TDS Control in the Production Water for Cosmetics

Hi, all.

I know that the % of total dissolved solids is significant in emulsion stability, but I have not found any guidelines on this. Any one with ideas?

Comments

  • PerryPerry Administrator, Professional Chemist
    What is your specific question?
  • PharmaPharma Member, Pharmacist
    Use distilled or demineralised water ;) .
  • Perry said:
    What is your specific question?
    My Question is: just like we have pH control for preservatives and anionic/cationic surfactants, do we have the same for TDS?
  • Pharma said:
    Use distilled or demineralised water ;) .
    I should, but it is rather expensive. I was finding a way of lowering the cost by using tap water.
  • The time you spend trying to work out a way to use tap water and repairing failed emulsions may end up being more expensive than just buying  good starting material. Do you have any water quality reports that let you know the typical 'contaminants' of your tap water? Does it vary throughout the year?
  • PharmaPharma Member, Pharmacist
    Abbass_1 said:
    My Question is: just like we have pH control for preservatives and anionic/cationic surfactants, do we have the same for TDS?
    I still don't really get it. TDS is everything dissolved in water which doesn't evaporate upon boiling. IMHO TDS can't be compared to pH.
    Where I live, water quality reports of our tap water are available online ;) .
    Anyway, you can control some side-effects resulting from certain dissolved salts such as heavy metals (most of all iron) by adding a chelate.
    The effect of divalent cations (usually calcium) on emulsion stability can not be quenched/prevented by suitable means.
    Buy a small RO unit or at least a cation exchange resin cartridge as used to produce soft water by exchanging calcium/magnesium against sodium.
    Demineralised water (the one for car coolers or pressing irons) isn't that expensive.
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