: Invisible vapors may travel to source of ignition and flash back. Since vapors are heavier than air, dangerous concentrations may not be apparent to casual observation. Keep containers tightly closed, isolate from heat, electrical equipment, sparks and open flame. Closed containers may explode when exposed to extreme heat. Fire will produce dense black smoke containing hazardous products of combustion. Symptoms may not be immediately apparent. Obtain medical attention. This product may polymerize when its container is exposed to heat causing an increase in pressure resulting in a violent rupture. Special Fire Fighting Procedures: Water should be used to cool containers exposed to fire. Fire fighting personnel should wear self-contained breathing apparatus.