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Environmental and Workplace Health

Flammable and Combustible Liquids

2006
ISBN: 0-662-36779-0
Cat. No.: H46-2/04-350E

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Common combustible liquids are: diesel fuel,kerosene.
Common flammable liquids are: gasoline,turpentine,acetone.

Flammable liquids give off vapour that can easily be ignited at normal working temperatures. A combustible liquid does not catch fire as easily as a flammable liquid.Under WHMIS,a flammable liquid has a flash point*under 37.8 ° C (100 ° F). A combustible liquid has a flash point,above normal workng temperature,from 37.8 to 93.3 ° C (100 to 200 ° F).

Glossary of Terms

Flammable / Combustible

Flash Point The lowest temperature at which a liquid "burns". At the flash point the liquid gives off enough vapour to form a flammable air-vapour mixture near its surface.
Lower Explosive Limit (LEL) The lowest concentration of vapour in air that will burn or explode upon contact with a source of ignition. Ignition Source(s) Common ignition sources include sparks, flames,friction,and hot surfaces."Hidden"sources include static electricity,light switches,and other electrical devices such as power tools.

Hazards of Flammable/Combustible Liquids

Fire or Explosion - A fire/explosion requires fuel (such as flammable vapour),air,and an ignition source*.

Remember there are many hidden ignition sources. Always assume there are ignition sources around you.

The best protection from fire/explosion is to minimize the amount of flammable vapour and mists released into the workplace air in order to prevent the buildup of a flammable atmosphere.

Combustible liquids used in high temperature processes can be as hazardous as flammable liquids.

Other Hazards - Even if you are working well below the lower explosive limit (LEL)*,remember that many of these liquids can also pose health hazards and be reactive.

Working Safely with Flammable Materials

CONSULT the Material Safety Data Sheet (MSDS) for information about the hazards and necessary precautions for the materials you are using.

PREVENT the release of flammable vapours and mists into the workplace air to minimize fire/explosion risk.

USE only in well-ventilated areas.

KEEP containers closed.

USE the smallest amount of flammable liquid necessary in the work area.

CLEAN up spills immediately.

USE non-sparking ventilation systems and equipment.

GROUND all metal drums,transfer vessels,hoses and piping to prevent buildup of static charge.Ground clips must contact bare metal.

USE only containers and dispensing equipment (faucet, pump,drip can)that are approved for use with flammable liquids.

PRACTICE good housekeeping by keeping areas clear of materials that can burn.

REPORT leaks,spills and ventilation failures to your supervisor immediately.

UNDERSTAND and PRACTICE emergency procedures so that you know what to do if it becomes necessary.

DO NOT HEAT containers or distribution systems containing flammable or combustible liquids.

DO NOT USE flammable or combustible liquids for anything other than their intended uses.

In the event of an emergency...

Warn people in the area and move to a safe location to call for emergency help.

For additional information and resources visit www.whmis.gc.ca and/or www.ccohs.ca