SAFETY AND TECHNIQUES  IN THE CHEMISTRY LABORATORY

Written by a SLCC student, Kirk Hofeling as an assignment for  his Technical Writing class.

Refer to   Chemistry Laboratory Safety and Techniques slide show.  http://www.slcc.edu/redwood/chemistry/labs/labshows/PPTshows/labs/sld001.htm)
To return to this document from the slide show, you need to use the BACK button in the upper left-hand corner of the screen.

Everyone in the laboratory is responsible for their own safety and the safety of  other people in the lab. In the chemistry laboratory there are many sources of potential hazards.  These dangers include: broken glass, foreign bodies in the eye, and falls.  The corrosive, flammable, and toxic chemicals, in the laboratory pose unique dangers. Laboratory equipment if used improperly can cause burns, electrical shock and explosions. By being aware of the basic laboratory safety rules and techniques you can prevent the majority of accidents in the laboratory.

General safety rules
1. Be prepared for the lab.
Read the experiment, including the procedure, complete the pre-lab assignment, and be familiar with the chapter in the text that covers what will be done in the lab before attempting the experiment.

2. Wear only  approved eye protection. Do not wear contact lenses.
Ordinary eye glasses (prescription or sunglasses) do not offer adequate protection. Everyone in the laboratory must wear eye protection that meets Occupational Safety and Health Administration (OSHA) standards  Eye wear must be shatter-resistant, and  protect the front and sides of your eyes.
Contact lenses are dangerous because they can trap chemical vapors and foreign matter under the lenses. They also interfere with the proper function of eyewash fountains. If you must wear contact lenses for medical reasons, fitted goggles must be worn at all times in the lab.  The laboratory instructor must be informed  in the first lab session if you must wear contact lenses.

3. Wear only appropriate  laboratory clothing.
Never wear shorts, sandals or open-toed shoes, tank-tops, etc. on a day you will work in the laboratory. Short skirts are  also unacceptable.
A common area for chemical burns are the legs and feet.  Do not wear unbuttoned, loose-fitting clothes. Lab coats are encouraged but not mandatory. However, in you do not wear a lab coat,  wear the clothes that you do not value too much, as they may be damaged in the lab.

4. Confine long hair  in the laboratory.

5.  Know the location  and use of the emergency equipment in the laboratory.
During your first meeting the lab the instructor will point but the location and operation of the eyewash fountain, safety shower, fire extinguisher, fire blanket and the fire exits.  You need to know the location and  proper use  of the safety equipment.  It could prevent serious injury to yourself or a class mate.

6. Do not smoke, apply cosmetics, chew tobacco, consume food or drink, or chew gum in the laboratory.

7. Use common sense when working in the  laboratory.

8. Wash your hands before leaving the laboratory.

9. Practical jokes or horseplay are not allowed at any time.

10. Do not perform unauthorized experiments or attempt experiments without the lab instructor's supervision.

11. Do not use chipped, cracked or broken glassware.  Damaged glassware should be placed in the broken glass container.  Broken glassware should  NEVER be placed in a trash can.

12.  Maintain the equipment and work areas  in clean conditions.

LABORATORY CLEANLINESS
There is a relationship between safety, performance, and orderliness in the laboratory.  When cleanliness standards fall, safety and performance deteriorates. Work areas and equipment in the laboratory should be kept clean.
To maintain proper standards:
 - clean the equipment after every lab,
 - use only clean equipment.  If you use dirty equipment it could cause unexpected results in your experiment,
 - return reagents, waste, and equipment to the proper place after use (the lab cart or a fume hood),
 - never block the aisles between lab benches or clutter the bench with unnecessary item such as backpacks, coats, and   books (these items should be placed in the cubicles on the back wall of the laboratory),
The only items that should be on the lab bench are laboratory instructions, a pen,  a lab notebook, and the items necessary to complete the lab.

