Laboratory Safety and Infection Control

Laboratory Safety

• Laboratory safety is crucial to ensure the health and safety of workers and researchers in laboratory settings.
• Laboratories can be hazardous environments with potential risks, including chemical spills, fires, explosions, and exposure to hazardous substances.

Infection Control

• Infection: when a microorganism invades the body, multiplies, and causes injury or disease.
• Microbes include bacteria, fungi, protozoa, and viruses.
• Pathogen: a microbe capable of causing disease.
• Types of infections:
  • Communicable: able to be spread from person to person.
  • Nosocomial and healthcare-associated infections (HAIs): infections acquired in hospitals and other healthcare settings, causing 1.7 million HAIs and 99,000 associated deaths each year.
• Chain of Infection:
  1. Infectious (causative) agent: pathogenic microbe responsible for causing an infection.
  2. Reservoir: source of infectious agent, including humans, animals, food, water, soil, and equipment.
  3. Exit pathway: way an infectious agent leaves a reservoir host, including secretions, exudates, tissue specimens, blood, feces, and urine.
  4. Means of transmission: airborne, contact, direct, indirect, droplet, vector, and vehicle.
  5. Entry pathway: way an infectious agent enters a susceptible host, including body orifices, mucous membranes, and breaks in skin.
  6. Susceptible host: someone with a decreased ability to resist infection, influenced by factors such as age, health, and immune status.
• Breaking the Chain of Infection:
  • Hand washing
  • Nutrition, rest, and stress reduction
  • Immunization
  • Insect and rodent control
  • Isolation procedures
  • Decontamination of surfaces and instruments
  • Disposal of sharps and infectious waste
  • Use of gloves, gowns, masks, and respirators
  • Needle safety devices
• Infection-Control Program:
  • Protects patients, employees, visitors, and others.
  • Breaks the chain of infection.
  • Monitors and collects data on all infections occurring in the institution.
  • Institutes special precautions in the event of outbreaks.
  • Components: employee screening and immunization, evaluation and treatment, and surveillance.

Biosafety

• Biohazard: any material or substance harmful to health, identified by a biohazard symbol.
• Biohazard exposure routes:
  • Airborne
  • Ingestion
  • Nonintact skin
  • Percutaneous (through the skin)
  • Permucosal (through mucous membranes)
• Blood-Borne Pathogen (BBP):
  • Hepatitis B virus (HBV) and hepatitis D virus.
  • Best defense: HBV vaccination.
  • HBV exposure hazards: present in blood and other body fluids, can survive up to a week on objects, and transmitted via needlesticks, sexual contact.
• Exposure Control Plan:
  • Written and reviewed at least annually.
  • Nonmanagerial employees with risk of exposure are involved in identification, review, and selection.
• BBP Exposure Routes:
  • Skin pierced by a contaminated needle or sharp object.
  • Blood or other body fluid splashes in eyes, nose, or mouth.
  • Blood or other body fluid contacts cut, scratch, or abrasion.
  • A human bite breaks the skin.
• Exposure Incident Procedure:
  • Needlestick or other sharps injury: carefully remove shards of glass or other objects, wash site with soap and water for at least 30 seconds.
  • Mucous membrane exposure: flush site with water or sterile saline for at least 10 minutes, use eyewash station if available, and remove contact lenses as soon as possible and disinfect them.
  • Report incident to immediate supervisor and provider for evaluation, treatment, and counseling.

Electrical Safety

• Actions to take if electrical shock occurs:
  • Shut off the source of electricity.
  • Use a nonconducting item to remove the source of electricity from the victim.
  • Call for medical assistance.
  • Start cardiopulmonary resuscitation if indicated.
  • Keep the victim warm.

Fire Safety

• All employees should know:
  • Procedures to follow in case of fire.
  • Location of fire extinguishers and how to use them.
  • Location of fire blankets or heavy towels and how to use them.
  • Location of emergency exits and evacuation routes.
• Components needed for fire to occur:
  • Fuel: combustible material.
  • Heat: raises the temperature of the material until ignition.
  • Oxygen: to maintain combustion.
  • Chemical reaction: produces fire.
• Keep components apart to prevent fire.
• Classes of Fire:
  • Class A: ordinary combustible materials (wood, paper), require water or water-based solutions to extinguish.
  • Class B: flammable liquids and vapors (paint, oil, grease, gasoline), require blocking oxygen or smothering to extinguish.
  • Class C: electrical equipment, require nonconducting agents to extinguish.
  • Class D: combustible or reactive metals (sodium, potassium, magnesium, lithium), require dry powder agents or sand to extinguish.
  • Class K: high-temperature cooking oils, grease, or fats, require agents that prevent splashing and cool and smother the fire.

Chemical Safety

• General Rules:
  • Always wear PPE.
  • Clean up chemical spills properly.
  • Never store chemicals above eye level or indiscriminately mix chemicals together.
  • Never add water to acid.
• OSHA Hazard Communication (HazCom) Standard:
  • HazCom labeling requirements: statement of warning ("danger" or "poison"), statement of hazard (toxic, flammable, combustible), precautions to eliminate risk, and first aid measures for spills or other exposure.
  • Material Safety Data Sheets: provide general, precautionary, and emergency information on the product.
• Spill cleanup kit: necessary for cleaning up chemical spills.