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Do these two cancel each other out?

  1. Apr 20, 2017 #1
    I'm wondering if by mixing these to handwashes, the antibacterial effect of both is cancelled.

    Handwash 1: Aqua, Sodium Laureth Sulfate, cocamidopropyl betaine, sodium chloride, glycerin, polyquaternium-7, parfum, sodium benzoate, lactic acid, tetrasodium glutamate diacetate, benzotriazolyl dodecyl p-cresol, limonene, hexyl cinnamal, butylphenyl methylpropional, linalool, CI 42051

    Handwash 2: Aqua, sodium laureth sulfate, sodium chloride, citric acid, cocamidopropyl betaine, sodium benzoate, cocamide DEA, disodium EDTA, glycerin, PEG-7 glyceryl cocoate, chamomilla recutita flower extract, methylchloroisothiazolinone, methylisothiazolinone, potassium sorbate

    Any idea?

  2. jcsd
  3. Apr 20, 2017 #2
    In both cases, the main antibacterial is sodium benzoate. They won't interfere with each other.
    The second handwash has methylchloroisothiazolinone, methylisothiazolinone, and potassium sorbate. It is unlikely that anything in the first handwash would interfere with these, but I don't know.

    Here's the ingredients for the first one:

    Aqua: water
    Sodium Laureth Sulfate: a soap and surfactant
    cocamidopropyl betaine: a natural mix, a surfactant
    Sodium Chloride: salt
    glycerin: probably included to provide a sweet scent
    polyquaternium-7: antistatic or "fabric softener"
    parfum: fragrance
    sodium benzoate: preservative, this is your first antibacterial agent, it requires an acid environment to be effective
    lactic acid: and here's you acid environment
    tetrasodium glutamate diacetate: preservative booster (antibacterial)
    benzotriazolyl dodecyl p-cresol: protects this mixture from UV
    limonene: orange scent
    hexyl cinnamal: fragrance
    butylphenyl methylpropional, fragrance
    linalool, fragrance
    CI 42051: blue coloring

    Additional ingredients in second one:
    citric acid: provides acid environment and perhaps fragrance
    cocamide DEA: foaming agent
    disodium EDTA: water softener
    PEG-7 glyceryl cocoate: skin conditioner
    chamomilla recutita flower extract: fragrance
    methylchloroisothiazolinone: antibacterial
    methylisothiazolinone: antibacterial
    potassium sorbate: antibacterial
  4. Apr 20, 2017 #3
    Wow - thank you so much for that detailed reply! I'm pleased that you've explained what the different ingredients do - always wanted to know that!

    So, it looks like handwash 1 wouldn't be weakened by handwash 2, but it's possible that handwash 2 is weakened by handwash 1. Have I got that right?
  5. Apr 20, 2017 #4
    It is very unlikely that either will interfere with the other. But if you are looking for an antimicrobial handwash, stick with handwash 2; it was specifically developed for that. Mixing it with handwash 1 won't make it more antimicrobial.
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