FLAMMABLES

1. PROPERTIES OF FLAMMABLES Combustion (redox) reactions Solids, gases, most commonly liquids Fire Tetrahedron Ignition sources External- Internal – spontaneous comb.

2. DEFINITIONS / HAZARDS a. Flash Point Lowest temp. at which liquid gives off sufficient vapor to form ignitable mixture with air at or near surface of liquid when exposed to a spark. Examples – see handout Significance

b. Auto-ignition Temperature Temperature of flammable liquid at which self-sustained combustion occurs in absence of external ignition source. (internal ignition source – heat) Example Ether – C

c. Limits of Flammability LEL (Lower Explosion Limit) Minimum conc. of vapor in air below which a flame is not propegated when ignited. UEL (Upper Explosion Limit) Maximum conc. of vapor in air above which flame is not propegated when ignited. ** Significance of limits

3. CLASSIFICATION OF FLAMMABLES Class I A Class I B Class I C  73 0 F F  F > F Pentane Ether Acetaldehyde Ethanol Acetone Benzene p-Xylene Flash Point Boiling Point Examples

4. PECAUTIONARY MEASURES a. Reduce Possible Ignition Source No flames Sparking from electrical motors Ground and bond metal containers

b. Reduce Concentrating Vapors Minimize organic solvents poured down drain Proper ventilation Possibility of “Flashback” c. Proper Storage Containers Minimal size / type in lab Flammable Safety Cans Flammable Storage Cabinets

5. EMERGENCY SYSTEMS AND PRODEDURES Appropriate # and type extinguishers Fire Blanket Fire Drills Proper clean-up for spills Spill pillows Stop, drop, and roll method