CHEM 123 LAB - Week 2: Laboratory Safety Flashcards

Regulatory Frameworks and Occupational Safety Acts

• Occupational Safety and Health Act (OSHA):

  • Enacted by the United States Congress in 1970 as Public Law 91-596.
  • Main Goal: Provide all employees with a safe work environment.
  • Occupational Safety and Health Administration (OSHA) Authority: Authorized to conduct mandatory on-site inspections to determine whether employers comply with established safety standards.

• Key OSHA Standards Regulating Laboratory Safety:

  • Blood-borne Pathogen Standard
  • Formaldehyde Standard
  • Laboratory Standard
  • Hazard Communication Standard
  • Respiratory Standard
  • Air Contaminants Standard
  • Personal Protective Equipment Standard

Biological Safety, Infection Control, and Precautions

• Blood-borne Pathogen Standard:

  • Applies to all occupational exposures to blood or other potentially infectious materials (OPIM) in any work environment.
  • Mandates Universal Precautions and Personal Protective Equipment (PPE).
  • Requires the establishment and maintenance of a formal written Exposure Control Plan.
  • Sets protocols for decontamination and safe handling of clinical specimens.
  • Mandates Hepatitis B Virus (HBV) vaccination availability for exposed personnel.

• Chain of Transmission and Biological Risk Control:   

  • Interventions targeting the Source:
  • Hand washing
  • Biohazardous waste disposal
  • Decontamination protocols
  • Specimen bagging
  • Interventions targeting Transmission:
  • Hand washing
  • Personal Protective Equipment (PPE)
  • Aerosol prevention measures
  • Use of sterile/disposable equipment
  • Pest control programs
  • Interventions targeting the Host:
  • Standard precautions
  • Immunization
  • Maintenance of a healthy lifestyle
  • Exposure control plan implementation
  • Postexposure prophylaxis

• Universal Precautions (UP):

  • Instituted by the Centers for Disease Control and Prevention (CDC) in 1987.
  • Principle: All patients are considered potential carriers of blood-borne pathogens.
  • Core Directives:
  • Wear gloves whenever collecting or handling blood and body fluids contaminated with blood.
  • Wear face shields or eye/face protection when there is a risk of blood splashing onto mucous membranes.
  • Dispose of all needles and sharp objects immediately into puncture-resistant containers.
  • CDC Limitation/Exclusion: Excluded urine and body fluids not visibly contaminated by blood from mandatory UP, despite the reality that specimens can contain significant invisible microscopic blood.

• Body Substance Isolation (BSI) Guidelines:

  • Developed as a modification of Universal Precautions to address non-visible blood risks.
  • Broadened Scope: Considers all body fluids and moist body substances to be potentially infectious, not just blood-borne pathogens.
  • Protocol: Personnel must wear gloves at all times when encountering moist body substances.
  • Disadvantage: BSI guidelines do not explicitly recommend handwashing following glove removal unless visual contamination is present.

• Standard Precautions:

  • Modern synthesis incorporating key elements of UP and BSI:
  • Hand washing
  • Glove usage
  • Mask, eye protection, and face shield usage
  • Gown usage
  • Proper handling of patient care equipment
  • Environmental surface control
  • Linen handling
  • Occupational health and blood-borne pathogen management
  • Patient placement considerations

Chemical Safety, Hazard Communication, and Regulations

• Hazard Communication Standard (Right to Know Law):

  • Regulated under Toxic and Hazardous Substances laws.
  • Purpose: Ensure that hazards of all chemicals used in the workplace are evaluated and that hazard information is transmitted directly to employers and employees.
  • Mandatory Clinical Laboratory Compliance Actions:
  • Plan and implement a comprehensive written hazard communication program.
  • Obtain Safety Data Sheets (SDS) / Material Safety Data Sheets (MSDS) for all hazardous chemicals.
  • Educate and train all employees regarding chemical hazards.
  • Maintain standard hazard warning labels on containers received or filled on-site.

