^{Disinfectants44,45}

Alcohols (Ethanol)

• Mechanism of action Denature proteins, precipitate nucleic acids

• Spectrum Bacteria, Mycobacteria, Fungi, Viruses (all), Spores

• Advantages Broad spectrum

• Disadvantages Carcinogenic and irritant to mucus membranes and tissues

 

Aldehydes (Formaldehyde, Glutaraldehyde)

• Mechanism of action Precipitate proteins, denature lipids

• Spectrum Bacteria, Mycobacteria, Fungi, Enveloped viruses

• Advantages Fast acting, low cost

• Disadvantages Rapid evaporation, need sufficient contact time, flammable

 

Biguanides (Chlorhexidine, Polyhexamethylene bigaunide)

Widely used as antiseptics.⁸⁵

• Mechanism of action Alter membrane permeability

• Spectrum Bacteria

• Advantages Non-toxic on skin and mucus membranes

• Disadvantages Only function in limited pH range (5-7), narrower spectrum

 

Sodium Hypochlorite (Bleach)

• Mechanism of action Denatures proteins

• Spectrum Bacteria, (Mycobacteria), (Fungi), Viruses (all), (Spores)

• Advantages Broad spectrum, low cost

• Disadvantages Irritant to tissues, never mix with acids as toxic gas is produced

 

Iodophors (Povidone-Iodine)

May be antiseptic or disinfectant depending on concentration⁸⁵

• Mechanism of action Denature proteins

• Spectrum Bacteria, Mycobacteria, Fungi, Viruses (all), Spores

• Advantages Low toxicity, long shelf life

• Disadvantages Stain materials and surfaces, inactivated by quaternary ammonium compounds (QACs)

 

Hydrogen Peroxide

• Mechanism of action Denatures proteins and lipids

• Spectrum Bacteria, Mycobacteria, Fungi, Viruses (all)

• Advantages Broad spectrum

• Disadvantages Toxic gases when in contact with chlorine, damages some metals

 

Phenols(Triclosan)

• Mechanism of action Denature proteins, bind phospholipids

• Spectrum Bacteria, Mycobacteria, (Fungi), (Enveloped viruses)

• Advantages Fairly good activity with organic material, non-corrosive

• Disadvantages Skin and eye irritation, toxic especially to cats

 

Quaternary ammonium compounds (QACs)

• Mechanism of action Precipitate proteins, denature lipids

• Spectrum Bacteria (Gram-positive), (Enveloped viruses)

• Advantages Non-irritating to skin, effective at high temperatures and high pH

• Disadvantages Narrower spectrum