Home Cosmetic Science Talk Formulating Advanced Questions How to stop crystals forming in hair salt spray formula

  • How to stop crystals forming in hair salt spray formula

    Posted by OB_Ben on November 14, 2023 at 10:00 am

    I am working on a salt spray formula of:

    Aqua - 54%

    Alcohol denat. - 28%

    Magnesium Sulphate - 5%

    Sodium chloride - 4%

    Other - qs

    I am noticing large crystals forming inside the formula up the dip tube for the spray lid. I’ve never seen this before, does anyone have any ideas as to what these crystals are? Salt or Magnesium Sulphate? And what I could add to prevent recrystallisation?

    OB_Ben replied 7 months, 3 weeks ago 2 Members · 2 Replies
  • 2 Replies
  • chemicalmatt

    November 17, 2023 at 3:01 pm

    @OB_Ben Those crystals must be sodium chloride since it has a lower saturation point in water than has magnesium sulfate heptahydrate. Neither solvate in ethanol well so reduce the NaCl and ethanol and keep this spray out of your eyes. Consider also adding a smidge of propylene glycol to this. Retards the flash point and keeps the plumbing free in that dipstick.

    • OB_Ben

      November 20, 2023 at 5:05 am

      Great advice, thank you very much, Matt!

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