Organic Chemistry 251, 253L, 252, 254L
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This page contains information on how to work safely during a laboratory session.

Click here to access the Nazareth Chemistry Department tutorial. I also suggest you look over the Nazareth College Chemical Hygiene Plan (click here).

SAFETY IN THE CHEMISTRY LABORATORY

There are many potential hazards in the chemistry laboratory and some of them can cause quite a serious accident. However, many accidents in the laboratory can be prevented if each person in the room observes a set of common sense precautions and uses proper experimental techniques and procedures at all times.

REMEMBER YOU ARE RESPONSIBLE FOR THE SAFETY OF EVERYONE ELSE IN THE LABORATORY!

In the following sections, general safety rules and some general techniques are described. Although the list may seem long, an accident could happen if only one of these precautions is ignored. Besides, it is a lot less painful to read this description thoroughly than to suffer the pain of an accident.

GENERAL SAFETY RULES

HANDLING CHEMICALS

KNOW THE LOCATIONS OF SAFETY EQUIPMENT AND LEARN HOW TO USE THEM.
Know the locations of the eyewash fountain, safety shower, fire blanket, and the fire extinguisher nearest to your laboratory bench. Be sure to know who to use this safety equipment. Your action during an emergency might prevent a classmate from serious injury.
WEAR SAFETY GLASSES AT ALL TIMES IN THE LABORATORY.
Goggles are required to be worn at all times! Goggles are available to be worn over prescription glasses. Wearers of contact lenses are discouraged from wearing these lenses during the lab. If no alternative is available, a special release form is required and goggles designed for contact wearers is necessary.
WEAR SENSIBLE CLOTHING.
In the laboratory, sensible clothing includes shoes that fully cover the feet; sandals and clogs are not adequate. Shoes provide a great deal of initial protection in the case of dropped containers, spilled chemicals, and unseen hazards on the floor. Sensible clothing also includes old clothes, which are not too loose, especially at the sleeves. Laboratory coats (available in the bookstore) or aprons are even more satisfactory. All extra clothing, such as coats and scarves, should be kept off the laboratory bench. There are coat hooks provided for this purpose in the laboratory. Tie back of pin up long hair so that it will not fall into flames or chemicals. Do not wear synthetics if possible as they burn readily.
NEVER WORK ALONE IN THE LABORATORY.
All work must be performed under the supervision of a laboratory instructor. The instructor should be aware of the exact nature of all work being done in the laboratory.
DO NOT PERFORM ANY UNAUTHORIZED EXPERIMENTS.
Do only the experiment, which has been assigned by the laboratory instructor. Never do any unauthorized experiment in place of the one assigned by the instructor. Do not change the designated procedure without the advice of the instructor.
KNOW EXACTLY WHAT YOU ARE TO DO.
Occasionally incomplete directions or a misunderstanding of instruction causes accidents. Whenever you are in doubt, ask your instructor. THINK ABOUT WHAT YOU ARE DOING AND WHY YOU ARE DOING IT AT ALL TIMES.
DO NOT start any experiment involving the use of an experimental set-up (apparatus) until it has been checked and approved by your laboratory instructor unless otherwise instructed.
DO NOT EAT, DRINK OR SMOKE IN THE LABORATORY.
For safety purposes, assume all chemicals to be poisonous either by themselves or because of impurities. Also avoid direct contact with organic chemicals. Many are absorbed directly through the skin.
KEEP THE LABORATORY CLEAN AT ALL TIMES.
Any chemical spilled on your skin or your clothing, should be washed immediately and thoroughly. If a solution, a solid, or liquid chemical is spilled on the bench or on the laboratory floor, clean up the spill immediately. Notify the laboratory instructor of the spill. When leaving the laboratory, wipe the bench top thoroughly. Make sure that your work area is clean and free of spilled chemicals or scraps of paper. Wash your hands with soap and water.
DISPOSE OF WASTE AND EXCESS MATERIALS IN THE PROPER MANNER.
Used matches, paper, broken glass, or porcelain ware should be placed in the appropriate containers but not in the sinks or cup sinks. Chemicals should be disposed of in the manner described in the Handling Chemicals section. If you have any questions concerning the waste disposal, ask your instructor for the proper procedure.
USE THE FUME HOOD WHEN NECESSARY.
Use the fume hood when you are so directed by the laboratory instructor, or when it is indicated to do son on the experimental procedure. Fume hoods remove toxic vapors and irritating odors from the laboratory. The removal of these materials is essential for protecting the health and safety of those people working in the laboratory.
LIGHT BURNERS ONLY WHEN NEEDED.
Properly extinguish any flame not being used. Any open flame may ignite reagents being used by you or others near you. Many organic liquids are highly flammable and these liquids should be heated only on hot plates or heating mantles.
NEVER LOOK DIRECTLY into the mouth of an open flask or test tube if it contains a reaction mixture.
AVOID TOUCHING HOT OBJECTS.
When heating a chemical in a container, the clamp holding the container and the burner will also become hot. Place the object on a piece of asbestos board or on wire gauze, which is not directly touching the bench top. Glass objects take a long time to cool, so allow plenty of time to cool before touching them.
USE EXTREME CAUTION WHEN INSERTING GLASS INTO STOPPERS.
Be very careful when inserting glass tubing, glass rods, thermometers, funnels, or thistle tubes into rubber stoppers or corks. Protect your hands by holding the glass and stopper with a cloth towel or multiple layers of paper towels. Always lubricate the glass surface with water or glycerol.
USE ONLY EQUIPMENT, WHICH IS IN GOOD CONDITION.
Defective equipment is an important source of accidents. Some defects to watch for include:
  1. chipped tips on burets, pipets, and funnels.
