Transcript Flammable and Combustible Liquids

Flammable and Combustible
Liquids
by Environmental, Health
and Safety Services
Lacquer
thinner
Isopropyl
alcohol
Acetone
Overview
Gasoline
Toluene
• Definitions
• Classes of Liquids
• Precautions
• Storage Requirements
• Preventive Measures
Methyl formate
Kerosene
Diethyl
ether
Ethyl ether
MEK
Flammable Liquids
• Flammable liquids can cause a fire or
explosion, and like many other
substances, they can also cause
serious health effects from
overexposure.
3
Note: On the NFPA diamond label, a
fire hazard rating of 3 or 4 denotes a
flammable liquid.
Flammable Liquids
• A flammable liquid is any liquid having a
flashpoint below 100°F.
– Exception: Any mixture having
components with flashpoints of 100°F or
higher, the total of which make up 99% or
more of the total volume of the mixture.
Note: The flash point is the lowest temperature at which
a liquid gives off enough vapor to form a flammable
mixture with air.
Flammable Liquids
• The vapors of flammable liquids often
present the most serious hazard.
– The vapors can easily
ignite or explode.
– Flammable liquid vapors
are heavier than air and
may settle in low spots, or
move a significant
distance from the liquid
itself.
Explosive Limits
• The explosive concentration of vapors
in air has a lower and upper limit.
– The Lower Explosive Limit (LEL) is the
lowest concentration that will ignite.
– The Upper Explosive Limit (UEL) is the
highest concentration that will ignite.
– If the vapor concentration is between the
LEL and UEL, there is serious risk of fire or
explosion.
Explosive Limits
Above the Upper Explosive Limit, the mixture is too rich to burn
UPPER EXPLOSIVE LIMIT
Explosive Range
LOWER EXPLOSIVE LIMIT
Below the Lower Explosive Limit, the mixture is too lean to burn
Classification
• Flammable and
combustible liquids are
classified according to
their flashpoints.
This is important to know
because the quantity of
flammable/combustible liquids
that can be stored in any one
location is determined by the
class of the liquid.
Flammable Liquids
Class 1A
Class 1B
Class 1C
Liquids having flashpoints below
73°F and having a boiling point
below 100°F.
Liquids having flashpoints below
73°F and having a boiling point at or
above 100°F.
Liquids have flashpoints at or above
73°F and below 100°F.
Combustible Liquids
• A combustible liquid is any liquid having
a flashpoint at or above 100°F.
Note: Check your Material Safety Data Sheet
(MSDS) sheet for the characteristics or classification
of a particular liquid.
Combustible Liquids
Class II
Liquids with flashpoints at or above
100°F and below 140°F.
Class III
Liquids with flashpoints at or above
140°F
Class IIIA
Those with flashpoints at or above
140°F and below 200°F.
Class IIIB
Those with flashpoints at or above
200°F.
Area Exempt Amounts
• There are certain amounts of flammable
and combustible liquids stored in each
control area that are considered exempt.
– If these amounts are exceeded, then the area
or building may have to be reclassified as a
Hazardous Use Group under the building
code.
Excessive storage is a
serious violation of the
fire code!
Contact the EHSS Fire Safety Engineer at 231-9198
for assistance, if necessary.
Storage Areas
• Flammables should be stored in an approved
cabinet in a cool, well ventilated area to avoid
pressure buildup and vaporization.
Storage Areas
• There should be at least one
fire extinguisher in the area.
– Large storage areas should
have a fire protection system
installed and must be approved
for this use.
Storage Cabinets
• Use flammable liquid storage cabinets
where greater quantities of liquids are
needed.
Contrary to popular belief, these cabinets
are not designed to contain a fire, but to
prevent an outside fire from reaching the
contents for a period of 10 minutes –
enough time to evacuate the area.
Flammable Liquid Exempt
Amounts (in gallons)
Condition
IA
IB
IC
Inside; unprotected by
sprinklers or cabinets.
30
60
90
Within approved cabinet;
unsprinklered structure.
Not in approved cabinet;
sprinklered structure.
In approved cabinet;
sprinklered structure.
Outside storage.
60
120
180
60
120
180
120
240
360
60
120
180
Combustible Liquid Exempt
Amounts (in gallons)
Condition
II
IIIA
IIIB
Inside; unprotected by
sprinklers or cabinets.
120
330
13,200
Within approved cabinet;
unsprinklered structure.
Not in approved cabinet;
sprinklered structure.
In approved cabinet;
sprinklered structure.
Outside storage.
