Disinfectants

Disinfectants and sanitizers are non-selective agents used topically. Their effects range from simply reducing the number of microorganisms to a level safe for public health, to completely destroying all microbes present on a treated surface. Disinfectants are antimicrobial substances typically used on inanimate surfaces. For maximum effectiveness, it is essential to use the correct concentration of the product for the intended purpose.

Ideally, disinfectants should have a broad spectrum of activity, strong germicidal power, a rapid onset of action, and long-lasting effects. These compounds must remain stable under various environmental conditions such as pH, temperature, and humidity, and retain their effectiveness in the presence of debris, necrotic tissue, soil, and other organic matter. High lipid solubility and good diffusion further enhance their activity. Disinfectants should not damage the surfaces they are applied to and should not have unpleasant odors, colors, or contaminating properties—or these should be minimal.

Classification of Disinfectants
1. Acids

Strong mineral acids: sulfuric acid, hydrochloric acid

Weak organic acids: acetic acid

2. Alkalis

Sodium and calcium hydroxide, limewater, slaked lime

3. Alcohols

Ethanol, isopropanol

4. Biguanides

Chlorhexidine

5. Oxidizing agents

Peroxides (hydrogen peroxide, peracetic acid, potassium permanganate)

Halogens and halogen-containing compounds:
– Iodine (tincture of iodine, povidone-iodine)
– Chlorine (sodium hypochlorite, calcium hypochlorite)

6. Metals

Mercury compounds (mercuric bichloride, merbromin, thimerosal, nitromersol)

Silver-containing compounds

7. Phenols and related compounds

Phenol, cresols, hexachlorophene, pine tar, chloroxylenols

8. Reducing agents

Formaldehyde, glutaraldehyde, formalin, sulfur dioxide

9. Surface-active agents

Anionic agents: soaps

Cationic agents: benzalkonium chloride, benzethonium chloride