B250C MODULE 3 EXAM SCRIPT 2026
COMPLETE ANSWERS VERIFIED
◉ what factors determine the level of cleanliness required for a
particular fomite. Answer: - application for the item (medical = more
cleanliness)
- level of resistance to antimicrobial treatments by potential
pathogens
◉ biosafety level 1. Answer: - microbes not known to cause disease
and pose minimal risk to workers and env't
- ex: nonpathogenic strain of E. coli or B. subtilis
◉ biosafety level 2. Answer: - microbes indigenous and pose
moderate risk to workers and env't
- may require restricted access, PPE, safety cabinets
- ex: S. aureus or Salmonella, viruses like hepatitis, MMR
,◉ biosafety level 3. Answer: - microbes indigenous or exotic and
serious or potentially lethal disease through respiratory
transmission
- must wear respirator and use biological safety cabinet, self-closing
door and directional airflow required
- ex: M. tuberculosis, B. anthracis, West Nile Virus, HIV
◉ biosafety level 4. Answer: - microbes dangerous and exotic, pose
high risk of aerosol-transmitted infections that are fatal without
treatment/vaccine
- must change clothes after entering lab, shower and decontaminate
all material upon exiting,
- must wear full body suit (with higher pressure than outdoor air) or
have a designated air supply
- few labs at this level
- ex: Ebola and Marburg viruses
,◉ what factors influence determination of biosafety levels?. Answer:
- agent's infectivity
- ease of transmission
- potential disease severity
- type of work being done with agent
◉ methods of microbial growth control. Answer: - sterilization -
removal or killing of all microbes and endospores (high heat,
pressure, filtration, chemicals)
- disinfection - eliminates most microbes on fomite (vinegar,
chlorine chemicals)
- decontamination - sanitizes (soaps, detergents, commercial
dishwashers)
- antisepsis - prevents chance of infection, degree of cleanlines
depends on item (hydrogen peroxide, isopropyl alcohol)
◉ how are critical items different from semicritical items in
disinfection?. Answer: critical items will penetrate tissues and must
, be held to a higher degree of cleanliness, semi-critical items only
contact mucous membranes
◉ -cide suffix v. -static suffix. Answer: -cide refers to destroying or
killing all spores and microbes
-static refers to preventing the growth of an organism
◉ microbial death. Answer: - permanent loss of reproductive
capabilities
- rate of death is usually constant over time
◉ what factors influence efficacy of agents causing microbial death?.
Answer: - number of microbes (more = harder to kill)
- environment (could inhibit chemical agents)
- time of exposure (longer is usually better)
- concentration of the agent (more = better, but more could also be
toxic)
- microbial characteristics (virus, bacteria, fungi, spores)
◉ moist heat requires _______ exposure time than dry heat.. Answer:
shorter
COMPLETE ANSWERS VERIFIED
◉ what factors determine the level of cleanliness required for a
particular fomite. Answer: - application for the item (medical = more
cleanliness)
- level of resistance to antimicrobial treatments by potential
pathogens
◉ biosafety level 1. Answer: - microbes not known to cause disease
and pose minimal risk to workers and env't
- ex: nonpathogenic strain of E. coli or B. subtilis
◉ biosafety level 2. Answer: - microbes indigenous and pose
moderate risk to workers and env't
- may require restricted access, PPE, safety cabinets
- ex: S. aureus or Salmonella, viruses like hepatitis, MMR
,◉ biosafety level 3. Answer: - microbes indigenous or exotic and
serious or potentially lethal disease through respiratory
transmission
- must wear respirator and use biological safety cabinet, self-closing
door and directional airflow required
- ex: M. tuberculosis, B. anthracis, West Nile Virus, HIV
◉ biosafety level 4. Answer: - microbes dangerous and exotic, pose
high risk of aerosol-transmitted infections that are fatal without
treatment/vaccine
- must change clothes after entering lab, shower and decontaminate
all material upon exiting,
- must wear full body suit (with higher pressure than outdoor air) or
have a designated air supply
- few labs at this level
- ex: Ebola and Marburg viruses
,◉ what factors influence determination of biosafety levels?. Answer:
- agent's infectivity
- ease of transmission
- potential disease severity
- type of work being done with agent
◉ methods of microbial growth control. Answer: - sterilization -
removal or killing of all microbes and endospores (high heat,
pressure, filtration, chemicals)
- disinfection - eliminates most microbes on fomite (vinegar,
chlorine chemicals)
- decontamination - sanitizes (soaps, detergents, commercial
dishwashers)
- antisepsis - prevents chance of infection, degree of cleanlines
depends on item (hydrogen peroxide, isopropyl alcohol)
◉ how are critical items different from semicritical items in
disinfection?. Answer: critical items will penetrate tissues and must
, be held to a higher degree of cleanliness, semi-critical items only
contact mucous membranes
◉ -cide suffix v. -static suffix. Answer: -cide refers to destroying or
killing all spores and microbes
-static refers to preventing the growth of an organism
◉ microbial death. Answer: - permanent loss of reproductive
capabilities
- rate of death is usually constant over time
◉ what factors influence efficacy of agents causing microbial death?.
Answer: - number of microbes (more = harder to kill)
- environment (could inhibit chemical agents)
- time of exposure (longer is usually better)
- concentration of the agent (more = better, but more could also be
toxic)
- microbial characteristics (virus, bacteria, fungi, spores)
◉ moist heat requires _______ exposure time than dry heat.. Answer:
shorter
