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SAFETY
AND LABORATORY RULES for ORGANIC & GENERAL CHEMISTRY LABORATORIES
Explanatory comments may be found below under
Standard Operating Procedures
- APPROVED SAFETY GOGGLES
MUST BE WORN AT ALL TIMES.
- NO FOOD, DRINKS OR SMOKING
ARE ALLOWED.
- SHOES MUST BE WORN. No bare
feet or thong sandals are allowed.
- WORK IS PERMITTED ONLY DURING SCHEDULED LABORATORY
PERIODS. Work is not permitted in other laboratory periods unless
space is available and written permission is obtained from your
instructor.
- NO OPEN FLAMES ARE ALLOWED
except as directed by the instructor.
- KNOW THE LOCATION OF FIRE
EXTINQUISHERS, SAFETY EQUIPMENT, AND THE NEAREST EXIT.
- NO UNAUTHORIZED EXPERIMENTS MAY BE PERFORMED.
- DO NOT USE BROKEN OR CRACKED GLASSWARE.
Check glassware before using it.
- NEVER TASTE OR SMELL CHEMICALS.
- AVOID CONTACT OF CHEMICALS
WITH SKIN. The use of rubber gloves is recommended.
- DISPOSE OF CHEMICAL WASTE
AS DIRECTED BY INSTRUCTOR.
- CLEAN YOUR WORK AREA AND
PUT AWAY ALL EQUIPMENT AND GLASSWARE BEFORE
LEAVING. Make sure equipment is put away in the correct locker
- your personal locker or the common locker.
- PUT PAPER TRASH AND BROKEN GLASS
IN LABLED TRASH CONTAINERS.
- KEEP INSTRUMENT ROOM CLEAN
AND FREE OF PAPER.
STANDARD OPERATING PROCEDURES
IN THE CHEMISTRY LABORATORY
Any student working in an
unsafe manner may be dismissed from the laboratory by an instructor.
ATTITUDE AND
PREPARATION
A. Come to laboratory
periods on time and mentally prepared by studying the experiment
and planning your activities.
B. Be prepared physically;
for example, don't try to do lab work on an empty stomach, or without
sleep.
C. Write everything
you do and see in your notebook so that you can trace your actions
and make corrections if necessary.
D. Wear sensible clothing,
including shoes that are comfortable and permit rapid movement in
case of emergency, and hair or hat that does not obstruct your view
or dangle into the experiment.
E. If you wear contact
lenses, try to avoid wearing them in the lab. If you must wear contact
lenses, your goggles must seal particularly well to your face.
F. If you injure yourself,
even slightly, report it to your instructor, who will direct you
to first aid. If you experience eye irritation, flush your eyes
at the nearest emergency eyewash station for 15 minutes (remove
contacts) and seek medical attention immediately.
G. If you have any
existing physical conditions that might affect your performance,
your health, or other peoples' health in the lab, please inform
your instructor. This information will be kept confidential; examples
might include pregnancy, medications, allergies, epilepsy, AIDS.
Special arrangements may be possible.
YOUR WORKING
ENVIRONMENT
A. GOGGLES meeting ANSI standard Z87.1-1979 for chemical splash
protection are required at all times in labs or instrument rooms,
i.e. all parts of the lab, even when your are not handling chemicals.
The goggles will protect your eyes from most splashes and impacts.
The goggles do not meet the standard if the air baffles are removed.
Some people have trouble with their goggles fogging up. The best
solution is to take a short break outside the lab to clean them.
B. Rubber gloves are strongly recommended to protect you from
absorption of chemicals through the skin. We also recommend a lab
coat to protect your clothes and skin from your and your neighbor's
spills.
C. Keeping
your bench space tidy will minimize breakage and spills of your
valuable products.
D. You are expected to clean up your own
mess in community areas such as the IR room.
E. Keep
your glassware and other equipment cleaned up as you work. Having
clean, dry glassware available at all times will save you much time
in the long run.
F. Be
careful not to contaminate reagents with your spatulas or droppers.
If you take too much of a reagent, give it to a needy neighbor -
do no return it to the bottle.
G. Do
not wander off with the only bottle of a reagent that everyone needs;
keep it in its assigned location.
H. Be
sure the aisles are passable.
GLASSWARE
A. The most common laboratory injury is a cut occurring upon
breakage of glass or porcelain. Most cuts can be prevented by careful
work which prevents breakage.
B. The safe procedure
for inserting a glass tube or thermometer into a stopper with a
hole is as follows:
I. Be sure the tip
of the tube is fire-polished.
II. Lubricate the
glass with glycerol or water.
III. Be sure the
hole in the stopper is large enough.
IV. Grasp the glass
about 1" (no farther) from the end and push and twist to insert
it into the stopper.
