Disinfection and Sterilizing Agents

Question 1

First Aid Disinfectants

Define disinfection.

Answer 1

Reduction of organism counts to safe levels

Question 2

First Aid Disinfectants

Define sterilization (in terms of cleaning).

Answer 2

Inactivation of all microbes (including spores)

Question 3

First Aid Disinfectants

Autoclaves use pressurized steam at > _____°C.

They ______ (do / do not / may not reliably) inactivate spores.

They ______ (do / do not / may not reliably) inactivate prions.

Answer 3

Autoclaves use pressurized steam at > 120 °C.

They do inactivate spores.

They may not reliably inactivate prions.

Question 4

First Aid Disinfectants

How does alcohol work as a disinfectant?

Is it sporicidal?

Answer 4

Protein denaturation, cell membrane disruption

no

Question 5

First Aid Disinfectants

How does chlorhexidine work as a disinfectant?

Is it sporicidal?

Answer 5

Protein denaturation, cell membrane disruption

no

Question 6

First Aid Disinfectants

How does chlorine work as a disinfectant?

Is it sporicidal?

Answer 6

Protein oxidization and denaturation

yes

Question 7

First Aid Disinfectants

How does ethylene oxide work as a disinfectant?

Is it sporicidal?

Answer 7

Alkalation

yes

Question 8

First Aid Disinfectants

How does hydrogen peroxide work as a disinfectant?

Is it sporicidal?

Answer 8

Free radical oxidation

yes

Question 9

First Aid Disinfectants

How do iodine and iodophors work as disinfectants?

Are they sporicidal?

Answer 9

Halogenation of DNA, RNA, and proteins

may be

Question 10

First Aid Disinfectants

How do quarternary amines work as disinfectants?

Are they sporicidal?

Answer 10

Impair cell membrane permeability

no

Question 11

First Aid Disinfectants

Identify a few sporicidal disinfectants.

Answer 11

Chlorine

Ethylene oxide

Hydrogen peroxide

(maybe iodine and iodophors)