A few questions about a simple mist

DaveStoneDaveStone Member
edited August 2021 in Formulating
Say you wanted to make a 8oz solution consisting of 93-94% distilled water, 3% 1,3-propanediol, 3% sodium lactate (powder)

1) Would Germall Plus (powder) be an adequate preservative here, or would another work better (I read it might not work in sprayers)?  If so, do you always use the minimal recommended percentage?

2) Do you have to heat and hold?

Also, seeing as the humectants add up to 6%...is that a good amount...what's the max recommended amount (before the solution would become irritating, if possible)?



Comments

  • You can't really tell if the preservative would be sufficient unless you conduct PET (preservative efficacy testing). I've never worked with Germall Plus, but did work with Liquid Germall Plus. At 0.5% [Maximum input] I've never experienced any growth (at least eye visible - mold, spots, etc ... ). If they say Germall plus does not work well in sprayers, I would not go for it. 

    If you are home maker, always go for the maximum recommended input. 

    Germall Plus is heat sensitive (50°C), do not heat and hold.. If you use clean distilled water, clean equipment etc, you should be fine for cold processing. 

    Humectants input - depends. You need to check supplier's recommended input.
    Glycerin - 1- 10% (over 5% will feel sticky/tacky). 
    Sodium PCA - 2-5% (more expensive, but high performance, works good with Sodium Hyaluronate)
    Propylene Glycol - 1 - 10% (up to 20%?)
    Propanediol - 1 -10% (not tacky, I like this one)

    and so on. :) Hope that helps.


  • Liquid Germall Plus is easier to use in my opinion, tiny amounts of powder are hard to measure and work with.
  • DaveStoneDaveStone Member
    edited August 2021
    Paprik said:
    You can't really tell if the preservative would be sufficient unless you conduct PET (preservative efficacy testing). I've never worked with Germall Plus, but did work with Liquid Germall Plus. At 0.5% [Maximum input] I've never experienced any growth (at least eye visible - mold, spots, etc ... ). If they say Germall plus does not work well in sprayers, I would not go for it. 

    If you are home maker, always go for the maximum recommended input. 

    Germall Plus is heat sensitive (50°C), do not heat and hold.. If you use clean distilled water, clean equipment etc, you should be fine for cold processing. 

    Humectants input - depends. You need to check supplier's recommended input.
    Glycerin - 1- 10% (over 5% will feel sticky/tacky). 
    Sodium PCA - 2-5% (more expensive, but high performance, works good with Sodium Hyaluronate)
    Propylene Glycol - 1 - 10% (up to 20%?)
    Propanediol - 1 -10% (not tacky, I like this one)

    and so on. :) Hope that helps.



    By adequate preservative, I meant would it (Germall Plus) be compatible in that formula. I read that certain preservatives are incompatible with certain ingredients.
    WRT to the humectants, I was more so wondering what the total recommended percentage is? My example would amount to a 6% humectant solution. I wanted to know if that's too little, and what would be too high. Say I used 10% propandiol, 3% glycerin, and 3% sodium lactate...which makes the overall amount 16% humectants. Is that okay?


  • Would Biguanide 20 and citric acid work?
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