  2. chipped or broken rims on beakers, flasks, funnels, graduated cylinders and test tubes.
  3. cracks in beakers, flasks, graduated cylinders, test tubes and crucibles.
  4. star-shaped breaks in the bottom of test tubes or near the bottom edges of beakers and flasks.
  5. severe scratches in the bottom of beakers, flasks, and test tubes.
  6. sharp edges on glass tubing and glass rods.
  7. inflexibility in rubber stoppers.
  8. separations in the mercury column of thermometers.
  9. non-working parts of screw clamps, buret clamps or rings.
REPORT ALL ACCIDENTS TO YOUR INSTRUCTOR PROMPTLY!
Report to the laboratory instructor immediately all accidents that cause injury, no matter how minor the injury might seem.
  1. READ THE LABELS CAREFULLY.
GENERAL RULES:
Solutions can exist in a large variety of concentrations; use of the wrong one could lead to unexpected results. Some solids can exist as strips, wires, granules, or powder and sometimes it is extremely important to use the correct one. Also some different chemicals have names that are quite similar. BE absolutely certain that the correct substance and the correct concentration are being used.
  • USE ONLY WHAT IS NEEDED.
    If you take too much of a chemical by mistake, never return chemicals to their original containers because it might containers because it might contaminate the entire supply. If you take too much chemical, follow the direction for the disposal of waste chemicals.
  • LEAVE CHEMICALS IN THEIR PROPER PLACE.
    Bring your own container to the chemical on the reagent shelf rather than taking the chemical to your laboratory bench. This practice reduces the number of trips to he reagent shelf and always keeps the chemicals near their proper place so that others can locate them easily.
  • CLEAN UP ANY SPILL IMMEDIATELY.
    Any chemical spilled on the skin, shelf, table, or floor must be cleaned up immediately. It is especially important to clean up any spilled chemicals on balances in order to avoid corrosion and permanent damage to these delicate and expensive instruments. Be sure to clean up any drops clinging to a reagent bottle after withdrawing the reagent from the bottle. It is the responsibility of the person who spills any chemicals to clean it up because only he/she knows exactly what was spilled and where. The clean up only takes a minute but could prevent an accident.
  • LABEL ALL CHEMICALS.
    When chemicals are obtained from the reagent shelf, be certain that the containers into which they are placed are well labeled. Remember that concentrated sulfuric acid looks just like water. Even if the chemical is to be used immediately, there will probably be some excess, which must be disposed of at a later time. Don’t trust the memory to keep track of all these excess chemicals; use labels.
    Flammable liquids and other liquid chemicals, which cannot be disposed of in the sink, must be placed in marked waste containers for disposal by the laboratory instructor.
    1. OBTAINING THE CHEMICAL.
    HANDLING LIQUIDS.
    Take an appropriate container to the reagent shelf. Avoid measuring volumes of strong acids and alkaline solutions with your graduated cylinder held at eye level. Support your graduated cylinder on your bench; add hazardous liquids a little at a time, inspecting after each addition.
  • REAGENT IN A DROPPER BOTTLE.
    If the general supply bottle is equipped with a dropper, use it, but be sure that the dropper never touches your container or the contents in it. Never put it down on the bench top, but return it immediately the right reagent bottle.
  • REAGENT IN A STOPPER BOTTLE.
    If the general supply bottle is equipped with a stopper, the stopper should either be held during the transfer or placed on its flat top. Do not lay the stopper on its side on the bench top. Pour chemicals from the general supply bottle into your container. Be sure that the proper stopper is returned to the supply bottle; do not interchange stoppers.
  • MIXING.
    If liquid chemicals are to be mixed with water, always add the concentrated chemical to water rather than the other way around. This keeps the new solution dilute at all times and avoids many accidents. Usually addition should be done slowly, using small quantities. It is especially important to add acid to water because of the heat generated.
  • PIPETTING.
    Liquids are drawn into the pipet by applying a slight vacuum at the top, using a small rubber suction bulb but NEVER THE MOUTH.
  • HEATING.
    Liquids in beakers and flasks can be heated by placing them on a ring stand on wire gauze with the container supported by a clamp. Liquid should never be heated in a graduated cylinder or in other columetric glassware.
  • DISPOSAL.
    Check with your laboratory instructor before disposing of any chemicals down the drain. If the liquid chemical can be disposed of in the skin, dispose of it by rinsing it down the sink with large quantities of water. Avoid unnecessary splashing during this process by pouring the chemical directly down the drain while the water is running vigorously.
    1. THE CONTAINER.
    HANDLING SOLIDS.
    Take an appropriate container to the reagent shelf where the general supply is kept. Solids are somewhat more difficult to transfer than are liquids, so a wide-mouthed container such as a beaker is preferable.
  • THE TRANSFER.
    During the transfer, hold the stopper or lay it on the bench without contaminating the stopper. Solid chemicals are most easily poured by tipping the general supply bottle and slowly rotating it back and forth. Mere tipping of the bottle alone often causes large chunks to come out very suddenly which leads to spills. If you use your own spatula, be sure that it is absolutely clean. Return the proper stopper to the general supply bottle; do not interchange stoppers.
  • MIXING.
    If the solid is to be mixed with a liquid, add the solid to the liquid. Additions should be made in small quantities except in special circumstances.
  • DISPOSAL.
    If the laboratory instructor directs you to dispose of any solid chemicals in the skin, flush it down the drain with copious amounts of running water. All other solids should be disposed of in special containers provided for this purpose.