V. Be sure that the
hand holding the stopper is not in line with the entering glass.
VI. As the glass
begins to slide into the rubber, move the hand holding the glass
back a little, always keeping it no more than 1" from the rubber.
VII. Most accidents
occur because the glass snaps above the stopper from a force sideways
(torque). Keeping your hand close to the stopper will help prevent
your exerting a force sideways on the glass.
VIII. The above considerations apply also
to attaching rubber hoses to condensers. The condenser
should be in your hand (not clamped to an apparatus) and gripped
close to the lubricated connector being inserted into the hose.
C. Never use a thermometer as a stirrer!
Always support a thermometer in a beaker or flask with a clamp.
If a mercury thermometer breaks, immediately contact the laboratory
instructor and restrict access to the area of contamination until
cleanup can be arranged.
D. Round-bottomed flasks will not stand upright by themselves
and if rested on the counter will roll. They must be supported on
a cork ring, in (not on) a beaker, or in a clamp.
E. When glassware is assembled, care should
be taken to use the minimum number of clamps needed for support,
making sure:
I. The clamp is attached to a vertical
support bar.
II. No torque is applied by the clamp.
III. Top-heavy apparatus is prevented from rotating
and tipping.
IV. Hanging pieces are clamped - grease
will not hold them against the force of gravity!
F. Do not use a glass stopper to seal a hot
container or you may never get it out again. Cork is recommended
for organic solvents since rubber dissolves in organic solvents
and vice-versa.
G. Graduated cylinders are metastable and
tip easily with the touch of a sleeve.
H. Report breakage of glassware to your instructor
for disposal instructions.
I. Think before cleaning equipment - it makes
little sense to scrub a graduated cylinder that contained ether
or a water-insoluble material with soap and water.
SAFETY EQUIPTMENT
Your instructor will show
you where it is; remind yourself from time to time during the semester.
A. Fire Extinguishers for smothering
fires. TSU policy regarding response to fires restricts the use
of fire extinguishers to persons who are properly trained. Small
fires may be extinguished by covering with a book or larger container.
B. Fire Blanket for smothering fires.
C. Safety Shower for rinsing chemicals off
the body.
D. Eye Wash Fountain
for rinsing chemicals from the eyes.
E. First Aid Kit -
Note: even minor injuries must be reported to your instructor.
F. At least two exits.
G. Dustpan and broom for removing broken
glass.
H. Use Acetic Acid to neutralize a base spill.
Baking Soda (Sodium Bicarbonate) are to neutralized acid spill.
TOXIC HAZARDS
A. The materials used
in the chemistry lab are the safest we can find consistent with
your need to develop skills in working with hazardous materials
in your career in science.
B. Since you are wearing eye protection,
the opportunity for liquids or solids to enter the eye is small.
Chemicals in the eye should be immediately flushed with copious
amounts of water using the eyewash fountain.
C. To prevent inhalation of organic and inorganic
vapors, do your experiments in the fume hood or under the minihoods
on the bench.
D. If your need to determine the odor of
any material, waft it gently toward your nose with your hand - don't
stick your nose in the container and inhale.
E. Organic compounds can be absorbed through
the skin, so be careful about spilling things. Wear rubber gloves
to prevent contact with your skin, but treat the gloves as if they
were bare skin, keeping them scrupulously clean. You might set aside
a pen for laboratory work to minimize the possibility of contamination
from your gloves via your pen to your hands and face. Obviously,
chewing a pen or pencil that has been used in the lab would unwise.
F. Organic vapors also
can be absorbed into food or tobacco which you may ingest later.
Moreover, any drinks brought into the lab could have things spilled
into them. No food or drinks in the laboratory, not even stuffed
in your backpack. If you do not have a locker to keep food in, please
remove the food, drink and cigarettes to the hallway, or ask your
instructor for a safe place to keep it. Smoking is not allowed in
State buildings, as the nicotine and other contents of the smoke
are well-known health hazards (look up the LD50 of nicotine
if you are skeptical).
G. If you spill a liquid on the bench, immediately
soak it up with paper towels and, if it is volatile, transfer the
towels to the hood. Inform your instructor as to the nature of the
spill in case further action is warranted.
H. If concentrated
acid is spilled, add sodium carbonate or bicarbonate, solution or
solid. If concentrated base is spilled, add dilute and/or weak acid
(e.g. acetic). Indicator solution or paper will be available in
the lab. If your skin (or clothing) comes in contact with the spill,
immediately flush the skin or clothing with water for 15 minutes.
I. Should you spill bromine solution anywhere,
treat the spill immediately with sodium thiosulfate solution.
J. Bottles of the reagents mentioned in g)
and h) are available on the small counter above your bench.
HEAT HAZARDS
A. Most organic compounds are flammable and
may catch fire even in the absence of flame at high temperatures.
