LABORATORY SAFETY While working in the science laboratory, you
will have certain important responsibilities that do not apply to
other classrooms. You will be working with materials and apparatus
which, if handled carelessly or improperly, have the potential to
cause injury or discomfort to someone else as well as
yourself.
NFPA CHEMICAL HAZARD LABEL 2 3 4 0 Least Serious 4 Most Serious
40 Flammable vapor which burns readily Substance is stable
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NFPA CHEMICAL HAZARD LABEL Avoid water. May detonate with heat
or ignition. Severe health risk. Burns readily. Diborane 4 34
W
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Health Hazard 4 Very short exposure could cause death or
serious residual injury even though prompt medical attention was
given. 3 Short exposure could cause serious temporary or residual
injury even though prompt medical attention was given. 2 Intense or
continued exposure could cause temporary incapacitation or possible
residual injury unless prompt medical attention is given. 1
Exposure could cause irritation but only minor residual injury even
if no treatment is given.irritation 0 Exposure under fire
conditions would offer no hazard beyond that of ordinary
combustible materials.combustible
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FLAMMABILITY 4 Will rapidly or completely vaporize at normal
pressure and temperature, or is readily dispersed in air and will
burn readily.normal pressure and temperatureair 3 Liquids and
solids that can be ignited under almost all ambient conditions. 2
Must be moderately heated or exposed to relatively high temperature
before ignition can occur. 1 Must be preheated before ignition can
occur. 0 Materials that will not burn.
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INSTABILITY 1 1 4 Readily capable of detonation or of explosive
decomposition or reaction at normal temperatures and
pressures.explosivedecompositionnormal temperatures and pressures 3
Capable of detonation or explosive reaction, but requires a strong
initiating source or must be heated under confinement before
initiation, or reacts explosively with water.explosivereacts
explosively with water 2 Normally unstable and readily undergo
violent decomposition but do not detonate. Also: may react
violently with water or may form potentially explosive mixtures
with water.decompositionreact violently with waterexplosivemixtures
1 Normally stable, but can become unstable at elevated temperatures
and pressures or may react with water with some release of energy,
but not violently.react with water with some release of energy 0
Normally stable, even under fire exposure conditions, and are not
reactive with water. 1 Prior to 1996, this section was titled
"Reactivity". The name was changed because many people did not
understand the distinction between a "reactive hazard" and the
"chemical reactivity" of the material. The numeric ratings and
their meanings remain unchanged.
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OX This denotes an oxidizer, a chemical which can greatly
increase the rate of combustion/fire.oxidizerchemicalcombustion
Unusual reactivity with waterUnusual reactivity with water. This
indicates a potential hazard using water to fight a fire involving
this material. This section is used to denote special hazards.
There are only two NFPA 704 approved symbols
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ACID This indicates that the material is an acid, a corrosive
material that has a pH lower than 7.0acidcorrosive materialpH ALK
This denotes an alkaline material, also called a base. These
caustic materials have a pH greater than 7.0basepH This denotes a
material that is corrosive (it could be either an acid or a
base).corrosive The skull and crossbones is used to denote a poison
or highly toxic material.poisonhighly toxic The international
symbol for radioactivity is used to denote radioactive hazards;
radioactive materials are extremely hazardous when inhaled.inhaled
Indicates an explosive material.explosive
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Laboratory Equipment
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1. Beaker Beakers hold solids or liquids that will not release
gases when reacted, or are unlikely to splatter if stirred or
heated. Very poor to measure volume with (+/-5%) accuracy Note the
size capacity (250 mL in this case)
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2. Erlenmeyer Flask Erlenmeyer flasks hold solids or liquids
that may release gases during a reaction or that are likely to
splatter if stirred or heated. Note the size
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3. Florence Flask Rarely used in first year chemistry, it is
used for the mixing of chemicals. Narrow neck prevents splash
exposure.
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4. Graduated Cylinder A graduated cylinder is used to measure
volumes of liquids probably your best everyday measuring tool. Note
the rubber bumpers, and also the size. Others that are smaller may
not have bumpers, but have reinforced glass.
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5. Test Tubes 18 x 150 mm 13 x 100 mm Ignition Tube (25 x 200
mm) Test tubes are used to mix chemicals, and also to heat
chemicals.
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6. Test Tube Holder A test tube holder is useful for holding a
test tube which is too hot to handle. Knowing where to hold this
piece of equipment is important.
