Basics of lab safety

Objectives. After completing this module you should be able to

  • Identify potential biohazards, chemical hazards and unsafe situations
  • Know where to get safety and emergency information about chemicals in the lab
  • Protect yourself and students from chemicals and potential biohazards
  • Maintain a safe lab environment

A Safe Lab not only keeps you and your students safe, but also takes into consideration others who might be affected, such as the janitor, other people who use the room and the rest of the building.

Safety Clothing (Personal Protective Equipment)

  • Lab Coat:keeps clothing clean and prevents chemicals from getting on clothing and skin
    • If clothes get hazardous chemicals on them, they must be thrown away.
    • If they are put in the washer and dryer they will contaminate everything else in the wash and contaminate the next load of wash. Flammable chemicals may ignite in the dryer.
  • Disposable gloves:
    • Prevent chemicals from getting on skin
    • Prevent contaminants on hands from getting into reactions
  • Safety goggles
    • prevent splashes to the eyes
  • Shoes
    • Wear rubber-soled shoes to prevent slipping on liquids
    • Choose shoes that cover your feet and will protect them from drips
      • No sandals or mesh shoes

Chemical Safety

  • Many chemicals are unsafe if used improperly
  • Avoid getting chemicals on your skin and never sniff a bottle
  • Material Safety Data Sheets:This safety-related documentation is available online
    • An MSDS contains information on how to handle chemicals, specific dangers, and how to contain a spill
    • Collect MSDSs for each chemical in the lab and keep them in a folder in the lab
  • Spills:
    • Many chemicals can be contained by absorbing them and carefully disposing of them
    • Be especially careful with flammable substances
    • Avoid using cleaning products as this may create harmful chemical reactions
    • Refer to the MSDS for specific clean up info
  • NFPA Hazard Labels
    • Chemicals will be labeled with a “fire diamond” indicating the degree of hazard
    • The second figure shows how to interpret a hazard label
  • Ethanol-NFPA-Chemical-Label-LB-1591-052.gif
external image nfpa-big.gif

Good Chemical Safety Practices

  • When wearing gloves, don’t touch things that other people touch with their bare hands
    • This includes doorknobs, freezer handles, faucets, etc.
    • Turn gloves inside out as you remove them to keep hazardous chemicals on the inside
    • Change gloves if they tear
  • Labeling
    • For the safety of others who may not be familiar with the lab, LABEL EVERYTHING
    • Don’t leave unlabeled bottles or beakers out, even if they contain something harmless like water. Many clear, colorless liquids look alike.
    • Label each container with
      • Chemical or mixture name (e.g. “TAE Buffer”)
      • Date
      • Your name or initials, so people know who to ask if they have a question
  • Storage
    • Store chemicals in their original containers. These containers were specifically designed for the long-term safe storage of these chemicals
    • Store prepared chemicals (i.e. diluted buffer) in bottles with screw-on caps
    • Be sure to label bottles with the contents, date, and your name

Biological Safety

  • Biohazards include potential infectious materials and other hazards
  • Common biohazards include
    • Blood: may contain parasites, bacteria, or viruses
    • Molds and fungi: commonly found in soils and organic materials
  • Common Routes of Entry. You can potentially become infected if you
    • TOUCH something without gloves and have cuts or scratches on your hands (even tiny ones)
    • INHALE hazardous substances such as mold or fungal spores, dried material containing virus or parasites
    • get infectious materials in your EYES, NOSE, or MOUTH, which could happen from a splash
    • CUT yourself on something sharp that had infectious material on it (e.g. a razor blade used to chop samples)
  • Disposing of Biohazards
    • Tissues and samples: put these in the specially-marked red biohazard bags. If the sample is particularly wet, seal the bag and put it in another bag to prevent leaks.
    • Sharps (broken glass, razor blades, etc): set up a special “Sharps” container and label it. Any puncture-resistant container will work, such as a heavy plastic bottle with a screw on lid like a laundry detergent bottle.
  • Emergencies:
    • Cuts and punctures should be washed well with soap and water for several minutes.
    • Splashes to the face should be washed with plenty of running water and soap.
    • Splashes to the eyes or mouth should be rinsed with plenty of water or saline.
    • Treat exposures immediately and then contact a health care professional.
  • Biohazard Spills
    • If the spill is liquid, absorb it with paper towels
    • Saturate the absorbent material with household bleach
    • Wait 15 minutes to decontaminate
    • Wearing gloves, put everything into a biohazard bag
    • Clean the area with bleach or disinfectant; dispose of the paper towels in the biohazard bag
    • Check with your school for specific decontamination procedures
  • Good Biosafety Practices:
    • Never remove anything from the sharps container! When it is full, seal it securely and dispose of it in a way that others won’t be injured by it (like the janitor).
    • If something is both sharp and biohazardous, dispose of it as a sharp.

General Good Practices

  • No horseplay or roughhousing in the lab
  • Do not combine chemicals unless instructed to do so
  • Lab equipment is sensitive and expensive; only use for intended purposes
  • No food
    • No gum or candy
    • Don’t use the microwave, fridge or freezer to prepare or store food
    • Dispose of food wrappers and cups before entering the lab
    • Do not apply cosmetics (e.g. lipbalm) in the lab
  • Handwashing prevents the spread of hazardous substances to others
    • Wash your hands before leaving the lab area
    • Wash your hands even if you had gloves on
    • Wash your hands even if you are leaving the area for a few minutes
  • Emergencies
    • There should be a sign in the lab with clear instructions on what to do in case of
      • Fire
      • Chemical spill
      • Biological spill
      • Injury
    • It should include the names and contact information in case of emergency and after-hours emergency

B.E.A.T. Box Specific Hazards

  • Extraction Kit
    • Contains chemicals that dissolve proteins and break cells open; irritating to skin and membranes
  • SYBR Green
    • Potential mutagen. Avoid getting on skin. Label staining container and staining area so people know not to handle items in this area without gloves. SYBR is light-sensitive, cover container with aluminum foil.
  • TBE Buffer
    • Considered non-hazardous, but can be irritating to skin and hazardous if swallowed. Be sure to label the bottle containing dilute buffer.
  • Agarose
    • Non-hazardous, but is a dusty powder so avoid inhaling.
  • Gel electrophoresis poses a serious electrocution risk
    • Never touch the buffer or gel while the current is running
    • Turn off the power supply and unplug the cables before opening a gel rig.
  • Ethanol should be treated like a chemical and stored in a locked cabinet.
    • This is the same alcohol found in beer, wine, etc.
    • 200 proof laboratory alcohol is
      • very hazardous if swallowed
      • extremely flammable
      • often contains BENZENE, which is poisonous.
  • Distilled water and DEPC water are super-pure water
    • Non-hazardous
    • Important not to contaminate this water
  • Freezer, Refrigerator, and Microwave
    • Never use for food storage or preparation
    • Food can become contaminated with hazardous materials
    • Reagents and samples can become contaminated by food and drink