• Question: what are the chemicals in soap, that kill bacteria?

    • Keywords:
      • Royal Society of Chemistry: Find out more about:
      Asked by IzzyClifton to Sarah, Sankar, Jo, Becky, Alan on 13 Mar 2015.
      • Photo: Jo Sadler

        Jo Sadler answered on 13 Mar 2015:

        Most antibacterial soaps contain at least one out of triclosan, triclocarban or chloroxylenol. These compounds stop growth of bacteria by inhibiting fatty acid synthesis. Some soaps also contain a compound known as EDTA which binds to metal ions which bacteria need to grow.

      • Photo: Becky Gregory

        Becky Gregory answered on 14 Mar 2015:

        Soap contains hydrophobic (water-repelling, so it hates water) fatty acids. These stick to other hydrophobic substances, such as the dirt that needs to be cleaned. Sodium hydroxide makes up the hydrophilic (water-binding, it loves water) part of the soap, and causes the fatty acids to become encapsulated in water droplets. The dirt, oil and bacteria can then easily be washed away within these caspules.
        Therefore, just regular soap and water will remove most bacteria and prevent infections. Antibacterial soaps will actually kill some bacteria though, using an antibacterial agent (often triclosan). However, it is believed that this agent can need up to two minutes before it can work, and most people are too impatient to wash their hands for this long.

      • Photo: Alan McCue

        Alan McCue answered on 16 Mar 2015:

        Nothing to add here

    Comments