    • IF AN ACCIDENT OCCURS........

    In spite of the best efforts of all concerned, accidents sometimes occur in the laboratory; consequently, we need to have some idea as to what should be done in particular situations. The following are examples of some of the more common accidents. Use good judgment and do not panic in case of an emergency.

    LARGE CHEMICAL SPILLS ON THE LABORATORY BENCH OR AREA.
    In all cases, immediately alert your neighbors and the laboratory instructor of the spill.
    1. If the material is not particularly volatile, nor toxic, and poses no fire hazard:

      2. Liquid can be cleaned up by using an absorbent material which neutralizes them, for example, sodium bicarbonate solution or powder for acids, or sodium thiosulfate solution for bromine. Rubber or plastic gloves should be worn while using absorbent materials. A dustpan and brush should be used to remove the absorbent material. Then, the contaminated area should be cleaned with soap or detergent and water; and the area mopped dry.

    2. If the material is volatile, flammable or toxic:
      ALERT everyone in the laboratory to extinguish flames, disconnect spark-producing equipment, shut down all experiments, and evacuate the laboratory. The laboratory instructor will handle the clean up.
    CHEMICAL SPILLS ON A PERSON.
    1. OVER A LARGE AREA: Within seconds, quickly remove all contaminated clothing while person is under safety shower. Flood the affected body area with cold water for at least fifteen minutes. If pain continues or resumes, flood with more water. Wash off chemicals with a mild detergent solution. Do not apply any materials such as neutralizing agents or salves, to the area. Obtain medial assistance immediately.
    2. OVER A SMALL AREA: Immediately flush area thoroughly with cold water. Wash with a mild detergent solution. If there is no visible burn, scrub the area with warm water and soap.
    3. IN THE EYES: You will need to assist the person who has chemicals spattered in the eyes. Immediately drench the eyes at the nearest emergency eyewash station. Force the eye or eyes open to get water into them. The speed of your response to this emergency is extremely important. Notify the laboratory instructor of the accident immediately.
    SWALLOWING CHEMICALS.
    The laboratory instructor should determine what specific substance ingested.

    The individual should be forced to drink copious amounts of water while en route to medical assistance. The emergency room should be notified while the individual is in transit as to what chemicals are involved.
    BURNS.
    For burns by hot objects, flames or chemical, flush the affected area with cold water for several minutes. Notify the laboratory instructor of the burn and he will arrange transportation to the infirmary if necessary.
    FIRE.
    Security number is Ext. 3333 (Emergency Only) and Ext. 2850 (Non – emergency)
    Give assistance to people first. If the person’s clothes are on fire, guide him/her without running to the fire blanked station or to the safety shower and drench him. Do not hesitate because of such insignificant things as shrinking sweater, ruined hairstyles, or soggy discomfort. While the victims are being cared for other available people should try to shut off or reduce the fuel supply to the fire. Get a fire extinguisher and direct its spray toward the base of the fire. If the fire is too big to extinguish, have the laboratory instructor call the fire department and sound the fire alarm.When the fire is out, be sure all extinguishers used are tagged as empty and are replaced.
    INJURY OR ILLNESS.
    Render assistance if necessary. For minor cuts, wash them thoroughly, apply a good antiseptic, and a band-aid. For major cuts, severe bleeding or serious illness, send someone for help and administer first aid. Only a physician is trained to treat serious injury or illness. Notify the instructor immediately.
     

    Fall Organic Exps Lab Expectations Lab Safety

    Timm A. Knoerzer
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    Naz Chem. Dept.
    Naz. Home Page

    Last Updated Saturday, August 28, 2004 06:49:00 PM