CRCST Exam Prep Practice Exercise 1
Questions With 100% Pass
/. Dynamic air removal: exposure time for any wrapped item at 275 degrees. - Answer-3
minutes
/.What is the correct percentage of relative humidity for steam sterilization? - Answer-
97%-100%
/.What are the 4 cycles of steam sterilization? - Answer-Conditioning, exposure,
exhaust, drying
/.Which low-temp sterilization method requires monitoring? - Answer-Ethylene oxide
/.How does ethylene oxide kill microbes? - Answer-By a process called alkylation.
/.How do ozone and hydrogen peroxide kill microbes? - Answer-By a process called
oxidation.
/.Discuss sterilization parameters for ethylene oxide (concentration, temp, humidity,
exposure time, aeration time) - Answer-Concentration: 450-1200 mg/l
Temp: 98-145 degrees F
Exposure time: 1-6 hours
Humidity: 40-80%
Aeration time: 8-12 hours at 122-140 degrees F
/.What is the microorganism of choice for ethylene oxide sterilization? - Answer-Bacillus
atrophaeus
/.What are the five phases of gas plasma sterilization? - Answer-Vacuum, injection,
diffusion, plasma, vent
/.Which materials are not recommended for use in hydrogen peroxide sterilization
method She? - Answer-Cellulose, muslin wraps
/.What is the microorganism of choice for hydrogen peroxide gas plasma sterilization? -
Answer-Geobacillus stearothermophilus
/.Discuss hydrogen peroxide gas plasma sterilization parameters (time, temp,
concentration, vacuum level, plasma) - Answer-Time: 24-75 minutes
Temp: less than 131 degrees F
Concentration: 59-95%
, Vacuum level: auto controlled
Plasma: auto controlled
/.What are the 4 cycles for vaporized hydrogen peroxide systems? - Answer-
Conditioning, leak test, sterilization, aeration
/.Discuss vaporized hydrogen peroxide sterilization parameters (temp, concentration,
time, other). - Answer-Temp: less than 122 degrees F
Concentration: 59%
Time: 28-55 minutes
Other: preset cycles
/.What is the microorganism of choice for VHP? - Answer-Geobacillus
stearothermophilus
/.Discuss ozone sterilization parameters (temp, concentration, humidity, time). - Answer-
Temp: 87.4-97 degrees F
Concentration: 59%
Humidity: 85-100%
Time: 4.5 hours
/.What is the microorganism of choice for OzOne sterilization? - Answer-Geobacillus
stearothermophilus
/.What materials cannot be processed in VHP or gas plasma sterilizers? - Answer-
Cellulose, linens, liquids, powders
/.What materials cannot be processed in an ozone sterilizer? - Answer-Rubber, latex,
textiles, copper, brass, bronze, zinc, nickel.
/.How many air exchanges are required in the decontamination area? - Answer-No less
that 10 per hour.
/.What are the parameters for relative humidity in the decontamination area? - Answer-
30-60%
/.What should the temperature range be in the decontamination are? - Answer-60-65
degrees F
/.What is the temperature range for water in the decontamination area? - Answer-80-
110 degrees F
/.This temperature should not be exceeded when using enzymatic cleaners. - Answer-
140 degrees F
/.What is the pH of neutral detergents? - Answer-6-8
Questions With 100% Pass
/. Dynamic air removal: exposure time for any wrapped item at 275 degrees. - Answer-3
minutes
/.What is the correct percentage of relative humidity for steam sterilization? - Answer-
97%-100%
/.What are the 4 cycles of steam sterilization? - Answer-Conditioning, exposure,
exhaust, drying
/.Which low-temp sterilization method requires monitoring? - Answer-Ethylene oxide
/.How does ethylene oxide kill microbes? - Answer-By a process called alkylation.
/.How do ozone and hydrogen peroxide kill microbes? - Answer-By a process called
oxidation.
/.Discuss sterilization parameters for ethylene oxide (concentration, temp, humidity,
exposure time, aeration time) - Answer-Concentration: 450-1200 mg/l
Temp: 98-145 degrees F
Exposure time: 1-6 hours
Humidity: 40-80%
Aeration time: 8-12 hours at 122-140 degrees F
/.What is the microorganism of choice for ethylene oxide sterilization? - Answer-Bacillus
atrophaeus
/.What are the five phases of gas plasma sterilization? - Answer-Vacuum, injection,
diffusion, plasma, vent
/.Which materials are not recommended for use in hydrogen peroxide sterilization
method She? - Answer-Cellulose, muslin wraps
/.What is the microorganism of choice for hydrogen peroxide gas plasma sterilization? -
Answer-Geobacillus stearothermophilus
/.Discuss hydrogen peroxide gas plasma sterilization parameters (time, temp,
concentration, vacuum level, plasma) - Answer-Time: 24-75 minutes
Temp: less than 131 degrees F
Concentration: 59-95%
, Vacuum level: auto controlled
Plasma: auto controlled
/.What are the 4 cycles for vaporized hydrogen peroxide systems? - Answer-
Conditioning, leak test, sterilization, aeration
/.Discuss vaporized hydrogen peroxide sterilization parameters (temp, concentration,
time, other). - Answer-Temp: less than 122 degrees F
Concentration: 59%
Time: 28-55 minutes
Other: preset cycles
/.What is the microorganism of choice for VHP? - Answer-Geobacillus
stearothermophilus
/.Discuss ozone sterilization parameters (temp, concentration, humidity, time). - Answer-
Temp: 87.4-97 degrees F
Concentration: 59%
Humidity: 85-100%
Time: 4.5 hours
/.What is the microorganism of choice for OzOne sterilization? - Answer-Geobacillus
stearothermophilus
/.What materials cannot be processed in VHP or gas plasma sterilizers? - Answer-
Cellulose, linens, liquids, powders
/.What materials cannot be processed in an ozone sterilizer? - Answer-Rubber, latex,
textiles, copper, brass, bronze, zinc, nickel.
/.How many air exchanges are required in the decontamination area? - Answer-No less
that 10 per hour.
/.What are the parameters for relative humidity in the decontamination area? - Answer-
30-60%
/.What should the temperature range be in the decontamination are? - Answer-60-65
degrees F
/.What is the temperature range for water in the decontamination area? - Answer-80-
110 degrees F
/.This temperature should not be exceeded when using enzymatic cleaners. - Answer-
140 degrees F
/.What is the pH of neutral detergents? - Answer-6-8
