Facts about flammable and combustible liquids:

• Flammable and combustible liquids ignite easily and burn with extreme rapidity.
• Flammability is determined by the flash point of a material.
• Flash point is the minimum temperature at which a liquid forms a vapor above its surface in sufficient concentration that it can be ignited.
• Flammable liquids have a flash point of less than 100°F. Liquids with lower flash points ignite easier.
• Combustible liquids have a flashpoint at or above 100°F.
• The vapor burns, not the liquid itself. The rate at which a liquid produces flammable vapors depends upon its vapor pressure.
• The vaporization rate increases as the temperature increases. Therefore, flammable and combustible liquids are more hazardous at elevated temperatures than at room temperature.

Restrictions and guidelines: Because their vapors ignite and burn easily, flammable and combustible liquids have strict storage requirements. The hazard classification of a liquid determines the type and size of container in which it can be stored. For more information, see:

• Container Size and Quantity Limits
• Flammable and Combustible Liquids Storage Guidelines.

Hazard classifications: The National Fire Protection Association (NFPA) has established the following hazard classifications for flammable and combustible liquids:

Questions?

• If you are a research employee, contact the EH&S Research Assistance Program specialist assigned to your building.
• If you are a non-research employee, contact an EH&S general safety specialist, (858) 534-7513.