Biosafety in the Lab PDF

Biotechniques (BMS 34010A) Fall semester 2023 -2024 Dr. Tania Tahtouh [email protected] Basic principles: Biosafety in the laboratory What is Lab Safety?  The laboratory setting presents several hazards that must be considered when completing any lab exercise.  Laboratory safet...

Biotechniques (BMS 34010A) Fall semester 2023 -2024 Dr. Tania Tahtouh [email protected] Basic principles: Biosafety in the laboratory What is Lab Safety?  The laboratory setting presents several hazards that must be considered when completing any lab exercise.  Laboratory safety includes procedures that are designed for the protection of all laboratory personnel and the safe use of laboratory equipment.  It also involves strict protocols on the disposal of contaminated materials and chemicals.  Potential Laboratory Hazards  The science laboratory can present a number of hazards to laboratory workers.  These may include corrosive chemicals, sharp tools/glass items, and the use of open flames.  Extreme caution should be used when working with open flames, such as those on a Bunsen burner. Always know when the flame is turned on and pay attention to what materials you have near the flame  Potential Laboratory Hazards  Infectious organisms may also pose a threat to laboratory workers.  In fact, microorganisms are classified into four biosafety levels based on their ease of transmission and pathogenicity. Safety standards in the lab have been developed for working with each biosafety level.  Potential Laboratory Hazards  Most undergraduate laboratories only use BSL 1 organisms, well known organisms that do not usually cause disease in immuno compentent persons.  Working with BSL 4 organisms requires extensive safety measures, such as the personal protective gear shown in this image. These organisms, including Marburg virus and hantavirus, are handled only in specialized laboratories at places like the Centers for Disease Control.  Standard Practices in the Laboratory  Lab coats are an important part of safety when conducting any lab exercise. These can protect a you from contamination by microorganisms or corrosive substances. ▪ They should be long enough in both the sleeves and body to provide good coverage, but not so long that the coat could accidentally get caught on something or be dragged through a hazardous substance. ▪ They should not be so tight that they restrict movements.  REMEMBER: Lab coats are not chemical protection suits! DO immediately remove a lab coat if on fire or there is obvious hazardous contamination.  Standard Practices in the Laboratory  Gloves are also commonly worn to protect the hands from contamination or contact with chemicals/staining reagents.  Not all experiments require the use of gloves, as there may be advantages or disadvantages to their use in the lab.  REMEMBER: Gloves should never touch door handles, elevator buttons, telephones, card swipes, or any surfaces outside of the laboratory. ▪ If you transport materials from labs through common areas, use an ungloved hand to touch common surfaces and a gloved hand to carry the items.  Standard Practices in the Laboratory  Now that you are aware of some potential hazards in the laboratory, let's review some standard safety practices that should always be followed.  First of all, you should never put anything in your mouth while in the laboratory. This includes consuming food, drinking, and chewing gum. You also should never attempt to pipette substances by mouth. This strict rule should be followed to avoid the intake of dangerous substances.  Secondly, you should not apply makeup or adjust contacts while in the laboratory.  Standard Practices in the Laboratory  When conducting lab experiments, the lab bench should be kept clean. You should only have the appropriate lab materials, the lab manual, and a pencil or pen on the lab bench.  Cell phones, purses, book bags, and other personal items should always be safely stowed away from the benchtop.  Do not leave active experiments unattended. Never leave anything that is being heated or is visibly reacting unattended.  Standard Practices in the Laboratory  Before and after every lab experiment, it is good practice to disinfect the benchtop.  This prevents contamination during the exercise and leaves the lab environment clean for the next students.  Standard Practices in the Laboratory  Keep your hands clean. Later in this module, you will also review correct hand washing technique.  Never run in the laboratory.  Do not sit on laboratory benches.  The performance of unauthorized experiments is strictly forbidden. Never work in the laboratory without the supervision.  Standard Practices in the Laboratory  Whenever working with open flames, it is important to tie back long hair and secure loose clothing SAY NO TO: long hair long nails loose clothing Standard Practices in the Laboratory  Goggles, safety glasses or face shields are required when working with UV light and any procedure where aerosols or chemicals may splash into the eyes.  If you wear glasses, safety glasses must be worn over them.  Standard Practices in the Laboratory  During laboratory work, there is a great risk of spilling chemicals on the floor or dropping sharp objects.  Always wear closed toed shoes to avoid contact between chemical substances and the bare skin during spilling accidents. Closed toed shoes may also prevent cuts to the feet in the case of dropping a sharp tool like a dissection scalpel.  