are used in
many workplaces. They may range from cleaning fluids, paints, and
gasoline to some more volatile and dangerous liquids.
The State Compensation Insurance Fund says that if
you remember a few simple, common sense rules when handling or
storing flammable liquids, you can help prevent injury to yourself
and your coworkers or prevent your jobsite from going up in flames.
Flammable liquids themselves will not burn, but as
the liquid evaporates, it gives off vapors that mix with the air to
form dangerous gases that can be set off by a small spark. Gasoline,
for example, evaporates at temperatures as low as 45º F below zero.
As the temperature rises, the rate of evaporation increases and more
and more vapors are given off. Vapors are usually heavier than air
so they collect in the lowest areas they can reach. Without good
ventilation to dissipate them, a small spark can set off a big
disaster.
Carefully read manufacturer’s labels on the
container of any flammable liquid before storing or using it.
Practice good housekeeping in flammable liquid storage areas. Clean
up spills immediately then place the cleanup rags in a closed,
bottom ventilated, metal container. Only use approved metal safety
containers or the original manufacturer’s container to store
flammable liquids.
Keep the containers closed when not in use; stored
away from exits or passageways. Don’t trust your nose to tell
you whether an area or container is vapor free. Not all dangerous
liquids give off vapors you can smell. Some vapors are poisonous as
well as flammable. Use flammable liquids only where there is plenty
of ventilation.
Be careful not to get a flammable liquid on you or
your clothing. It could cause painful skin irritation or ignite your
clothing and envelop you in flames. If you get it on you, wash it off
or change your clothes as soon as you can.
Keep flammable liquids away from any open flame
or spark and never smoke where flammable liquids are present. Treat
flammable liquids with respect and follow the manufacturer’s
suggestions for their use.
Many chemicals require special storage to
minimize serious risk for personal injury and damage to property and
equipment. Safe storage of chemicals begins with the identification
of chemicals to be stored and their hazards. Material safety data
sheets (MS-DSs) may not provide enough information for safe storage
and chemical segregation.
There are many published methods for storing
and separating chemicals into compatible families. Another resource
is the National Oceanic Atmospheric Administration (NOAA), which
has a “reactivity information” database for common hazardous
chemicals.
Flash Point
Flash point is the lowest temperature at which
a liquid can form an ignitable mixture (vapor) with air. Flammable
and combustible liquids vaporize and form flammable mixtures when
containers are left open, leaks or spills occur, or the liquids are
heated. Vapor mixed with air can ignite with exposure to a spark or
a flame.
The difference between a “flammable” and a
“combustible” liquid is the ease (temperature) with which the
substance burns or supports burning and is a measure of its
potential hazard. Flammable liquids form flammable vapors at
temperatures below 100° F (hot summer day). At normal room
temperatures, extremely flammable liquids form vapor below 73° F. A
combustible liquid is any liquid with a flash point greater than 100°
F but below 200° F.
The handling and use of flammable liquids and
their vapors may cause health hazards from ingestion, inhalation, or
skin contact. Health effects vary, depending on the particular
chemical, the chemical concentration, and route of exposure. Dangers
include toxcity, reactivity, instability, or corrosivity of the
material.
The ability of a chemical to either burn or
support burning is a potentially disastrous physical hazard.
Combustion byproduct contaminants are also a concern because they
are different from
those of
the original flammable material.
Byproducts include fumes, gases, smoke, and dust
particles. They can produce toxic effects, as in fire fatalities
resulting from poison gases. The storage of flammable substances
requires considerable care and thought to protect people and
property from fire and explosion. Inappropriate storage can result
in hazardous chemical interactions. Keep flammable materials away
from incompatible chemicals.
For example, the NIOSH Pocket guide identifies
turpentine as incompatible and reactive with strong oxidizers,
chlorine, chromic anhydride, stannic chloride, and chromyl chloride.
The following is a general guide for the storage and
segregation of flammables.
Do not store flammables with the following:
• Oxidizing agents, such as chlorates, nitrates,
perchlorates, permanganates and peroxides; they usually do not
combust on their own but provide the oxygen to accelerate the
combustion rate of other chemicals;
• Corrosive chemicals (acids or bases that
destructively attack organic and non-organic material) — Common
acids include sulfuric acid (battery acid), acetic acid, and
nitric acid. Although acetic acid and nitric acid are both acids,
they are incompatible and require further segregation. Common
alkalis (bases) include ammonium hydroxide, calcium oxide (lime),
and sodium hydroxide (lye).
• Materials susceptible to spontaneous heating
and/or explosions, hydrogen peroxide contacting combustible material
can result in spontaneous combustion. Picric acid can be explosive.
• Substances that react with air or moisture to
create heat. Sulfuric acid is a corrosive that reacts violently with
water, giving off an irritating and toxic fume. Avoid storing
flammables in direct sunlight or near other heat sources; eliminate
all sources of ignition. Keep the area dry and cool.
Use explosion-proof refrigerators designed for
chemical storage when chemicals require extra cool temperatures.
Most flammable vapors are heavier than air and settle low. Provide
adequate ventilation to prevent the accumulation of large amounts of
vapor.
Store flammable materials in a designated and
approved fire-proof cabinet. Cabinets must be labeled; FLAMMABLE –
KEEP FIRE AWAY. Metal cabinets must be constructed with at least
18-gauge sheet iron and double-walled, with 11⁄2 inch air space. The
doorsill must be at least two inches above the bottom of the
cabinet.
NFPA 30, Flammable and Combustible Liquids
Code, does not require venting for fire protection purposes. Vent
openings must be sealed according to manufacturer’s instructions.
However, if the cabinet is vented, it should be vented from the
bottom directly outdoors. Storage rooms have specific construction
and ventilation requirements; see 1910.106. Check local fire codes
for additional storage requirements.
Store flammable solids in fireproof storage
cabinets but not with flammable liquids. Flammable solids such as
sulfur, calcium carbide, and white phosphorus can ignite in the
presence of air or oxygen and continue to burn until the material is
spent.
Before storing flammables, ask the following:
• Is the inventory of flammables appropriate to
the workload?
• Does the quantity of in-use or stored
liquids outside of flammable storage cabinets or storage rooms
exceed 1910.106 requirements?
• Are containers closed and stored in
appropriate fireproof storage containers, cabinets, or rooms when
not in use?
• Are approved safety cans in use, and are they
in good condition?
• Are flammables stored with compatible
chemicals?
• Are flammable liquids stored in areas where
vapors cannot collect and away
from
electrical motors and other sources of ignition?
• Are containers labeled appropriately and
expiration dates observed?
• Are bonding and grounding provisions in place
for transfer of flammables?
• Are fire extinguishers available?
• Are there established procedures for the
cleanup of spills and the disposal of chemicals and clean-up
materials? FSM
