Chemical Hygiene Plan - Queensborough Community College ...

• Metal Picrate Salts
• 2,4-Dinitrophenylhydrazine (dry)
• Benzoyl peroxide (dry)
• Metal Perchlorate Salts
7.2 Flammable and Combustible Liquids
The OSHA Laboratory Standard defines a flammable liquid as any liquid having a flashpoint
below 100 degrees F (37.8 degrees C), except any mixture having components with flashpoints
of 100 degrees F (37.8 degrees C) or higher, the total of which make up 99% or more of the total
volume of the mixture.
Flashpoint is defined as the minimum temperature at which a liquid gives off enough vapor to
ignite in the presence of an ignition source. The risk of a fire requires that the temperature be
above the flashpoint and the airborne concentration be in the flammable range above the Lower
Explosive Limit (LEL) and below the Upper Explosive Limit (UEL).
The OSHA Laboratory Standard defines a combustible liquid as any liquid having a flashpoint
at or above 100 degrees F (37.8 degrees C), but below 200 degrees F (93.3 degrees C), except
any mixture having components with flashpoints of 200 degrees F (93.3 degrees C), or higher,
the total volume of which make up 99% or more of the total volume of the mixture. OSHA
further breaks down flammables into Class I liquids, and combustibles into Class II and Class III
liquids. Please note this classification is different than the criteria used for DOT classification.
This distinction is important because allowable container sizes and storage amounts are based on
the particular OSHA Class of the flammable liquid.
Classification Flash Point Boiling Point
Flammable Liquid
Class IA =100 degrees F, =140 degrees F, < 200 degrees F --
Class IIIB >=200 degrees F --
Under the Department of Transportation (DOT) hazard class system, flammable liquids are listed
as hazard class 3.
Flammable and combustible liquids are commonly used at QCC and are important in a number
of laboratory processes. However, in addition to the flammable hazard, some flammable liquids
also may possess other hazards such as being toxic and/or corrosive.
When using flammable liquids, keep containers away from open flames; it is best to use heating
sources such as steam baths, water baths, oil baths, and heating mantels. Never use a heat gun to
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