Antiseptic soap, sometimes called antibacterial soap or anti-fungal soap, is regular soap in liquid or solid form that contains some kind of ingredient that reduces the chance of infection when applied to the skin. These products also have antimicrobial properties, meaning they kill or inhibit the growth of microbes like bacteria, virus, or fungi. Alcohol, triclosan, and tetrasodium EDTA are three antiseptics commonly used in soap, and they are all examples of antibacterial antiseptics, meaning they are proven to be effective against bacteria.
Other antiseptics have anti-viral properties, and some are anti-fungal and can be used to treat or prevent fungal infections like athlete's foot, ringworm, or vaginal yeast infections. Many antiseptics have a combination of these various properties. Some essential oils, such as tea tree oil, contain naturally occurring antiseptics called terpenes that have antibacterial, anti-fungal, and antiviral properties. These various kinds of antiseptic ingredients are also used in soap.
Regular soap also has antiseptic properties by itself. Pure soap is made using some kind of animal or vegetable fat that is treated with an alkaline solution, commonly lye. Soap cleans and disinfects by making oils dissolve in water, thereby removing dirt and debris as well as various microbes present on the skin. Several scientific studies have shown that hand-washing using regular soap and water while scrubbing the hands for 15 seconds removes as many bacteria and other microorganisms as antiseptic soap containing triclosan. These tests were done using commonly available soaps with relatively low levels of triclosan, so the results might not apply to products containing more triclosan or to soaps made with other antiseptic ingredients.
Some scientists and medical professionals are critical of the increasing use of antiseptic soap and the addition of antibacterial ingredients to so many cleaning products. They believe that this practice might lead to more strains of bacteria becoming resistant to antibacterial agents, eventually causing antibiotic medications to become less effective. This could make it more difficult to treat serious medical conditions caused by bacteria, like staph infections and pneumonia. For example, many microorganisms are already resistant to triclosan, meaning that even though it is a proven antibacterial agent, it may not be as effective as stated by some soap manufacturers because many strains of bacteria are immune to it.