Session 5C

Control Procedures for Flammable and Combustible Liquids

Upon completion of this session, you will learn additional methods to protect yourself from the hazards of flammable and combustible liquids.

It should  take you about 10 minutes to complete this training session.  When you have read through the material, you will be asked to answer 5 questions.

The information presented in this section is a summary of the hazards and controls for these compounds.  This is done for training purposes.  However, if you wish to get more detailed information, please consult the CHSP .

Flammable and combustible chemicals include flammable gases and liquids such as organic solvents, oils, greases, tars, oil base paints, and lacquers.  Flammable gases are discussed in Pub 3000 Chapters 7, Pressure Safety and Chapter 13, Gases.  The emphasis of this section is on flammable and combustible liquids. As a general rule, the lower the flash point of a liquid, the greater the fire and explosion hazard.  The flash point of a liquid is the minimum temperature at which it gives off sufficient vapor to form an ignitable mixture with the air near its surface or within its containment vessel. 

Flammable and combustible liquids are defined and divided into classes by the National Fire Protection Association based on their flash points:

Flammable Liquids (Class I):  Liquids having flash points below 100^oF (37.8^oC).

Combustible Liquids (Classes II and III):  Liquids having flash points at or above 100^oF (37.8^o C).

Control Measures

• Line managers shall evaluate use of flammables and combustibles in the work area to determine the extent of the hazard they present and to establish controls necessary to safeguard employee health.
• MSDSs and other hazard databases should be reviewed.
• An EH&S Industrial Hygienist may be contacted to provide guidance.

Selection and Use of Engineering Controls

• Use a fume hood or other appropriate exhaust ventilation when handling flammables and combustibles in a manner that may produce an airborne hazard. This includes transfer operations, preparation of mixtures, blending, sonification, spraying, and heating.

Storage

Detailed storage procedures and incompatibilities can be found in Storage Guidelines.  General guidelines are presented below:

• Use approved flammable storage cabinets.  If possible connect to exhaust ventilation.

• Do not store more than 60 gallons of flammable and combustible liquids in a storage cabinet.

• Ordinary domestic refrigerators must not be used for storing flammable liquids because they contain certain built-in ignition sources (such as electrical contacts).  These ignition sources may initiate a fire or an explosion if flammable vapors are present.Explosion proof refrigerators shall be used when cold storage is needed.  Contact Procurement for information on how to purchase an explosion proof refrigerator.

• Ensure that flammable and combustible liquids are segregated from oxidizers.

• Go to Specific Controls Exams
• Go to CHST Table of Contents