240
660
26,400
240
660
unlimited
480
240
1,320 unlimited
660
unlimited
Limitations on Storage
The maximum storage of
flammables and combustibles
in any one area under the
Virginia Fire Prevention Code is
60 gallons of flammables and
120 gallons of combustibles.
These quantities must be in an approved storage area, i.e. a
flammables cabinet or other acceptable means.
There are also limitations on
quantities stored in individual
containers.
Storage Containers
• Containers should be tightly sealed when
not in use.
• Approved safety cans are recommended
for smaller quantities.
– The spring-loaded safety cap
prevents spillage, prevents
vapors from escaping, acts as a
pressure vent if engulfed in fire,
prevents explosions and
rocketing of the can!
Flammable Liquid Limitations
(in gallons)
Container
Glass or approved plastic
IA
IB
1 pt. 1 qt.
IC
1
Metal (other than DOT drum)
1
5
5
Safety cans
2
5
5
60
60
60
660
660
660
Metal drums (DOT specifications)
Approved portable tanks
Combustible Liquid Limitations
(in gallons)
Container
II
III
Glass or approved plastic
1
1
Metal (other than DOT drums)
5
5
Safety Cans
5
5
Metal drums (DOT specifications)
60
60
Approved portable tanks
660
660
Precautions
• The unsafe use, storage,
dispensing, or disposal of
flammable materials can be
a prime source of fires and
explosions.
– Read labels of all spray cans
to identify those with
flammable gas-propellants.
Ex. Butane and Propane
Precautions
• Some flammable liquids have a tendency
to accumulate a static electric charge,
which can release a spark that ignites
the liquid.
– Always bond metal dispensing and
receiving containers together before
pouring.
Precautions
• To bond containers, each
container is wired together and
one container is connected to a
good ground point to allow any
charge to drain away safely.
– Because there is no easy way to
bond plastic containers, their use
should be limited to smaller sizes
(no more than 4L).
Precautions
• Overexposure to flammable
liquids may present health
hazards.
• Consult the Material Safety
Data Sheet (MSDS) on the
material you will be using to
identify health hazards and
protective measures to be
taken.
Precautions
• Effects of overexposure to flammable
liquids includes:
– Inhalation: Irritation to respiratory
passages, nausea, headaches, muscle
weakness, drowsiness, loss of
coordination, disorientation, confusion,
unconsciousness, and death.
Precautions
– Skin Contact: irritated, dry, cracked skin,
rashes, dermatitis.
– Eye Contact: burning, irritation, eye
damage.
– Ingestion: irritated digestive tract,
poisoning, death.
Preventive Measures
• Quantities of flammable and combustible
liquids located outside of storage
cabinets should be restricted to one day’s
supply, or to what can be used during a
single shift.
– If possible, substitute nonflammable, nonhazardous materials for flammable liquids.
Preventive Measures
• To prevent the accumulation
of vapors inside of storage
areas, a continuous
mechanical ventilation
system must be in place.
Preventive Measures
• All nonessential ignition sources must
be eliminated where flammable liquids
are used or stored.
– Common ignition sources include:
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Open flames from cutting and welding
Furnaces, matches, heaters, smoking materials
Static electricity, friction sparks
Motors, switches, circuit breakers
Preventive Measures
• Materials that contribute to a flammable
liquid fire should not be stored with
flammable liquids. For example,
– Oxidizers
– Organic peroxides
Preventive Measures
• If a spill occurs:
– Limit spread by diking with suitable absorbent
material.
– Minimize vapors by covering surface of spill
with same absorbent material.
– Ensure all sources of ignition are off or
controlled.
– Notify your supervisor immediately and call
911 if necessary.
Preventive Measures
• If a spill occurs:
– Begin cleanup right away.
• Sweep saturated absorbent material into a
dustpan.
• Place material into a metal container with a tight
fitting lid.
• Place any saturated rags or cloths into the same
container.
• Contact EHSS at 231-2982 for pickup and proper
disposal.
Preventive Measures
• Always check the labels of containers
(or the MSDS) for recommended
personal protective equipment to be
worn.
– Lab coats
– Splash aprons
– Eyewear
– Gloves
– Overboots
Summary
• Careless mistakes and safety shortcuts
lead to serious problems when it comes
to flammable liquids.
• Respect flammable liquids
and their dangers - their
hazards are deadly…
Contact Information
• Environmental, Health and Safety
Services
– www.ehss.vt.edu
– 231-5985
• Fire Safety
– [email protected]
– 231-9198