ASTM formerly American Society for Testing and Materials publishes open and closed cup test procedures [, 6] for repeatable flashpoint measurements; the value will vary considerably with conditions. NFPA [1] includes the following definitions:. Autoignition temperature: The lowest temperature at which combustion material ignites in air without a spark of flame. For more information about the variation in the minimum autoignition temperature measured using small variations in conditions, click here.
Fire point is the lowest temperature at which a material can produce vapors fast enough to support continuous combustion [4, ]. A small spill can cover a large area of workbench or floor. Burning liquids can flow under doors, down stairs and even into neighbouring buildings, spreading fire widely. Materials like wood, cardboard and cloth can easily absorb flammable and combustible liquids.
Even after a spill has been cleaned up, a dangerous amount of liquid could still remain in surrounding materials or clothing, giving off hazardous vapours. Vapours can flow from open liquid containers. The vapours from nearly all flammable and combustible liquids are heavier than air.
If ventilation is inadequate, these vapours can settle and collect in low areas like sumps, sewers, pits, trenches and basements. The vapour trail can spread far from the liquid. If this vapour trail contacts an ignition source, the fire produced can flash back or travel back to the liquid. Flashback and fire can happen even if the liquid giving off the vapour and the ignition source are hundreds of feet or several floors apart.
The most obvious harm would be the danger of a fire or explosion. After the immediate danger of a fire, there are sometimes other properties of these liquids that may be hazardous to the body.
Some flammable and combustible liquids are corrosive. Many undergo dangerous chemical reactions if they contact incompatible chemicals such as oxidizing materials, or if they are stored improperly. The Material Safety Data Sheet and the supplier's labels on the containers should tell you about all the hazards for the flammable and combustible liquids that you work with. An example is 2-propanol also known as: dimethylcarbinol, isopropanol, or isopropyl alcohol.
It is a colourless liquid with a sharp odour like rubbing alcohol or resembling that of a mixture of ethanol and acetone.
It is flammable liquid and vapour. Vapour is heavier than air and may spread long distances. Distant ignition and flashback are possible. It is also considered to be a mild central nervous system depressant. High vapour may cause headache, nausea, dizziness, drowsiness, incoordination, and confusion.
It may also be irritating to the respiratory tract or eyes. Gasoline Safety Never use gasoline around a flame source. Be particularly aware of sources such as matches, lighters, cigarettes and pilot lights on stoves and water heaters or in well-ventilated areas Start charcoal grills with fuels labeled as charcoal starter fluid— never use gasoline. Fill the tanks prior to use. Refuel with the engine turned off and cool. Running engines on gasoline-powered equipment such as mowers can spark and cause ignition of the gasoline.
If you are transporting gasoline in a car, keep the container in the trunk and keep the trunk lid ajar for ventilation. Never siphon gasoline by mouth. It can be fatal if swallowed. Always keep the minimum amount of gas required generally no more than a gallon.
0コメント