Physical Chemistry Lab
Overview of Safety Guidelines, Procedures, and Practices
1. PPE
Personal Protective Equipment: What must
be worn when you work in the laboratory.
Eye Protection
Lab Coat
Long Pants
Closed Toed Shoes – no exposed skin around feet
Lab gloves – when required
2
Eye Protection
• Contact lenses are OK as long as glasses/goggles are worn
• Prescription glasses – you must wear goggles over them
• Safety goggles are provided in organic labs in UV irradiating
cabinets
• Eye wash stations are present in all labs
3
Clothing and Foot Protection
• Clothing must cover all
exposed skin including
legs/ankles
• Stockings or leggings do not
provide good coverage
• Sandals, flip-flops, Crocs,
open-toe and open-top (i.e.
ballet flat) shoes and canvas
shoes (i.e. Toms) are not
appropriate. These are not
going to protect your feet if
you drop a piece of glass with
a liquid chemical reagent in
it.



4
Use of Gloves
Remove gloves before handling objects such as
doorknobs, telephones, pens, computer keyboards,
pH meter or other electronic buttons, or phones
while in lab. It might be convenient to have one
gloved hand and one ungloved hand to do
procedures where these kinds of things are used.
• Throw away gloves anytime you take them off.
• You should expect to use several pairs of gloves in
any given lab period.
• Glove video
5
Eyewash / Safety Shower
The eyewash
is on the left.
Pull the
handle and a
fountain of
water will
appear that
you can use
to bathe your
eyes.
The safety shower is
on the right. Pull the
handle and water will
start spraying from the
shower head on the
ceiling. There’s no
drain in the floor – we
only do this in
emergencies, because
a flood of water will
have to be cleaned up.
6
Eye Wash
7
Safety Shower
8
Using the Fume Hoods properly
This
window/bar
is called
the sash.
If this is not saying NORMAL, then the hood
is not protecting you. Keeping the sash
and sliding panels in proper position keeps this
NORMAL, otherwise the alarm goes off.
If the alarm goes off, you need to reposition
things to the correct positions, then press the
“mute” button to reset the controller.
The sash should never be raised above
the green “operation” level when you
9
are working in the hood.
In use, side-to-side panel
used as shield
Closed, not in use
✓
In use, sash (window) raised
to less than 18 inches
✓
✓
Don’t open side shields
to make one big window.
×
10
• When using a laboratory hood, Check that the airflow is
in the normal range on the digital display
• Turn on the hood light
• Set the equipment and chemicals back at least 6 inches.
• Never lean in and/or put your head in the hood when
you are working. This is worse than doing the
experiment with no hood at all.
• It’s a good idea to put liquid reagent containers in trays
to catch all spills and drips
11
Fire Alarms –
know the location of one close to your lab
12
Fire Extinguishers – we have several in
the labs and in the hallways.
13
14
Types of Fire Extinguishers
This is a special
fire extinguisher
for combustible
metal fires. It is a
type D fire
extinguisher. You
won’t need to
use this unless
you work in a
research lab with
combustible
metals.
Most of our fire extinguishers are ABC.
It contains a dry powder to put out the
kinds of fires we might encounter in the
chemistry labs where we have class.
15
Student Reaction in a Fire
Although we want you to be informed on the operation of a
fire extinguisher, we do not expect you to use it. If a fire is
ignited in your area, the proper STUDENT response is to:
1) Notify everyone in the room
2) If possible shutdown any reaction in progress by removing
heat/energy source
3) Proceed to the nearest exit and pull the nearest fire alarm
4) Evacuate the building
5) Assemble in front of the library or in the YWCA parking lot
for a positive headcount
16
Keep your lab area clean.
×
Throw away used
paper towels and
used gloves,
immediately.
×
Don’t block the floor
in front of the
eyewash/shower
station.
×
Don’t leave cords
dangling because
someone will trip
over them.
×
Don’t leave things in
the floor because
someone will trip
over it.
17
Once again, the number to call in an emergency is:
843-953-5611
Please take a moment now to program
this number into your cell phone.
18
Cryogens
• Cryogens: liquefied gases that are kept in their
liquid state at very low temperatures.
• Used to access low temperatures
• Boiling points below -150°C (- 238°F)
• High expansion ratios (average 700:1)
• When they are heated (room temperature)
they vaporize very rapidly
– If volume cannot be expanded, the pressure will
increase and possibly blow something up
Handling Cryogens
• Know the properties of the cryogens before
handling them
• Examine equipment before use
• Many materials shrink, become brittle, or
crack at such low temperatures, so take care
when selecting materials to be used with
cryogens.
