CBIC Environmental Cleaning 2 — Questions and Answers
Question 1: Which EPA registration category must a disinfectant meet to be considered appropriate for use on a C. difficile-contaminated surface?
- Hospital-grade disinfectant
- Sporicidal disinfectant (Correct answer)
- Quaternary ammonium compound
- Phenolic disinfectant
Correct answer: Sporicidal disinfectant
C. difficile forms spores that are resistant to most disinfectants; only EPA-registered sporicidal agents (such as bleach-based products) are effective.
Question 2: When cleaning a patient room after discharge, what is the correct sequence of surfaces to clean?
- Floor first, then high-touch surfaces, then bed
- High-touch surfaces first, then bed, then floor (Correct answer)
- Bed first, then walls, then floor
- Floor first, then walls, then bed
Correct answer: High-touch surfaces first, then bed, then floor
High-touch surfaces should be cleaned first using a top-to-bottom, clean-to-dirty approach, ending with the floor.
Question 3: The term 'contact time' (dwell time) as it relates to disinfectants refers to:
- Time between application and rinsing
- Duration the surface must remain visibly wet for efficacy (Correct answer)
- Time it takes to apply the product evenly
- Time required for the product to dry completely
Correct answer: Duration the surface must remain visibly wet for efficacy
Contact time is the minimum period the surface must remain visibly wet with disinfectant to achieve the labeled level of microbial kill.
Question 4: Which of the following is classified as a non-critical surface in Spaulding's classification scheme?
- Surgical instruments
- Endoscopes used in sterile cavities
- Bedside tables and over-bed tables (Correct answer)
- Urinary catheters
Correct answer: Bedside tables and over-bed tables
Non-critical surfaces (housekeeping surfaces) such as bedside tables contact intact skin and require low-level disinfection.
Question 5: An ICP observes that EVS staff are using the same mop head throughout an entire unit without replacement. The PRIMARY concern is:
- Increased cost of mopping supplies
- Cross-contamination of pathogens between patient rooms (Correct answer)
- Floors appearing less clean visually
- Mop head becoming too saturated to clean effectively
Correct answer: Cross-contamination of pathogens between patient rooms
Reusing mop heads without laundering between rooms can transfer pathogens room-to-room, increasing HAI risk.
Question 6: UV-C light devices used for terminal room disinfection are BEST described as:
- A replacement for manual cleaning with detergent
- An adjunct to, not a substitute for, manual cleaning (Correct answer)
- Effective only against bacterial spores
- Safe to use while patients are present in the room
Correct answer: An adjunct to, not a substitute for, manual cleaning
UV-C devices require prior manual cleaning to remove organic matter, as soil blocks UV penetration; they supplement but do not replace standard cleaning.
Question 7: What is the recommended dilution of sodium hypochlorite (bleach) for disinfection of surfaces contaminated with C. difficile spores?
- 1:100 dilution (approximately 500 ppm)
- 1:10 dilution (approximately 5,000 ppm) (Correct answer)
- 1:1,000 dilution (approximately 50 ppm)
- Undiluted bleach only
Correct answer: 1:10 dilution (approximately 5,000 ppm)
A 1:10 dilution of household bleach (~5,000 ppm available chlorine) is recommended by CDC for C. difficile spore decontamination.
CBIC Environmental Cleaning 2
Which EPA registration category must a disinfectant meet to be considered appropriate for use on a C. difficile-contaminated surface?