Antisepsis

Antisepsis is the practice of applying chemical agents to living tissue to inhibit or destroy pathogenic microorganisms and reduce the risk of infection. It underpins procedures in wound care, surgery, and routine hygiene by lowering microbial load on skin and mucous membranes. Antisepsis differs from disinfection, which targets inanimate surfaces, and from sterilization, which aims to eliminate all microorganisms including spores. Antiseptics are selected to balance antimicrobial activity with safety for host tissues.

Historical development began with Joseph Lister’s use of phenol (carbolic acid) in the 1860s, which dramatically reduced postoperative infections and popularized antisepsis. Since then, a wide array of agents has been developed for living tissue, including iodine-based preparations, chlorhexidine, alcohols, hydrogen peroxide, and phenolics. Modern antisepsis combines rapid action with residual activity while minimizing tissue irritation and systemic toxicity.

Common antiseptics include chlorhexidine (often in alcohol or aqueous solutions), povidone-iodine, ethanol or isopropanol, hydrogen peroxide, and certain phenolic compounds. Choice depends on context, tissue type, and infection risk. In preoperative skin preparation, chlorhexidine-alcohol is frequently used; povidone-iodine remains common for mucous membranes or wounds where chlorhexidine is unsuitable. Alcohols act quickly but can irritate, while chlorhexidine offers persistent activity but may be avoided on mucous membranes in some settings.

Antisepsis is applied in healthcare settings, in wound care, and in consumer products such as hand sanitizers. It is not a substitute for sterilization of instruments or devices. Proper concentration, contact time, and technique are essential. Safety concerns include skin irritation, allergic reactions, and cytotoxic effects on healing tissue. Guidelines from health authorities such as the World Health Organization and the CDC inform antiseptic selection and use.