IICRC OCT Course - Practice Questions
and Answers Latest Version (2025/2026)
Already Graded A
What does the acronym OCT stand for in the IICRC certification?
✔✔ Odor Control Technician
What is the primary cause of persistent odors in a structure after a fire?
✔✔ Smoke residues and soot particles embedded in surfaces
What is the first step in odor removal?
✔✔ Identify and eliminate the source of the odor
Why is ventilation important in odor control?
✔✔ It helps remove airborne contaminants and speeds up deodorization.
What type of odor neutralization method uses ozone?
✔✔ Oxidation
1
,Why should ozone generators be used with caution?
✔✔ High levels can be harmful to humans and pets.
How does activated charcoal help with odor control?
✔✔ It absorbs and traps odor molecules from the air.
What is the main function of a hydroxyl generator in odor control?
✔✔ It neutralizes odors using hydroxyl radicals.
How does thermal fogging work to remove odors?
✔✔ It recreates the penetration of smoke and distributes deodorizing particles.
Why is it important to clean surfaces before applying deodorizers?
✔✔ Dirt and residues can block the deodorizer from reaching the odor source.
What is a common cause of musty odors in buildings?
✔✔ Mold and mildew growth due to moisture problems.
2
,Why is negative air pressure used during odor removal?
✔✔ To prevent odors from spreading to unaffected areas.
What is the most effective way to remove pet urine odors?
✔✔ Use enzyme-based cleaners to break down urine compounds.
How do air scrubbers help in odor removal?
✔✔ They filter out airborne odor particles and contaminants.
Why is HEPA filtration useful in odor remediation?
✔✔ It captures tiny odor-causing particles and airborne contaminants.
What is the purpose of sealing surfaces after odor removal?
✔✔ To prevent residual odors from escaping and re-contaminating the air.
How do absorbent powders help in odor removal?
✔✔ They soak up and neutralize liquid-based odor sources.
3
, Why should HVAC systems be inspected during odor remediation?
✔✔ They can distribute odors and contaminants throughout a building.
How does humidity affect odor intensity?
✔✔ Higher humidity can amplify and reactivate odors.
What is the best way to neutralize smoke odors from upholstery?
✔✔ Deep cleaning followed by deodorization using thermal fogging or ozone.
How does an enzymatic cleaner work on organic odors?
✔✔ It breaks down odor-causing bacteria at a molecular level.
What should be done before using chemical deodorizers?
✔✔ Test a small area to ensure compatibility with the surface.
Why is it important to identify the odor source before treatment?
✔✔ Treating the symptom without removing the source will not eliminate the odor.
4
and Answers Latest Version (2025/2026)
Already Graded A
What does the acronym OCT stand for in the IICRC certification?
✔✔ Odor Control Technician
What is the primary cause of persistent odors in a structure after a fire?
✔✔ Smoke residues and soot particles embedded in surfaces
What is the first step in odor removal?
✔✔ Identify and eliminate the source of the odor
Why is ventilation important in odor control?
✔✔ It helps remove airborne contaminants and speeds up deodorization.
What type of odor neutralization method uses ozone?
✔✔ Oxidation
1
,Why should ozone generators be used with caution?
✔✔ High levels can be harmful to humans and pets.
How does activated charcoal help with odor control?
✔✔ It absorbs and traps odor molecules from the air.
What is the main function of a hydroxyl generator in odor control?
✔✔ It neutralizes odors using hydroxyl radicals.
How does thermal fogging work to remove odors?
✔✔ It recreates the penetration of smoke and distributes deodorizing particles.
Why is it important to clean surfaces before applying deodorizers?
✔✔ Dirt and residues can block the deodorizer from reaching the odor source.
What is a common cause of musty odors in buildings?
✔✔ Mold and mildew growth due to moisture problems.
2
,Why is negative air pressure used during odor removal?
✔✔ To prevent odors from spreading to unaffected areas.
What is the most effective way to remove pet urine odors?
✔✔ Use enzyme-based cleaners to break down urine compounds.
How do air scrubbers help in odor removal?
✔✔ They filter out airborne odor particles and contaminants.
Why is HEPA filtration useful in odor remediation?
✔✔ It captures tiny odor-causing particles and airborne contaminants.
What is the purpose of sealing surfaces after odor removal?
✔✔ To prevent residual odors from escaping and re-contaminating the air.
How do absorbent powders help in odor removal?
✔✔ They soak up and neutralize liquid-based odor sources.
3
, Why should HVAC systems be inspected during odor remediation?
✔✔ They can distribute odors and contaminants throughout a building.
How does humidity affect odor intensity?
✔✔ Higher humidity can amplify and reactivate odors.
What is the best way to neutralize smoke odors from upholstery?
✔✔ Deep cleaning followed by deodorization using thermal fogging or ozone.
How does an enzymatic cleaner work on organic odors?
✔✔ It breaks down odor-causing bacteria at a molecular level.
What should be done before using chemical deodorizers?
✔✔ Test a small area to ensure compatibility with the surface.
Why is it important to identify the odor source before treatment?
✔✔ Treating the symptom without removing the source will not eliminate the odor.
4
