Physical Chemistry Lab Overview of Safety Guidelines, Procedures, and Practices

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Personal Protective Equipment: What must be worn when you work in the laboratory.

1. PPE

Eye Protection

Lab Coat

Long Pants

Closed Toed Shoes – no exposed skin around feet

Lab gloves – when required

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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

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• 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.

Clothing and Foot Protection

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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

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Eyewash / Safety ShowerThe 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.

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Eye Wash

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Safety Shower

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Using the Fume Hoods properly

If this is not saying NORMAL, then the hood is not protecting you. Keeping the sashand sliding panels in proper position keeps thisNORMAL, 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 abovethe green “operation” level when youare working in the hood.

This window/bar is called the sash.

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×✓

✓✓

Closed, not in use In use, side-to-side panel used as shield

In use, sash (window) raised to less than 18 inches

Don’t open side shields to make one big window.

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• 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

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Fire Alarms – know the location of one close to your lab

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Fire Extinguishers – we have several in the labs and in the hallways.

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Types of Fire Extinguishers

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.

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.

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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 room2) If possible shutdown any reaction in progress by removing

heat/energy source3) Proceed to the nearest exit and pull the nearest fire alarm4) Evacuate the building5) Assemble in front of the library or in the YWCA parking lot

for a positive headcount

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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 things in the floor because someone will trip over it.

Don’t leave cords dangling because someone will trip over them.

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843-953-5611Please take a moment now to program this number into your cell phone.

Once again, the number to call in an emergency is:

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 coversLegs, feet, and arms, safety glasses orFace shield and thermal gloves

CryogenBoiling point (1 atm) °C (°F)

Critical pressurepsiga

Liquid density, g/L

Gas density (27°C), g/L

Liquid-to-gas 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

Physical Properties of Common Cryogenic Liquids

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• 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

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• Closed toed Shoes• Long pants

YES!

NO!

YES!

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

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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.

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Gas Cylinder Safety

✓regulator

Do not attempt to adjustvalves on regulators×

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