B. Flames are rarely allowed in the organic
laboratory. If flames are permitted by your instructor, plan your
experiments so that you never leave your
flame unattended.
C. If you light a flame,
you are responsible for the consequences, so check with your instructor
for a safe location.
D. If you use a bunsen burner, be sure to
tie back your hair and be careful that hair or clothing are kept
clear of the flame.
E. If there is a flame in the neighborhood,
do not pour flammables; organic vapors are usually denser than air
and will flow along the bench without alerting you by their odors.
F. Make sure you know the location of the
nearest fire extinguisher and the nearest exit.
G. Reactions that are exothermic or are being
heated must be monitored; do not leave them without having someone
watch.
H. Never, never, never
heat a closed system! Pressure will build up and cause the glass
to fail, sending projectiles of glass in all directions. Do not
depend on small leaks - a substantial air exit must be provided.
IF THERE IS A FIRE
A. In the lab where you are working.
I. Shout "fire" to alert your neighbors
and instructor if you discover it.
II. A small fire in a test tube or other
container can usually be extinguished by covering the container
with a watch glass or book. If the fire cannot be extinguished
by one extinguisher or by sand or water, you will be instructed
to evacuate, following the procedure in b).
III. One terrible possibility is that someone's
clothing is set on fire. If the person runs, the flame will be
increased by increasing the supply of oxygen. It must be smothered.
Wrap the person in a lab coat, fire blanket, or whatever is handy
to exclude oxygen.
B. Elsewhere in the building (fire alarm
sounds):
I. Extinguish any flames and turn off electrical
equipment.
II. Close any open windows and internal
doors near you.
III. Walk
quickly through the nearest exit to the hallway and leave the
building by the nearest stairwell.
IV. The last person leaving the room, usually
your instructor, will close the hall door.
LABORATORY ELECTRICAL EQUIPTMENT
A. During the semester you will use a variety of instruments
to analyze your samples. As with all electrical equipment, a certain
amount of care is needed to prevent fire, shock and damage to the
equipment. Be careful not to bring water, especially on your hands,
into contact with connected electrical equipment.
B. The hot plates you are provided are powerful
and seldom need to be set higher than 3.
C. Much of the heating in organic chemistry
is done with electrical heating mantles; these must be plugged into
a variable transformer, not
directly into the outlet or they will overheat and may cause a fire.
D. Never transfer anything into a flask that
is sitting in a heating mantle; use a cork ring, beaker or clamp
to hold the flask during transfers. Organics spilled in a mantle
will catch on fire when the electricity is connected, acids or bases
will corrode the wires, and water will cause a short circuit.
E. Never pour into a container on an electronic
balance - they often have the wiring and knife edge under the pan
are thus easily damaged.
F. Turn off electrical equipment immediately
after you have finished unless your instructor has stated otherwise
(e.g. the gas chromatographs must be left on for an hour to stabilize).
G. Report frayed cords,
or non-functional equipment to your instructor. Do
not put it back in the cupboard or you will be stuck
with it again next time.
H. No samples are allowed
on top of any instruments.
PRESSURE HAZARDS
A. Never
heat a closed system.
B. When using a separatory
funnel, vent frequently and remove the stopper immediately upon
setting it upright for separation.
C. Compressed gas cylinders must be strapped
to the bench above their center of gravity when the protective caps
are off. Pressure regulators are generally not interchangeable between
gases for safety reasons. Gas cylinders should be free of regulators
and protected by their cap before moving.
WASTE DISPOSAL
A. In order to minimize damage to the environment,
and in compliance with State and Federal law, chemical wastes must
be separated into categories and carefully labelled as to their
contents. Please read and follow the labels on the waste bottles
to ensure that your chemical wastes are treated safely and appropriately.
You will find containers for:
I. General Organic Waste (flammable)
II. Halogenated Hydrocarbons (non-flammable)
III. Chromic Acid Solutions (these have been phased
out)
IV. Lead
V. Silver
VI. Other Heavy Metals
VII. Waste from specific experiments in some cases.
VIII. Acids
IX. Bases
X. In some experiments, acids and bases will be
neutralized to a pH of 6 - 10 (State law) as part of the experiment
and flushed down the drain with lots of water. Your instructor
will give you instructions in particular cases. Indicator solution
or paper will be available in the lab.
XI. Broken thermometers create the special problem
of spilled mercury (a toxic heavy metal). Report such accidents
immediately to your instructor; usually any mercury which cannot
be collected is reacted with sulfur or absorbed with a special
kit before disposal as heavy metal waste.
XII. Broken glass or porcelain is swept up into
a dust pan and disposed of in a special container for broken glass.
Please don't use your fingers.
Drafted by Dr. L. M. Sweeting 1989, Updated Sept.
2001 PNT
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