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

1:100 dilution (500 ppm)

Answer

Undiluted (50,000 ppm)

Answer

1:1,000 dilution (50 ppm)

Question 2

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

Accepted Answer

It is less irritating to eyes and nasal passages

Answer

It requires no contact time for sterilization

Answer

It is effective only against bacteria

Answer

It does not require personal protective equipment

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

Non-enveloped viruses

Answer

Bacterial spores

Answer

Prions

Question 4

Which statement correctly distinguishes a disinfectant from a sterilant?

Accepted Answer

Sterilants destroy all microbial life including spores; disinfectants do not

Answer

Disinfectants eliminate all forms of microbial life; sterilants do not

Answer

Sterilants are only used on living tissue; disinfectants are used on surfaces

Answer

There is no practical difference between a disinfectant and a sterilant

Question 5

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

Accepted Answer

Tuberculocidal

Answer

Fungicidal

Answer

Virucidal

Answer

Sporicidal

Question 6

What is the primary purpose of pre-cleaning instruments and surfaces before applying a disinfectant?

Accepted Answer

To remove organic matter that inactivates disinfectants

Answer

To activate the disinfectant's chemical properties

Answer

To warm up the surface for better absorption

Answer

To satisfy OSHA documentation requirements

Question 7

Phenolic compounds used as disinfectants in dental settings are classified at which level?

Accepted Answer

Intermediate-level

Answer

Low-level only

Answer

High-level

Answer

Chemical sterilant