DANB DANB Chemical Disinfectants & Sterilants 2

Question 1

What is the recommended concentration of sodium hypochlorite (bleach) for disinfection of clinical contact surfaces in dental settings?

Accepted Answer

1:10 dilution (1,000–5,000 ppm)

Answer

A 1:10 dilution of household bleach (approximately 1,000–5,000 ppm available chlorine) is recommended for disinfecting dental clinical contact surfaces.

Question 2

Ortho-phthalaldehyde (OPA) is considered advantageous over glutaraldehyde primarily because:

Accepted Answer

It is less irritating to eyes and nasal passages

Answer

OPA produces less vapor and is less irritating to mucous membranes than glutaraldehyde, making it safer for clinical use while still providing high-level disinfection.

Question 3

Alcohol-based disinfectants (e.g., 70% isopropyl alcohol) are most effective against which category of microorganisms?

Accepted Answer

Lipid-enveloped viruses and vegetative bacteria

Answer

Alcohols are effective against lipid-enveloped viruses (e.g., HIV, HBV) and vegetative bacteria but are not sporicidal and have limited activity against non-enveloped viruses.

Question 4

Which statement correctly distinguishes a disinfectant from a sterilant?

Accepted Answer

Sterilants destroy all microbial life including spores; disinfectants do not

Answer

Sterilants destroy all forms of microbial life including highly resistant bacterial spores, while disinfectants reduce microbial load but may not eliminate spores.

Question 5

EPA-registered hospital disinfectants used on clinical contact surfaces in dental offices must carry which specific label claim?

Accepted Answer

Tuberculocidal

Answer

CDC guidelines specify that EPA-registered hospital disinfectants with a tuberculocidal claim are appropriate for clinical contact surfaces because M. tuberculosis serves as a benchmark for intermediate-level disinfection.

DANB Infection Control Exam Practice Test

DANB Infection Control Exam Practice Test

DANB DANB Chemical Disinfectants & Sterilants 2