ACCIDENTS IN THE LABORATORY
Preventing of  accidents in the laboratory
The following actions  will help decrease the likelihood of an accident:
 - keep the work area clean (clutter increases the likelihood of a spill or accident),
 - always replace the cap on chemical containers after use,
 - never take any containers with chemical reagents from the lab cart or the fume hood  back to the work area. Transfer  only the  required amount of a chemical needed to perform the experiment into a separate container,
 - dispose of broken glassware in the broken glass box,
 - do not engage in roughhousing or horseplay in the laboratory,
 - use common sense when working with hot objects.
To avoid ingesting chemicals:
 - do not bring FOOD AND DRINK to the laboratory,
 - do not CHEW GUM,
 - do not chew your fingernails,
 - do not lick your fingers to turn a page,
 - wash your hands before leaving the laboratory,
 - use fume hoods when instructed to do so,
 - do not apply lipstick or chap stick when in the lab.

What to do when an accident happens?
Be alert to unsafe conditions and actions and call attention to them, so that corrections can be made as soon as possible.  The first thing that should be done in the event of any accident is to inform the laboratory instructor. Remain out of the area of an accident unless directed by the lab instructor to help.

Chemical spills in the laboratory
If a chemical spill occurs, follow this procedure:
1. Immediately notify the laboratory instructor and  students in the area of the spill.
      If using flammable  chemicals, ask everyone in the laboratory to extinguish all flame producing devices.
2.  Inform the laboratory instructor of the type and   amount of chemical spilled.
3.  Follow the laboratory instructor's instructions.

Chemicals spilled on your body
A. Over a large area.
     Inform the laboratory instructor while you :
    1.  Quickly move to the safety shower, stand under the shower and activate it.
    2.  Quickly remove any contaminated clothing while flooding the contaminated area.
    3.  Flood the contaminated body area for at least 15 minutes.
B. Over a small area.
    Use the sink instead of the safety shower.  The affected area should be drenched in the sink for at least 15 min.
    Always inform the lab instructor.

Chemicals in the eyes
If a chemical splashes into your unprotected eyes:
1.  Immediately call out for assistance in getting to the eye wash fountain.
2.  Drench your eyes at the eyewash fountain for at least 20 minutes.  While flushing your eyes force
     your eyes wide open, and rotate your eye balls to ensure that all areas are flushed.
4.  Inform the laboratory instructor of the amount and type of chemical that you got in your eyes,
     so the instructor can take the appropriate action.

If chemicals are spilled on your face and your eye protection prevents the chemicals from getting into your eyes:
DO NOT REMOVE YOUR EYE PROTECTION.   Move to the eyewash fountain and drench your face and eye protection for at least 15 minutes.  Then remove the goggles and start at step 2  above.

Ingestion of chemicals
If you believe that you have ingested a chemical,  inform the laboratory instructor of the type and amount of the chemical, so the instructor can take the necessary action.

Burns
In case of thermal burns follow these instructions:
1.  Notify the laboratory instructor.
2.  Flush the effected area with cold water for at least 15 minutes.
3.  The laboratory instructor will determine whether medical attention is needed.

Cuts
With the large amounts of glassware used in the laboratory,  cuts  may occur.
If you are cut in the laboratory inform the laboratory instructor who will provide the  first aid.

Fire
If your clothing catches on fire, DO NOT RUN to the safety shower or fire blanket, call for help while doing the following:
1.  STOP where you are.
2.  DROP to the floor.
3.  ROLL to smother the flames.
4.  Someone else will get an emergency fire blanket to help extinguish the flames.
5.  Once the fire is out, immediately go the nearest safety shower and drench the burned area with
     water.

HOW TO SAFELY HANDLE THE EQUIPMENT ?
Use only the  equipment that is clean and in good condition. If your glassware or other equipment is dirty, clean it. I chipped- have it replaced.
Use common sense when working with heating devices and hot objects. In the laboratory burns are one of the most common injuries. To avoid burns follow these guidelines when working with heat producing reactions, hot plates, or Bunsen burners:
1. When  heating solid or solution, or performing a heat producing  reaction in a test tube, use a metal test tube holder.
  NEVER use a plastic-coated clamp as a test tube holder !
2.  When observing a heat producing reaction in  a flat bottom glassware, such as a beaker, place it on a ceramic fiber pad on the lab bench.
3. When heating a piece of glassware you also heat the clamps or other devices supporting the glassware.
    Be aware of this fact  when adjusting, moving glassware, or heating apparatus.
4.  Never leave any  heat source unattended.
5.  Ignite open flame (Bunsen burner)  only when no flammable solvents are in the vicinity.