• Material Safety Data Sheet (MSDS) Required Sections:

  1. Product name and identification
  2. Hazardous ingredients
  3. Permissible exposure limit (PEL)
  4. Physical and chemical data
  5. Health hazard data and carcinogenic potential
  6. Primary routes of entry
  7. Fire and explosion hazards
  8. Reactivity data
  9. Spill and disposal procedures
  10. Personal Protective Equipment (PPE) recommendations
  11. Handling instructions
  12. Emergency and first aid procedures
  13. Storage and transportation precautions
  14. Chemical manufacturer's name, address, and telephone number
  15. Special information section

• OSHA Laboratory Standard:

  • Enacted to address specific gaps and shortcomings of the general Hazard Communication Standard in laboratory settings.
  • Mandates the appointment of a qualified Chemical Hygiene Officer (CHO).
  • Requires the formulation and enforcement of a formal Chemical Hygiene Plan (CHP).
  • Chemical Hygiene Plan (CHP) Directives:
  • Must describe explicit procedures to protect workers against teratogens, carcinogens, and other acute/chronic toxic chemicals.
  • Must detail engineering controls, PPE requirements, safe work practices, administrative controls, and medical surveillance/consultation provisions.

NFPA 704 Hazard Identification System

• Blue Diamond — Health Hazard:

  • Level 4: Deadly
  • Level 3: Extreme Danger
  • Level 2: Hazardous
  • Level 1: Slightly Hazardous
  • Level 0: Normal Material

• Red Diamond — Fire Hazard (Flash Points):

  • Level 4: Below $73\,^\circ\text{F}$ ($23\,^\circ\text{C}$)
  • Level 3: Below $100\,^\circ\text{F}$ ($38\,^\circ\text{C}$)
  • Level 2: Above $100\,^\circ\text{F}$ ($38\,^\circ\text{C}$) not exceeding $200\,^\circ\text{F}$ ($93\,^\circ\text{C}$)
  • Level 1: Above $200\,^\circ\text{F}$ ($93\,^\circ\text{C}$)
  • Level 0: Will not burn

• Yellow Diamond — Reactivity / Instability:

  • Level 4: May Detonate
  • Level 3: Shock & Heat may detonate
  • Level 2: Violent Chemical change
  • Level 1: Unstable if heated
  • Level 0: Stable

• White Diamond — Specific Hazard Symbols:

  • ACID: Acid
  • ALK: Alkali
  • COR: Corrosive
  • OXY: Oxidizer
  • Radioactive Symbol: Radioactive
  • $\text{W}$ with horizontal line (\text{\mathbb{W}}/$\cancel{\text{W}}$): Use No Water

Waste Management and Environmental Regulations

• Ecological Solid Waste Management Act of 2000 (Republic Act 9003):

  • Formulated by the Department of Environment and Natural Resources (DENR).
  • Color-Coded Waste Receptacle Standards:
  • Green Container: Biodegradable waste (e.g., food wastes, yard wastes).
  • Red Container: Non-biodegradable / Recyclable waste (e.g., paper, plastic, styrofoam, tin cans, bottles).
  • Blue Container: Non-recyclable / Residual waste (e.g., worn-out rags, ceramics, soiled plastics, candy wrappers).
  • Black Container: Special / Hazardous waste (e.g., used fluorescent bulbs, batteries, spray canisters).

• Other Regulatory Agencies and Environmental Laws:

  • Clean Water Act
  • Resource Conservation and Recovery Act (RCRA)
  • Toxic Substances Control Act (TSCA)
  • Clinical and Laboratory Standards Institute (CLSI): Provides general and infection control guidelines.
  • The Joint Commission (TJC)
  • College of American Pathologists (CAP)
  • National Fire Protection Association (NFPA)

General Laboratory Safety Rules and Safety Equipment

• Core Laboratory Rules:

  • Follow instructions strictly; execute lab procedures only when an instructor is present.
  • Conduct oneself responsibly at all times.
  • Never handle equipment, chemicals, or materials until directed to do so.
  • Prohibit smoking, eating, drinking, or applying cosmetics in the laboratory.
  • Prohibit using lab glassware as containers for food or beverages.
  • Wear shoes made of nonporous materials with closed toes and heels.
  • Perform hand washing between every patient/sample interaction, even if gloves were worn.
  • Discard needles and sharps immediately into puncture-resistant, leak-proof container units.
  • Report all accidents, spills, or injuries to the instructor immediately, regardless of minor appearance.

