Antiseptics

Antiseptics are chemical agents applied to living tissue to prevent infection by inhibiting microbial growth or killing pathogens. They are used on skin, mucous membranes, and wounds, and in consumer products to reduce microbial load. Unlike disinfectants, which target inanimate surfaces, antiseptics are formulated for topical use and are not reliably sterilants. They can still cause irritation or allergy in some individuals.

Common antiseptics include alcohols (ethanol, isopropanol), povidone-iodine, chlorhexidine, hydrogen peroxide, phenolic compounds, and quaternary ammonium compounds such as benzalkonium chloride. Agents may be bactericidal or bacteriostatic and vary in spectrum, covering bacteria, fungi, and some viruses. Effectiveness can be reduced by organic matter, and many agents are cytotoxic at higher concentrations, potentially delaying wound healing.

Uses encompass preoperative skin preparation, wound cleansing, hand hygiene, and antiseptic mouthwashes. Selection depends on context, pathogen risk, tissue tolerance, and exposure duration. Some antiseptics are preferred for wounds (chlorhexidine, povidone-iodine), while others are limited by toxicity. Safety considerations include avoiding ingestion and contact with eyes or deep tissues; some agents have pregnancy or allergy contraindications.

Antiseptics are distinct from antibiotics, which target pathogens inside the body, and from disinfectants, which aim to kill microorganisms on inanimate surfaces. In practice, antiseptics provide rapid microbial reduction at the site of application rather than ongoing systemic therapy.