HOW TO SAFELY HANDLE THE CHEMICALS?
The general rules for safely handling the chemicals are as follows:
 - treat every chemical as though it were hazardous,
 - never touch any chemicals with your bare hands,
 - use the proper personal protective equipment,
 - after handling chemicals, wash your hands,
 - use correct laboratory techniques,
 - always use common sense.

Safety labels
Always read the label on the reagent you intend to use to ensure that you select the correct reagent with the proper  concentration for your experiment.

Be aware of the hazards associated with the chemicals you will be using.
Every reagent container you use will have a NFPA label divided into four colored parts:
BLUE color indicates HEALTH hazard associated  with a reagent,
RED color indicates FLAMMABILITY,
YELLOW color indicates REACTIVITY
WHITE color indicates UNIQUE PROPERTIES of the reagent, such as corrosive, radioactive, biohazard, etc, .

Material safety data sheets  (MSDS)
Material safety data sheets are another resource helpful  in determining the hazards associated with a chemical. An MSDS will contain the NFPA hazard ratings, physical data, (melting point, boiling point, flash point etc.), first aid, storage, disposal, protective equipment, and spill/leak procedures.  The MSDS for a specific reagent can be obtained in the laboratory or online by doing a Google search (http://www.google.com) of the compound name in quotation marks and the term MSDS. For example, in looking for an MSDS for sulfuric acid, go to Google and type

"sulfuric acid" MSDS

in the search box. You can also use other search engines such as HotBot, AltaVista, Kartoo, Yahoo, and others to search for information. If one search engine does not provide you with useful information, try another.

Fume hood
When working with chemicals or chemical reactions that produce toxic, or strong irritating fumes use the fume hood. Before  using a fume hood, make sure that it is turned on.  When using  the fume hood do not lean into or place any portion of your body in the hood except you hands and lower arms. Make sure that your face is protected by the glass shield. Never kneel in front of the hood.

Disposal of chemicals
1.  Follow the directions of the laboratory instructor when disposing of residual waste or unused reagents.
2.  Make sure that the container you  are planning waste in has a label that correctly describes the waste you
     are disposing.
3.  Do not fill waste containers past 80% full to avoid  spilling.

Detecting odors
Use the proper method if you wish to identify a chemical by its smell.  If you need to detect an odor for an experiment waft the vapors toward your nose with a cupped hand.  Never place your face directly over a beaker or other container and inhale or attempt to taste a chemical.

TRANSFERRING LIQUIDS
The correct method for obtaining a liquid depends  on the amount of liquid to be used, and the container the liquid comes in.

Transferring a large amount (more that several milliliters) of  liquids from a stoppered bottle
A. Pouring into a large-mouth container:
1.   Remove the stopper from the bottle.
2.   Hold the stopper between your middle and index fingers.  If you must  lay the stopper down, place it on a clean piece of
      paper. This will help to avoid contaminating the  stopper or  getting it mixed up with another stopper.
3.   Carefully pour the liquid from the reagent  bottle to your container, using twisting motion towards the end
     (or touch the mouth of the bottle to the side inside edge of a beaker to remove the last drop).
4.   Replace the stopper.
B. Pouring into a narrow-mouth container :
Use a funnel to transfer the liquid from a bottle into a narrow-mouth container.

Transferring a small amount of  liquids from a stoppered bottle or a beaker
Follow the steps outlined in the slide show : Transferring a  small amount of liquid.

Transferring a liquid from a dropper bottle
1.  Unscrew the dropper from the bottle, do not try to pull the dropper out of the cap.
2.  Squeeze the rubber bulb at the top of the bottle.  Release pressure on the bulb allowing the liquid to
     flow into the dropper. Do not allow the solution to  reach the bulb.
3.  Transfer the liquid to your container. Keep the dropper in a vertical position, bulb up.
     Avoid touching your container or its contents with the dropper to prevent  the contents of the dropper bottle  from  contamination. Do not at any time lay the dropper down  but  place it back in the bottle, to avoid contaminating the bottle contents.