• Mandatory Laboratory Safety Equipment:   

  • Safety showers
  • Eyewash stations
  • Fire extinguishers
  • Fire blankets, chemical spill kits, and first aid supplies
  • Personal protective eyewear (goggles/face shields)

Laboratory Containment and Primary Barriers

• Chemical Fume Hoods and Biological Safety Cabinets (BSCs):   
  • Fume hoods prevent inhalation of toxic, volatile, or flammable vapors by drawing air away from the user.
  • Biological safety cabinets utilize HEPA filtration to enclose biohazardous aerosols and protect both operator and specimen.

Emergency Decontamination and Spill Protocols

• Biological Spill Clean-up Protocol:

  1. Put on appropriate personal protective equipment (PPE).
  2. Use mechanical devices (e.g., tongs, dustpan) to collect broken glass or sharps; never pick up broken glass by hand.
  3. Absorb the liquid spill using paper towels, gauze pads, or tissues.
  4. Clean the spill surface thoroughly using an aqueous detergent solution.
  5. Disinfect the spill area with an approved laboratory disinfectant or a $10\%$ bleach solution, maintaining appropriate contact time.
  6. Rinse the cleaned site with water.
  7. Dispose of all contaminated cleanup materials into designated biohazard waste containers.

• Concentrated Acid / Base Spill Protocol:

  1. Dilute the spill with water prior to chemical neutralizer application.
  2. Apply chemical neutralizer over the entire spill area:
  • For Acid Spills: Neutralize with Sodium Bicarbonate ($\text{NaHCO}_3$).
  • For Base Spills: Neutralize with Boric Acid ($\text{H}_3\text{BO}_3$).
  1. Absorb the neutralized liquid mixture using absorbent material.
  2. Scrub and cleanse the remaining surface thoroughly with soap and water.

Chemical Hazard Classifications and Carcinogen Regulations

• Chemical Hazard Categories:

  • Flammable / Combustible: Chemicals with defined flash points (temperature at which sufficient vapor is given off to form an ignitable mixture with air).
  • Liquid Examples: Acetone, Benzene, Ethanol, Heptane, Isopropanol, Methanol, Toluene, Xylene.
  • Gases and Solids: Hydrogen gas, paraffin wax.
  • Corrosives: Chemicals defined by a $\text{pH} < 2$ or $\text{pH} > 12.5$. Cause direct destructive injury to skin, eyes, respiratory tract, and gastrointestinal tract.
  • Acidic Examples: Acetic acid, sulfuric acid, nitric acid, hydrochloric acid.
  • Basic Examples: Ammonium hydroxide, potassium hydroxide, sodium hydroxide.
  • Toxic Substances: Includes poisons, irritants, and asphyxiants.
  • Carcinogens: Agents capable of causing cancer.
  • Mutagens and Teratogens: Agents capable of causing chromosomal aberrations and congenital malformations, respectively.
  • Ignitable: Flammables and combustibles.
  • Reactive: Explosives and strong oxidizers.

• OSHA Regulated Carcinogenic Chemicals:

  • Chloromethyl methyl ether
  • Vinyl chloride
  • N-Nitrosodimethylamine
  • Benz[a]pyrene
  • 4-Aminobiphenyl
  • Benzidine
  • 1-Naphthylamine
  • 2-Naphthylamine
  • 4-Nitrobiphenyl
  • Benzene
  • Ethylenimine
  • P-Dimethylaminobenzene
  • $\beta$-Propiolactone
  • Bis(chloromethyl) ether

Chemical Storage Guidelines

• General Storage Rules:
  • Store chemicals in an uncluttered, properly ventilated area away from direct heat sources.
  • Never store chemical containers above eye level.
  • Keep inorganic chemicals separated from organic chemicals (with the explicit exception of Nitric Acid).
  • Store flammable liquids inside certified, fire-rated flammable safety cabinets.
  • Store water-reactive chemicals in dedicated dry environments free from automatic overhead sprinkler systems.

Radiation Safety and Environmental Protection

• Nuclear Regulatory Commission (NRC) Requirements:
  • A official NRC license is mandatory if total accumulated radioactive material exceeds regulatory thresholds.
  • Personnel handling radioactive chemicals must wear radiation exposure tracking devices such as film badges or thermoluminescent dosimeters (TLDs) / ring badges.

