Lab Safety:   Ms. Bebora-Abergos

General safety in the lab: Accidents in the chem lab, as in the home or work place, can be prevented: Stop to think!. Common sense will help, if exercised What will be the consequences of what I do next? If in doubt, ask the teacher.

The following scenes 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! 

Handling of Acids or Bases Many schools will require the use of personal protective equipment, such as gloves. However, cream-colored latex gloves (see photo) are no longer recommended (due to allergic responses). "Vinyl" gloves or "nitrile" gloves (often green or blue in color) are preferred.  

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.

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 dry-chemical extinguisher on a fellow human being. The powder may get in the victim’s eye and cause irritation.

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.

USAGE: 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.

USAGE: Squeeze the handle to begin operation.

Fire Blanket  Rarely used on humans, now, but your school may still have them. Good for fires involving equipment A dry-chemical extinquisher would trash a computer

Usage: - Wrap it around the victim to smother the fire. -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! Don't wait until lunch or thelast period! Run some water through the eyewash fountain before you use it. Retract your eyelid (hold it open);

Eyewash Fountain Don’t squint your eyes this restricts water access. Run fresh water over your eye for several minutes. If the water at your school is COLD Wash your eyes INTERMITTENTLY Rest in between rinses. Go to the school nurse immediately afterward.

First Aid Kit   These items may be used temporarily for small injuries (say, a cut finger) Go to the school nurse immediately afterward. Do not wait until the end of the day. However, if blood is in evidence-- STAY AWAY! Let the victim apply his/her own bandage. If blood is on the floor or lab bench, let trained personnel do the clean-up.

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. But: there is probably no floor drain.

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, a milk carton is an acceptable substitute.

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.

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.

Use of pipettes When using pipets, DO NOT suck the liquid into the pipet directly by mouth. Frequent mistakes, even by skilled lab workers, lead to the liquid reaching the mouth.

Use of pipettes DO use a rubber bulb to create a vacuum.

TESTING of ODORS: Do NOT smell the flask directly.

TESTING of ODORS: 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.

Handling of hot objects: Remember NOT to hand the red-hot glass rod to another person, especially the teacher.

Heating of test tubes: Make sure that reaction tubes, e.g. test tubes, are not directed toward yourself or other persons. The chemicals may splatter out the tube.

Heating of test tubes: A better technique:

Adding Acids to water: DO NOT add WATER to CONCENTRATED ACID. The heat generated may cause splattering. Your school probably will not allow you to use concentrated acids anyway, so keep this info in mind for future reference.

Adding Acids to water: If necessary to prepare certain solutions, 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. Always wear eye protection.

Things to do Before lab: A GOOD PRACTICE:  Read the experimental procedure ahead of lab. NOT as y-o-u d-o t-h-e p-r-o-c-e-d-u-r-e Mistakes, then, are common. To be sure, this may be difficult in high school, but in college, it absolutely will be required.

Bunsen Burner Usage Make sure the rubber hoses are firmly attached. Both at the gas outlet and at the burner. Otherwise, the flame may "strike-back". If a "flame-out" nevertheless occurs, merely turn off the gas.

Bunsen Burner Usage To light a Bunsen burner: Turn up the gas flow until you hear a gentle flow of gas. Light the burner by bringing the match UP from the base toward the burner nozzle. Remember:  down-to-up!

Bunsen Burner Usage Disposal The match should be quenched with water at the faucet, NOT thrown into the waste directly.     You may think the match flame is out, but  Fires may still occur from the smoldering match.

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. If the glassware present becomes broken, the situation is dangerous!

The Best Idea of All Have a Safe Year!