Safety - Teach.Chem

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Transcript Safety - Teach.Chem

Safety
Basic Safety Rules
Use common sense.
No unauthorized experiments.
No horseplay.
Handle chemicals/glassware with respect.
Safety Features of the Lab
safety shower
fire blanket
fire extinguisher
eye wash
fume hood
circuit breaker switch
Government Regulation of Chemicals
The government regulates chemicals to reduce
the risk to the…
• Consumer
FDA, USDA, Consumer Product Safety Commission
• Worker
OSHA
• Environment
EPA
Chemical Stewardship
Government
Regulation
worker
OSHA
environment
EPA
The government
regulates chemicals
to protect the…
FDA
USDA
FAA
CPSC consumer
Thalidomide
• Prescription drug for morning sickness
• Drug can be made in two ways
– Put together same material in more than one way.
• A = “good” drug (stops morning sickness)
• B = “bad” drug (birth defects)
• Side-effect from “bad” drug
– Stopped development in fetus
• Short arms; “flipper-babies”
“Happy” & “Sad” Balls
• Cis-isomer
– Sad ball
• Trans-isomer
– Happy ball
Mercury Poisoning
One tiny drop of mercury shatters lives and science
Karen Wetterhahn, a chemistry
Professor at Dartmouth College,
died of mercury poisoning after
spilling just one drop in a laboratory on Aug. 14, 1996. The
mercury penetrated her skin
through gloves.
LYME, N.H. (AP) — It was just a drop of liquid,
just a tiny glistening drop. It glided over her glove
like a jewel.
Scientist Karen Wetterhahn knew the risks: The
bad stuff kills if you get too close.
She took all the precautions working with mercury in her Dartmouth College lab — wearing protective gloves and eye goggles, working under a
ventilated hood that sucks up chemical fumes.
So on that sunny day in August, when she accidentally spilled a drop, she didn't think anything of
it. She washed her hands, cleaned her instruments
and went home.
It was just a drop of liquid, just a tiny glistening
drop.
At first, friends thought she had caught a stomach
bug on her trip to Malaysia. It wasn't until she
started bumping into doors that her husband, Leon
Webb, began to worry. Karen, always so focused,
always so sure of her next step, was suddenly falling
down as if she were drunk.
In 15 years together, she had never been sick, never stopped working, never complained. Leon was
stunned when she called for a ride home from work.
Over lunch a few days later, Karen confided to her
best friend, Cathy Johnson, that she hadn't felt right
for some time. Words seemed to be getting stuck in
her throat. Her hands tingled. It felt like her whole
body was moving in slow motion.
"Karen," Johnson said as she drove her back to
the college, "we've got to get you to the hospital."
"After work," Karen promised, walking unsteadily into the Burke chemistry building for the last
time.
That night, Leon drove her to the emergency
room. It was Monday, Jan. 20, 1997, five months
since she had spilled the drop in the lab.
Just a single drop of liquid. Yet somehow it had
penetrated her skin.
By the weekend, Karen couldn't walk, her speech
was slurred and her hands trembled. Leon paced the
house. "Virus" seemed an awfully vague diagnosis,
for symptoms that were getting worse every day.
"It's mercury poisoning," Dr. David Nierenberg
said. "We have to start treatment immediately."
Leon hung up with relief. At last, they understood
the problem. Now maybe they could fix it.
It seemed impossible to believe that anything
could be wrong with Karen Wetterhahn, one of
those quietly impressive individuals whose lives
seemed charmed from the start.
Serious and hardworking, she excelled at every thing she turned to — science or sailing or skiing.
She grew up near Lake Champlain in upstate New
York in a family so close that when she and her only
sister became mothers, they named their daughters
after each other: Charlotte and Karen.
Karen was always the brilliant one of the family,
the one who would do great things. And she did, becoming the first woman chemistry professor at
Dartmouth, running a world-renowned laboratory
on chromium research, devoting herself to her
work.
It was important work, the kind that could lead to
cures for cancer and AIDS. Karen thrived on it. She
loved nothing more than experimenting with a
chemical, figuring out its bad side and how it breaks
down living things.
Lead Poisoning
(Plumbism)
LD50 =
mg / kg
Small children may accidentally
ingest lead-based paints that peel
off from window sills and walls.
Lead accumulates near bone joints
– lighter color on X-ray is lead.
Effects: slow mental development,
lack of concentration
Safety Symbols
SAFETY CLOTHING
This symbol is to remind you to wear a
laboratory apron over your street clothes to
protect your skin and clothing from spills.
