If soap is used to make you clean, why does it leave a scum?

Answer 1

Commercially made bar soaps are formulated to mitigate all of these disadvantages:

A wide variety of emollient materials, such as shea or cocoa butters, are substantive to the skin.
Poorly finished soaps contain alkali (NaOH) and react mildly basically with skin and fabric; commercial products are finished to neutrality or to a weak acid content to prevent this and be more compatible with the skin's slightly acidic pH.
Commercial products use chelating molecules (sequestrants), often EDTA derivatives to bind with any free Ca or Mg ions and prevent soap scum. These also help reduce fragrance loss, discolouration and rancidity.

Answer 2

Beacause the dirt comes off WITH the soap...leaving the scum.

Answer 3

Well, I just don't know. Zest is not supposed to leave a film behind. As I sit here, wooly house coat on and towel around my head - the computer is between the bathroom and bedroom - I was enroute to get dressed after my shower and was pulled into Answers, yet again, had I seen your question before my shower, I could have studied the situation while in there...dang, next time maybe!

Answer 4

Because it mixes with the dirt and dead skin cells from your body creating the nasty soap scum it leaves on your tub surfaces. Yuck.

Answer 5

Thank you so much for using the name of "I am NOT geroge Bush". We would have all thought it was really our president asking and answering our questions.



oh yeah, good question. No idea.

Answer 6

Reaction with your skin is different than the tiles

Answer 7

It is attracted to all dirt, not just people dirt.

Answer 8

It dosen't with me...but I guess it does with you..but hey like attracts like!!!!!!