a. Flash Point. The flash point is the lowest temperature at which a liquid
gives off enough vapor to ignite in the presence of an ignition source, such as a match,
spark, or cigarette. Flammable liquids have a flash point below 100F. In general,
materials with lower flash points are more hazardous than materials with higher flash
b. Flammable Limits. The lower explosive limit (LEL) is the minimum amount
of airborne chemical that must be present in an air-chemical mixture to make it
explosive. The upper explosive limit (UEL) is the maximum amount of airborne
chemical that can be present in an air-chemical mixture and still have it be explosive. A
low LEL or wide explosive range is most hazardous.
Extinguishing Media. The MSDS informs you of what type of fire
extinguisher or material should be used to put out a fire.
d. Special Fire and Explosion Hazards. The information given is instructions
on how professional fire fighters should put out a fire.
e. Unusual Fire and Explosion Hazards. The information given will state if
the product is a fire hazard and whether or not it will explode.
4-21. REACTIVITY DATA (SECTION V)
The reactivity data section of the MSDS lists conditions to avoid for unstable
chemicals and polymerization hazards and incompatible reaction of materials. The
conditions to avoid are those that might cause the chemical to decompose (break down
into simpler molecules) or to polymerize (self-react to form larger molecules). Reactive
chemicals become hazardous when in contact with certain other chemical materials .
Contact may cause a fire, explosion, or other violent chemical reaction. It may also
produce or release a hazardous chemical. For this reason, the reactivity data section
lists materials to avoid for reactive chemicals. The following information is furnished.
Stability. Unstable or stable is checked and any conditions to avoid are
b. Incompatibility. Materials to avoid, if any, are listed. Whenever the MSDS
lists any materials to avoid, the chemical is reactive.
Hazardous Decomposition or By-Products. Any chemicals listed will be
toxic gases that are formed when the chemical burns or decomposes. Carbon
monoxide, phosgene, and hydrogen chloride are deadly.
d. Hazardous Polymerization. The "may" or "will not occur" will be checked
and conditions to avoid, if any, will be listed.