General Lab Safety Notes

General Lab Safety

Radiation Hazards

• Hazards from radiation can occur from external sources or radioactive materials entering the body.
• The effects depend on:
  • Dose
  • Duration of exposure
  • Type of organ exposed

Radiation Damage

• Some radiation can cause damage above a certain limit, usually 1 sievert (Sv).
• Damage includes:
  • Radiation dermatitis
  • Cataract
  • Organ failure
  • Radiation sickness
• Other radiation types increase damage risk with increased doses.
  • Example: Cancer (radiation-induced mutation)
• Radioactive leaks can cause:
  • Rise in mutation rates
  • Cancer (leukemia)
  • Birth defects
  • Hereditary diseases
• Cancer usually develops years after exposure.

Controlling Radiation Damage

• Limit exposure.
• Recommendations by The International Commission of Radiation Protection:
  • Avoid unnecessary personnel radiation exposures.
  • Keep occupational exposures as low as possible.
  • Do not exceed dose limits.
• Principle: ALARA - As Low As Reasonably Achievable.

Working with Radioactive Material

• Requirements before working with radioactive material:
  1. Contact the Radiation Safety Officers for approval.
  2. Attend “Radiation Management Training”.
  3. Obtain a Radiation Monitoring Badge.
  4. Work using SOP approved by the Department Radiation Safety Officer.
• Familiarize yourself with:
  • The nature of the radiation emitted (alpha, beta, gamma, etc.)
  • Tolerable levels of radiation permissible for both short and long term exposure.
• Distance from the radioactive source is the most effective way of reducing exposure.
• NEVER eat, drink, smoke, or apply cosmetics while working with radioactive materials.
• NEVER mouth pipette radioactive materials; use a safety device.
• Work with appropriate shielding:
  • Lead blocks for primary source $^{125}I$ (gamma-emitters)
  • Perspex for $\beta$-emitters.
• Cover working areas with Benchcote (Polythene backed absorbent paper).
• Use clearly labeled plastic trays to hold radioactive samples, pipettes, glassware, etc.
• Mop up all spillages immediately using paper towels.
• Wear disposable rubber or polythene gloves while handling isotopes.
• Wear a film badge.
• Monitor radioactivity before and after every experiment using a hand-held monitor where relevant (e.g. $^{32}P$, $^{125}I$, $^{35}S$) or random swabs (e.g. $^{3}H$).

Irradiation of Internal Organs and Tissues

• May occur due to active materials entering the body by:
  • DIRECT SKIN IRRADIATION
  • INHALATION
    • Depending on particle size, material may lodge in different areas (e.g., large particles in the nose).
    • Some elements concentrate in specific organs (e.g., $^{125}I$ in thyroid).
  • INGESTION
    • Usually insoluble material will pass through the gut and be excreted.
    • Soluble material will find its way to the whole body or to specific organs.
  • WOUNDS
    • This route operates similarly to ingestion.

Radiation Exposure Limits

• Exposures below 20 mSv per year, averaged over 5 years.
• The effective dose should not exceed 50 mSv in any single year.

Spill Response

• In the event of a spill, it is essential to minimize the spread of contamination.
• Report all spillages immediately to both your supervisor and the Departmental Radiation Officer.
• Isolate the suspected area of contamination.
• Identify, if possible, the type of contamination, i.e., the nuclide(s) involved.
• It may be necessary to use breathing apparatus, protective clothing, or other equipment.
• Determine the area of contamination by monitoring after taking the necessary precautions.
• Starting from the outer edge, decontaminate the area in convenient sectors by wiping and scrubbing.
• Before moving on, ensure that a sector is clean by monitoring.
• Dispose of all radioactive waste according to the appropriate requirement.

