An antiseptic is a chemical that destroys or stops the growth of many microorganisms (particularly bacteria and fungi). Antiseptics are weak germicides that can be used on the skin; they are used to avoid sepsis from contamination of body surfaces and surgical instruments. Some antiseptics are used as disinfectants to make places or objects germ-free.


Vinegar and cedar oil have been used from earliest times to treat wounds and for embalming. Modern antisepsis was pioneered by Semmelweis, Joseph Lister, and Robert Koch, and dramatically reduced deaths from childbirth and surgery in the second half of the 19th century.


Commonly used antiseptics and disinfectants include iodine, chlorine, hypochlorous acid, ethanol, isopropanol (see alcohol), phenols (including hexachlorophene), quaternary ammonium salts (see ammonia, methanal (formaldehyde), hydrogen peroxide, potassium permanganate (see potassium, and acriflavine (in acridine dye).


Heat, ultraviolet, and ionizing radiation also have antiseptic effects.


See also antibiotic.