH: IDLH = 100 ppm

OSHA: PEL = 5 ppm