Fire Safety, Classification, and Extinguishers

• Chemistry of Fire (Fire Triangle):

  • Fire requires three simultaneous components to initiate and sustain combustion: Fuel, Heat/Ignition Source, and Oxygen (air).

• Classes of Fire and Suitable Extinguishers:   

  • Class A Fires:
  • Material: Ordinary solid combustibles (wood, paper, cloth, rubber, trash, plastics).
  • Extinguishers: Pressurized Water, Multipurpose ABC Dry Chemical, Halotron, Foam.
  • Class B Fires:
  • Material: Flammable liquids, solvents, grease, gasoline, oil, paints, lacquers, oil-based products.
  • Extinguishers: Multipurpose ABC Dry Chemical, Regular BC Dry Chemical, Purple K, Carbon Dioxide ($\text{CO}_2$), Halotron, Foam.
  • Class C Fires:
  • Material: Energized electrical equipment (wiring, controls, motors, switches, machinery, appliances).
  • Extinguishers: Multipurpose ABC Dry Chemical, Regular BC Dry Chemical, Purple K, Carbon Dioxide ($\text{CO}_2$), Halotron.
  • Class D Fires:
  • Material: Combustible/reactive metals (magnesium, sodium, potassium, lithium, titanium).
  • Extinguishers: Metal X, Dry Powder agents (applied by scooping or sprinkling to completely cover the burning material).
  • Class K Fires:
  • Material: Combustible cooking media (cooking oils and fats in commercial kitchens).
  • Extinguishers: Wet Chemical agents.

• Fire Extinguisher Operation Protocol (PASS):

  • Pull the locking pin.
  • Aim the nozzle at the base of the fire.
  • Squeeze the operating trigger.
  • Sweep the nozzle side to side across the base of the flame.

Electrical Safety Protocols

• Electrical Safety Directives:
  • Operate exclusively explosion-proof equipment in volatile or hazardous atmospheres.
  • Exercise extreme caution when working with high-voltage equipment (e.g., electrophoresis power supply systems).
  • Ensure all electrical devices utilize standard grounded three-pronged plugs.
  • Inspect cords regularly; never use devices with frayed or damaged electrical wiring.
  • Report equipment malfunctions immediately.
  • Never perform maintenance or repair on live, energized electrical equipment.
  • Schedule annual technical inspections of lab equipment to verify ground integrity and check for current leakage.

Laboratory Pipetting Instruments and Practices

• Types of Pipettes:
  • Transfer / Pasteur Pipettes:     
  • Used to transfer small, unmeasured liquid quantities.
  • Typically disposable plastic or glass units.
  • Serological Pipettes:     
  • Plain, narrow tube structure extending directly to the tip with uniform graduations along its total length.
  • Volumetric Pipettes:     
  • Designed for precise volume measurement of liquid solutions.
  • Characterized by a large central bulb with long, narrow glass tubing above and below.
  • Automatic Pipettes / Micropipettes:     
  • Designed to measure and dispense micro-volumes of liquid ranging between $1\,\mu\text{L}$ and $1000\,\mu\text{L}$.
  • Deliver high accuracy and precision.

Pipetting Error Analysis and Meniscus Reading

• Common Pipetting Errors:

  • Utilizing uncalibrated micropipettes.
  • Using contaminated liquid solutions or reusable disposable tips.
  • Aspirating fluids too rapidly.
  • Pipetting at an incline, causing liquid volume variance.

• Impact of Immersion Depth and Angle on Measurement Inaccuracy:   

  • Immersion depth and tilt angle errors disproportionately affect micro-volumes (e.g., $1\text{--}10\,\mu\text{L}$ pipettes):
  1. Vertical position, $1\,\text{cm}$ tip immersion: Inaccuracy rate = $0.2\text{--}0.4\%$.
  2. Vertical position, $3\,\text{cm}$ tip immersion: Inaccuracy rate = $0.6\text{--}0.8\%$.
  3. $30\text{--}40^\circ$ tilt angle, $3\text{--}4\,\text{cm}$ tip immersion: Inaccuracy rate = $1\text{--}1.2\%$.

• Meniscus Reading Guidelines:   

  • Concave / Lower Meniscus: Read at the lowest horizontal point of the liquid curvature at eye level (standard for clear aqueous liquids).
  • Convex / Upper Meniscus: Read at the highest outer edge level (used for opaque liquids or specialized calibrations).