• Spilled cryogens can expand to gas rapidly and
displace air in enclosed areas
Handling Cryogens
• If using cryogens to cool an object,
insert the object slowly using tongs
– this minimizes boiling and splashing
• Jewelry can freeze to exposed skin
• Exposure can cause severe frostbite
• Always wear proper PPE that covers
Legs, feet, and arms, safety glasses or
Face shield and thermal gloves
Physical Properties of Common
Cryogenic Liquids
Cryogen
Boiling
point (1
atm) °C
(°F)
Critical
pressure
psiga
Liquid
density,
g/L
Gas
density
(27°C), g/L
Liquid-togas
expansion
ratio
Type of
gas
Ar
-186(-303)
710
1402
1.63
860
Inert
He
-269(-452)
34
125
0.16
780
Inert
H2
-253(-423)
188
71
0.082
865
Flammable
N2
-196(-321)
492
808
2.25
710
Inert
O2
-183(-297)
736
1410
1.4
875
Oxygenb
CH4
-161 (-256) 673
425
0.72
650
Flammable
Using Dewars
• A Dewar is the typical container used to store and handle
cryogenic liquids
• A multi-walled design with a vacuum jacket for insulation and
pressure relief valves to protect against over-pressurization
• Containers filled with cryogens should never be capped tightly
Liquid Nitrogen Safety
• LN2 rapidly evaporates and can displace air
in enclosed spaces causing suffocation
• LN2 can cause death of human tissue from
extreme cold
• Minor contact can cause “burns”
• Evacuated glass dewars can sometimes burst
unexpectedly
• LN2 can condense liquid oxygen, a highly
reactive and flammable liquid
Liquid Nitrogen DON’T’s
•
•
•
•
•
•
DON’T use in confined space
DON’T freeze items in centrifuge tubes with snap caps
DON’T transport LN2 in a closed automobile
DON’T transport LN2 in a passenger elevator
DON’T allow a storage dewar to tip over
DON’T leave cold fingers on a vacuum line in LN2
overnight
• DON’T use without PPE!
NO!
Liquid Nitrogen Do’s
YES!
• DO use or dispense LN2 only in well ventilated areas
• DO ensure glass dewars are taped or wrapped
• DO use approved containers only such as a dewar or
NO!
threaded cryovials for storage
• DO make sure any vessel with LN2 is VENTED
• DO secure storage dewars against spilling
• DO use appropriate PPE which includes:
• Face shield (or minimally goggles)
• Long thermal gloves
• Apron or lab coat
YES!
• Closed toed Shoes
• Long pants
Special Note on LN2 transport for Chemistry Magic Shows
•
•
•
•
Use only a sturdy LN2 dewar
Keep windows of car open
Do not put LN2 next to any passenger in the car
Secure the LN2 such that it cannot tip over (use seatbelt, other
heavy, bulky objects to block it in)
• Be prepared to leave the vehicle if a spill occurs
• Do NOT allow K-12 students to touch LN2
• Do NOT allow K-12 students to approach your glass dewar without
goggles
Nanomaterials (CdSe QDs)
• Particles that are 100 nanometers or less in size and behave as a whole
unit in terms of its transport and properties.
• The reactivity of many conventional materials change when in
nanoparticle form
• The toxicology of many nanomaterials have not been determined
• Full PPE should always be worn when working with nanoparticles and
lab coats and other contaminated clothing may need to be
professionally laundered
• Absorption and inhalation are common exposure routes
• Nanomaterials can accumulate in areas of the body remote from the
area of exposure
• Nanomaterials
Gas Cylinders
• http://www.youtube.com/watch?v=mReuQCuJNQQ
• A gas cylinder will become a missile if the valve is
broken or cracked.
• For this reason, gas cylinders must always be securely
chained to a wall or a permanent bench in the lab. The
chain should not be loose.
• If a cylinder is not in use or is going to be moved, it
must be capped to protect you and everyone else in
the building.
• Do not attempt to move a gas cylinder until you have
been trained on this important procedure.
29
Gas Cylinder Safety
×
✓
Do not attempt to adjust
valves on regulators
regulator
30
Gas Regulators
• Flammable gases and inert gases have
different types of regulators---do not mix!
• One gauge measures the internal tank
pressure and the other gauge can be
adjusted to regulate the output pressure
• Know the pressure limits of the
equipment that you are attaching to the
regulator on the output side
• Never open a tank without a regulator
• Only make small incremental adjustments
to output pressure
Valve to adjust output pressure
Gas Tank Labels
• It is important to
know when a tank
is empty or
pressurized
• Standard labels are
attached to tanks
on delivery and
should be modified
by user as the tank
is being used and
then emptied
Manipulating Gas Cylinders
• Gas Cylinder Use