• Question: What makes soap kill bacteria?

    Asked by item371ear to Alex, Jack, Scott on 22 Nov 2019.
    • Photo: Scott Dwyer

      Scott Dwyer answered on 22 Nov 2019: last edited 22 Nov 2019 11:00 am

      Soaps often have a chemical in them that make them antibacterial.
      One is called triclosan, but there are many others.
      At high concentrations, triclosan acts as a biocide (killing the bacteria) by interacting with multiple cytoplasmic (liquid inside the cell) and membrane targets (the outer circle of the cell that keeps it intact). However, at the lower concentrations seen in commercial products, triclosan appears bacteriostatic (which stops their reproduction), and it targets bacteria primarily by inhibiting fatty acid synthesis.

    • Photo: Jack Saunders

      Jack Saunders answered on 22 Nov 2019:

      Interesting question! Not all soap kills bacteria, only the soaps with a special chemical in them that sticks to the bacteria and stops them multiplying. This is why soap should never be eaten as it could damage our insides by sticking to us!