SAFETY GOGGLES
This symbol is to remind you that safety
goggles are to worn at all times when
working in the laboratory. For some
activities, your teacher may also instruct
you to wear protective gloves.
GLOVES
This symbol is to remind you to wear gloves
to protect your hands from contact with
corrosive substances, broken glass, or
hot objects.
HEATING
This symbol indicates that you should be
careful not to touch hot objects with your
bare hands. Use either tongs or heat-proof
gloves to pick up hot objects..
FIRE
This symbol indicates the presence of an
open flame. Loose hair should be tied back
or covered, and bulky or loose clothing
should be secured in some manner.
DANGEROUS VAPORS
This symbol indicates the presence of or
production of poisonous or noxious vapors.
Use the fume hood when directed to do so.
Care should be taken not to inhale vapors
directly. When testing an odor, use a wafting
motion to direct the vapor toward your nose.
EXPLOSION
This symbol indicates that the potential for
an explosive situation is present. When you
see this symbol, read the instructions carefully and follow them exactly..
POISON
This symbol indicates the presence of a poisonous substance. Do not let such a substance
come in contact with your skin and do not
inhale its vapors.
ELECTRICAL SHOCK
This symbol indicates that the potential for
an electrical shock exists. Read all instructions
carefully. Disconnect all apparatus when
not in use.
RADIATION
This symbol indicates a radioactive substance.
Follow your teacher's instructions as to
proper handling of such substances..
CORROSIVE SUBSTANCE
This symbol indicates a caustic or corrosive
substance - most frequently an acid.
Avoid contact with skin, eyes, and clothing.
Do not inhale vapors.
DISPOSAL
This symbol indicates that a chemical should
be disposed of in a special way. Dispose of
these chemicals as directed by your teacher.
BREAKAGE
This symbol indicates an activity in which
the likelihood of breakage is greater than
usual, such as working with glass tubing,
funnels and so forth.
HYGIENE
This symbol is to remind you to always
wash your hands after completing a laboratory investigation. Never touch your face
or eyes during a laboratory investigation.
Safety Symbols
Eye
Protection
Required
Heat
Protection
Clothing
Protection
Required
Glassware
Safety
Hand
Protection
Required
Laboratory
Hygiene
Chemical
Safety
Sharp
Object
Hazard
Caustic
Substance
Waste
Disposal
Safety Equipment
Safety Goggles
Fire Extinguisher
Type A
Type B
Type C
Safety Shower
Chemical Burns
Flammable
Health
Reactive
Special
Chemical burns on feet.
Skin burned by chemicals
DANGER
Laboratory
Safety Rules
SAFETY in the Science
Classroom
Obey the safety contract
– Use common sense
– No unauthorized experiments
– Wear safety glasses
– Safety is an attitude!
– Don’t take anything out of lab
– Read and follow all instructions
Material Safety Data Sheet
(MSDS)
• Gives information
about a chemical.
• Lists “Dos” and “Don’ts.”
Chemical Exposure
acute exposure
a one-time
exposure
causes damage
chronic exposure
damage occurs
after repeated
exposure
How Toxic is “Toxic?”
Chemicals may cause harm in many different ways.
•
•
•
•
•
•
Flammable
Explosive
Radioactive
Corrosive
Irritant
Toxic
– Chronic toxicity: low doses repeated over a long period of
time
– Acute toxicity: immediate effect of a substance as a result of
a single dose
• “Lethal Dose 50%” LD50
Toxicity
Which is more toxic?
http://lansce.lanl.gov/training/FST2004/images04/chemicals1.gif
Toxicity
Which is more toxic?
Chemical A: LD50 = 3.2 mg/kg
Chemical B: LD50 = 48 mg/kg
Chemical A is more toxic because less of it
proves fatal to half of a given population.
LD50
the lethal dosage for 50%
of animals on which the
chemical is tested
There are various ways an LD50 can be
expressed. For example, acetone has
the following LD50s:
ORL-RAT LD50:
IHL-RAT LD50:
SKN-RBT LD50:
5,800 mg/kg
50,100 mg/m3-h
20 g/kg
Knowledge = Safety
• Material Safety Data Sheet (MSDS)
– Lists hazards, special handling instructions,
and risks associated with a material.
Supplied by manufacturer.
• Acute Exposure
– Single episode can cause great damage
• Chronic Exposure
– Many episodes over a period of time cause
damage
•
•
•
•
Carcinogen – causes cancer
Mutagen – causes mutations (genetic defects)
Tetragen – causes birth defects
Neurotoxin – severely poisonous and toxic