General Lab Safety Rules

1. Listen to or read instructions carefully before attempting to do anything.
2. Wear safety goggles to protect your eyes from chemicals, heated materials, or things that might shatter.
3. Notify your lecturer if any spills or accidents occur.
4. After handling chemicals, always wash your hands with soap and water.
5. During lab work, keep your hands away from your face.
6. Tie back long hair.
7. Roll up loose sleeves.
8. Know the location of the fire extinguisher, fire blanket, eyewash station, and first aid kit.
9. Keep your work area uncluttered. Take to the lab station only what is necessary.
10. It is suggested that you wear glasses rather than contact lenses.
11. Never put anything into your mouth during a lab experiment.
12. Clean up your lab area at the conclusion of the laboratory period.
13. Never “horse around” or play practical jokes in the laboratory.

Glassware Safety

1. Chipped or cracked glassware should not be used; show it to the lecturer.
2. Broken glassware should not be disposed of in a classroom trashcan. There is a special glass disposal container for it.
3. When pouring liquids into glassware, make sure the container you are pouring into is resting on a table at least a hands breadth from the edge.
4. Pour down a glass stirring rod to prevent liquids from splattering.
5. If a piece of glassware gets broken, do not try to clean it up by yourself. Notify the teacher.
6. When inserting glass tubing into a rubber stopper, apply a lubricant like glycerin to the glass and use a twisting motion.
7. Do not place hot glassware in water. Rapid cooling may make it shatter.

Chemical Safety

1. Wear protective goggles and a lab apron whenever heating or pouring hazardous chemicals.
2. Never mix chemicals together unless you are told to do so (and then only in the manner specified).
3. Never taste any chemicals (you should never taste anything in the lab).
4. If you need to smell the odor of a chemical, waft the fumes toward your nose with one hand. Do not put your nose over the container and inhale the fumes.
5. Never pour water into a concentrated acid. Acid should be poured slowly into water.
6. Follow the instructions of your teacher when disposing of all chemicals.
7. Wash your hands after handling hazardous chemicals.

Electrical Safety

1. Lay electrical cords where no one can trip on them or get caught in them.
2. Be sure your hands and your lab area are dry before using electrical equipment.
3. Never poke anything into electrical outlets.
4. Unplug cords by pulling the plug and not the cord.
5. Unplug all electrical equipment at the end of the lab period.

Heating Safety

1. Let burners and hotplates cool down before touching them. Test to see if they are cool enough by bringing the back of your hand close to them.
2. Use tongs and/or protective gloves to handle hot objects.
3. Never reach across an open flame or burner.
4. The only type of glassware that may safely be heated is either Kimax or Pyrex.
5. Always point the top ends of test tubes that are being heated away from people.
6. When heating a test tube, move it around slowly over the flame to distribute the heat evenly.
7. Only glassware that is thoroughly dry should be heated.
8. Heat glassware by placing it on a wire gauze platform on a ring stand. Do not hold it in your hand.
9. When lighting a burner, wait until the striker is in place before you turn on the gas.
10. The amount of air can be adjusted by the air supply valve below the tube of the burner. This regulates the flame temperature and color.
11. Never leave a burner or hotplate unattended.

Microscope Handling

1. Always pick up a microscope using both hands, one holding the arm of the microscope and the other supporting its base.
2. Never grab or carry a microscope by its eyepiece.
3. Place the microscope down on a flat surface, such as a tabletop.

Microscope Usage

1. Before using your microscope, look over its various mechanical and optical parts.
2. Familiarize yourself with the operations of the particular model you have.
3. You will want to know what each knob does before operating it to avoid overworking or straining the mechanisms.
4. Use your microscope in a well-lit room or outdoors.
5. If your microscope has built-in light, be sure it is powered on before trying to use it for viewing.
6. When using your microscope at its highest magnification, some models require special preparation of the specimen or lens.

Microscope Cleaning & Care

1. Cleaning frame and stage:
   • Disconnect the plug from the main socket before cleaning.
   • Clean the frame and stage with a soft cloth moistened with a mild detergent solution.
   • Be sure the instrument is dry before using.
2. Cleaning optical parts:
   • Microscope eyepieces and objectives are coated.
   • They should not be wiped dry as dirt or dust may scratch the coating.
   • Always blow loose dust away first.
   • Use cotton swabs or lens tissue moistened with lens cleaner or a small amount of alcohol, then wipe the surface clean with a good quality lens tissue.
   • Solvents such as Xylene should NOT be used as cleaner.