Lab Safety:  Accidents in the chem lab, as in the home or work place, can be prevented:   1. Stop to think!. 2. Common sense will help, if exercised 3. What will be the consequences of what I do next? 4. If in doubt, ask the teacher.   The following scenes graphically illustrate some difficulties as well as downright dangers that you could face in lab, mostly due to failure to observe ordinary safety precautions, and

common sense.

  Personal Protective Equipment  Many states require by law that students wear approved safety goggles or safety glasses when in the lab. This is an absolute "MUST"!  

         

 

The following is not acceptable! 

     

Proper attire:• Avoid floppy garments; avoid things that dangle • These get tangled up in equipment or glassware and

cause accidents • Avoid long, loose hair styles for the same reason. • When Bunsen burners are in use, long hair sometimes

catches on fire • The Safety Code of most schools will not approve of open

footware; so avoid sandals, thongs

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Safety Equipment

• Fire Extinguishers

• Fire Blanket

• Eye-wash Fountain

• First-Aid Kit

 

Fire Extinguisher Operation • There are two main types of fire extinguishers,

•   carbon dioxide • dry chemical (powder) •   Often, but not always, they carry different colors.

• In this case the carbon dioxide extinguisher is red, and the dry-chemical (powder) extinguisher is yellow.

• Read the tag to know which you will use. The tag also should show the date the extinguisher was last serviced.

•  

Fire Extinguisher Operation• Carbon dioxide extinguishers are good,

general purpose extinguishers.

•   Dry-chemical (powder) are used for difficult cases, say certain types of electrical fires. AVOID using a ANY extinguisher on a fellow human being.

• Why? 

Fire Extinguisher Operation• USAGE:

•   Locate the "KEY" (the round object)

• Twist the "KEY" to break the stiff Nylon retaining cord then pull "KEY" out

• Do not merely attempt to pull the key straight out, unless you are very strong.

•

•  •   •   •   •   •  

Fire Extinguisher Operation• Raise the nozzle in order to direct the stream of

carbon dioxide • The CO2 will cool the fire, and restrict oxygen • The fire, lacking oxygen, should go out.

Fire Extinguisher Operation• Squeeze the handle to begin operation.

Fire Blanket • Yank the blanket out of the wall holder.

• Wrap it around the victim to smother the fire.

Eyewash Fountain • If you get something from the lab in your eye— • GET IT OUT IMMEDIATELY! • Run some water through the eyewash fountain

before you use it. • Retract your eyelid (hold it open); • Don’t squint—this restricts water access. • Run fresh water over your eye for several

minutes. (20 minutes for acids or bases)• Go to the school nurse immediately afterward.

Eyewash Fountain

First Aid Kit • Since we have a full time nurse, only

band-aids are kept in the classroom

• For more serious injuries the nurse or 911 will be called.

Use of the FUME HOOD – Not every school will have a fume hood available. – If your school has a FUME HOOD—use the HOOD for

reactions that give off vapors, especially smelly vapors.

– The draft of the HOOD will sweep away vapors so that the

lab itself maintains reasonable air quality.

•  

Safety Shower • Again, not every school will have one. • Shower should be used for dire EMERGENCY only! • If you (or a lab mate) is ON FIRE, position yourself (or your lab

mate) under the safety shower. • Pull the handle—a deluge of water will result. • Flames will be rapidly extinguished

Safety Shower– The safety shower should also be used if you

suffer a massive spill of a dangerous chemical on yourself, and need to get it off rapidly.

•  However, in a high school laboratory, this will seldom be necessary.

•  

Broken Glass

• Sweep it up right away

• Don’t track in it all period.

Broken Glass– Place the broken glass in a "SHARP’S CONTAINER.

• This is a thick walled carton, that will be sealed and discarded as such.

– If such a container is not available, the trash can is an acceptable

substitute.

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Materials Safety Data Sheets(MSDS)

– When a chemical is purchased, the supplier will send a MSDS sheet.

– The MSDS sheet lists the known dangers of the chemical in question.

– Your school should keep a file of MSDS sheets.

– We have MSDS sheets attached to most chemicals

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Safety Warning "Diamond" – Know the significance of these symbols.

• You will see these frequently in adult life. • RED is FIRE DANGER

– rated on a 0-4 basis. » If, for example, ether is present, a very high rating of 4

would be indicated. • Yellow indicates REACTIVITY danger.

– often "WATER REACTIVE" dangers » Sodium metal, if present, would require a 4 rating. » Sodium represents a danger to firemen, who might

come busting into this area with a high pressure hose. • BLUE represents HEALTH HAZARDS, • WHITE signifies specific hazards, e.g. oxidizers, acids,

bases, or corrosive materials.

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Student Use of the Laboratory

No UNAUTHORIZED experiments!

These are terrible dangers in unskilled hands

Student Use of the Laboratory– No EATING or DRINKING in the LAB.

• A good practice is to assume everything in the lab is toxic.

•  

Student Use of the Laboratory• DO NOT drink from lab equipment.

• NOT EVEN distilled water.

Student Use of the Laboratory• You do not know what another person

might have added to the "distilled water" jug.

Student Use of the Laboratory– TESTING of ODORS:

• Do NOT smell the flask directly.  

– If you absolutely must test the odor, carefully waft the vapor from the flask toward your nose with your hand.

• Keep the flask quite distant from your face.

Student Use of the Laboratory• Proper heating of glass tubing or glass

rods in order to bend it:

Student Use of the Laboratory• Remember NOT to hand the red-hot glass

rod to another person, especially the teacher

Student Use of the Laboratory• Make sure that reaction tubes, e.g. test

tubes, are not directed toward yourself or other persons.

• The chemicals may splatter out the tube

Student Use of the Laboratory– A better technique: –  

Student Use of the Laboratory• DO NOT add WATER to

CONCENTRATED ACID.

• The heat generated may cause splattering.

Student Use of the Laboratory– DO add ACID to WATER instead of the reverse order of addition.

• The heat generated will be less, but splattering still may occur.

• A good practice in all lab operations is to keep things at arm’s

length.

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Student Use of the Laboratory• A GOOD PRACTICE:

• Read the experimental procedure ahead of lab.

• NOT as you do the procedure

– Mistakes, then, are common.

Bunsen Burner Usage

• Make sure the rubber hoses are firmly attached.

• Both at the gas outlet and at the burner.

Bunsen Burner Usage• Strike the match BEFORE you turn on the gas.

• Turn up the gas flow until you hear a gentle flow of gas. The burner should quickly light.

• Run water over the match, then place it in the green pan, NOT the sink.

Avoid Horseplay • In a laboratory setting, horseplay, even if good-natured, is absolutely

unacceptable.

• No pushing; no shoving.

• Serious accidents all too often result involving the glassware or solutions in use.

At the end of the lab period:• Exit the lab in an orderly manner.

• Again: no running, no pushing, no shoving.

Have a Safe Semester!