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7. Test Tube Brushes Test tube brushes are used to clean test
tubes and graduated cylinders. Forcing a large brush into a small
test tube will often break the tube. Dont worry about drying the
inside of a test tube. Small test tube brush Large test tube
brush
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8. Test Tube Racks Test tube racks are for holding and
organizing test tubes on the laboratory counter.
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9. Rubber Stoppers Rubber stoppers (also cork) are used to
close containers to avoid spillage or contamination. Containers
should never be heated when there is a stopper in place.
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10. Well Plates Well plates are used when we want to perform
many small scale reactions at one time. It is like having lots of
test tubes available at one time.
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11. Watch Glass A watch glass is used to hold a small amount of
solid, such as the product of a reaction. Can also be used as a
cover for an evaporating dish or beaker.
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12. Stirring Rod The stirring rod is used to: a) manually stir
solutions; b) assist in pouring liquids; and c) to transfer a
single drop of a solution. Rubber policeman tip is used to remove
precipitates. Stir with this end.
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13. Dropper Pipet A dropper pipet is used to transfer a small
volume of liquid, usually one drop at a time. On top of each
dropper is a rubber bulb never put your mouth on the dropper to
provide suction
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14. Funnel A funnel is used to aid in the transfer of liquids
from one vessel to another, and will hold filter paper while
filtering.
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15. Graduated Pipet A graduated pipet measures and delivers
exact volumes of liquids uses a rubber bulb for suction (not your
mouth).
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16. Wash Bottle A wash bottle has a spout that delivers a water
stream to a specific area. Distilled water is the only liquid that
should be used in a wash bottle During use, keep the bottle upright
as shown, since ours have a tube that goes to the bottom of the
bottle. Distilled Water
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17.Electronic Balance Electronic balances are very accurate,
highly dependable, and rugged. The digital display makes the mass
value very easy to determine. On button Off button Tare button
Place item here to mass
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18.Spatula Spatulas are used to dispense solid chemicals from
their containers. Chemicals should never be transferred with your
bare hands.
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19.Beaker Tongs Beaker tongs are used to move beakers
containing hot liquids. Note the rubber coating to improve grip on
the glass beaker - do not hold this in a burner flame.
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20.Burner Burners are used for the heating of nonvolatile
liquids and solids. Hot plates will be used to gently heat any
flammable chemicals.
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21. Evaporating Dish The evaporating dish is used for heating
stable solid compounds and elements, as well as for evaporating
nonvolatile solutions.
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22. Crucible and cover Crucibles are used for heating certain
solids, particularly metals, to very high temperatures. The cover
can be used to contain any smoke particles.
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23. Clay Triangle The clay triangle is used as a support for
crucibles when being heated over a lab burner. It can also be used
to support a funnel when filtering.
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24. Crucible Tongs For handling hot crucibles; also used to
pick up other hot objects - NOT to be used for picking up
beakers!
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25. Ringstands Ringstands are a safe and convenient way to
perform reactions that require heating using a lab burner. Can also
be used as an insulating pad to place hot objects while they
cool.
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Ringstands and their components 26. Ring Clamp Ring clamps
connect to a ringstand, and provide a stable, elevated platform for
a beaker to be heated. Will also hold a clay triangle and funnel
during filtering.
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Ringstands and their Components 27. Test tube Clamps Test tube
clamps are used to secure test tubes, distillation columns, and
burets to the ringstand.
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Ringstands and their Components 28. Double Buret Clamps Double
Buret clamps are used to secure burets (long graduated tubes used
in titrations) to the ringstand.
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Ringstands and their Components 29. Wire Gauze Wire gauze sits
on the iron ring to provide a place to stand a beaker. On older
wire gauze, the white material was asbestos currently it is a
ceramic.
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30. Lighter These strikers are used to light lab burners. The
flints on strikers are expensive. Do not operate the striker
repeatedly just to see the sparks!
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31. Weighing Paper Used to measure small amount of solids.
Never place chemicals directly onto the balance.
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32. Hot Plates Used to gently heat liquids. We cant regulate
the heat In ours. To avoid spills, remove beaker or flask using
tongs and place it on the lab desk.
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33. Triple Beam Balance Used for weighing solids, liquids and
powders.
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34. Mortar and pestle Used to grind solids into powders