Laboratory Safety Equipment  It is also important to know the location of safety equipment in the laboratory classroom.  These include the eyewash and chemical shower used in the event of skin or eye contamination.  A first aid kit and fire extinguisher should also be located somewhere in the laboratory classroom.  Laboratory Safety Equipment  Many institutions have developed chemical hygiene plans, written policies that protect lab personnel from health hazards associated with the use of chemicals in the lab.  Therefore you should always make use of fume hoods or biosafety cabinets as directed by your instructor or the lab exercise procedure.  Lab Emergencies  In the event of a lab emergency, you should immediately notify your instructor. Report any spills, accidents, or injuries.  This includes chemical and biological spills, personal injuries, broken glass, broken laboratory equipment, and other obvious emergencies.  Your instructor will guide you in appropriately dealing with these issues.  Biohazard Bin  Biohazardous waste must be placed into appropriately labeled bins or bags.  This includes non reusable items that have been in contact with infectious organisms or body fluids and animal tissue that is ready to be discarded. Any gloves worn during an exercise involving biohazardous materials should also be placed in this bin.  Items placed in the biohazard bag may be sterilized using an autoclave before they are finally disposed.  Sharps containers & Trash cans  Sharps containers  Non- are to be used for contaminated the disposal of waste paper or broken glass, other trash needles, used should be scalpel blades, used placed into the glass pipettes, or any regular trash other sharp objects. can.  Reusable materials  Reusable materials that require sterilization should be placed in the autoclave after use. ▪ These include items such as bacterial culture tubes, glass rods, and some instruments that must be sterile for use.  Reusable materials that do not require sterilization may be washed in the sink after use. ▪ These include dissection tools and trays, glassware used for nonhazardous materials, and staining trays.  General rules for handling chemicals  Keep chemical containers closed. Dust and vapor may escape from an open container.  Never use a wrong or an unmarked reagent. If you are unsure about the compound, do not use it. Instead, have it disposed of.  Chemical bottles must not be carried by the neck of the bottle, nor next to your body. Suitable carrying arrangements should be employed, e.g. buckets or trolleys.  When pouring from bottles, the label should always face upward to prevent any spillage from destroying the label.  Never put any chemicals in the bottle other than the one indicated on the label.  Special precautions should be taken when handling concentrated acids. Dilution of acids should be performed by pouring the acid into water and stirring continuously.  In some cases, chemicals may be washed down the sink, but in other cases, they must be handled differently.  The Importance of hand washing  Good hand washing technique is an important practice when conducting laboratory exercises, especially in the field of microbiology.  During the lab, your hands may be in contact with infectious organisms, irritating chemicals, stains, and other potentially hazardous materials.  Your hands may also be a source of contamination, leading to poor results.  Therefore, you should wash your hands prior to the lab exercise, after the lab exercise, and any other time your hands have been in contact with potential hazards.  Steps for Correct Hand Washing Technique  According to the Centers for Disease Control, these are the proper steps to wash your hands thoroughly Remove all jewelry, including Wet your hands with clean, items on your wrists. running water and then apply soap. Steps for Correct Hand Washing Technique Rub your hands together to Continue rubbing your hands for at least 20 make a lather. seconds. For a good timing device, sing or hum the “Happy Birthday” song twice. Be sure to scrub the backs of your hands, between your fingers, and under your nails. Steps for Correct Hand Washing Technique Rinse your hands well under Dry your hands using a clean running water. towel or air drying. Metric systems  Units of measurements  The SI system is the form of measurement typically used by scientists.  The United States is the only industrialized nation that has not adapted the SI system. They still use the English system. All Measurement systems have standards. Standards are exact quantities that everyone agrees to use as a basis of comparison  Units of measurements  In the English system you have to remember so many numbers...  12 inches in a foot  3 feet in a yard  5,280 feet in a mile  16 ounces in a pound  4 quarts to a gallon  In the SI System you only have to remember one number. ▪ The SI System is based on the number 10.  Units of measurements The SI System uses the following prefixes  This system works with any SI measurement.  It is the same system regardless if you are measuring length, mass, or volume.  All measurements need a number and a unit! Micro 1/1000000 Units of measurements References  NIH: Safe Laboratory Practices & Procedures. https://ors.od.nih.gov/sr/dohs/safety/laboratory/Pages/student_goodlab.aspx  CDC: School Chemistry Laboratory Safety Guide (2006). https://www.cdc.gov/niosh/docs/2007-107/pdfs/2007-107.pdf