Common Disinfectants

Question 1

Phenols

Answer 1

1. Family: phenol
2. Mechanism: disrupts cell membranes and denaturates protein
3. Rarely used (caustic)

Question 2

Quarternary ammonium compounds

Answer 2

1. Family: cationic detergent
2. Mechanism: disrupts cell membranes and denatures protein
3. Also used as antiseptics

Question 3

Chlorine

Answer 3

1. Family: chlorine
2. Mechanism: oxidation of sulfhydryl enzymes and amino acids
3. Most common: sodium hypochlorite (household bleach)

Question 4

Iodophors

Answer 4

1. Family: iodine
2. Mechanism: oxidation of sulfhydryl enzymes and amino acids
3. Most effective skin antiseptics, associated with hypersensitivity

Question 5

Ethanol and isopropyl alcohol (70-90%)

Answer 5

1. Family: alcohol
2. Mechanism: disrupts cell membrane and denatures proteins, poor activity in dried blood and saliva
3. Most widely used skin antiseptic, evaporates quickly, used on skin prior to venipuncture or immunizations, isopropyl alcohol can be used as waterless handwash

Question 6

Hydrogen peroxide

Answer 6

1. Family: peroxide
2. Mechanism: oxidation of sulfhydryl enzymes and amino acids
3. Only catalase-negative organisms

Question 7

Chlorhexidine gluconate

Answer 7

1. Family: bis-biguanide
2. Disrupts cell membranes (cationic properties)
3. Highly substantive, used as a handwash and mouthrinse

Question 8

Triclosan

Answer 8

1. Family: bus-phenol
2. Mechanism: disrupts cell membranes
3. Handwash, ingredient in some toothpastes