• Formulating

  Acceptable Deodorant Stick pH

  Posted by micheleZ on June 26, 2019 at 7:08 pm

  Hi. I have a question on stick deodorant using the standard sodium hydroxide 10% solution, 18% water, 45% propanediol, 20% glycerin, 0.8% ethylhexylglycerin, and then a little essential oil or fragrance to 100%.  This formula gives a finished product with an alkaline pH of about 9.  I’ve seen this formula listed in several places with no notes to adjust the pH.  Is it acceptable for a deodorant to have this high of a pH?  And if not, do I use citric acid to adjust?  

  MarkBroussard replied 5 years, 11 months ago 3 Members · 4 Replies

  • deodorant-stick-ph-level
• 4 Replies

• 

  erindlea

  Member

  June 26, 2019 at 8:49 pm

  I use citric acid to adjust my deodorant’s pH to around 9. This is a perfectly suitable pH for my sodium stearate based stick. It’s stable, effective, and non-irritating.

• 

  MarkBroussard

  Professional Chemist / Formulator

  June 26, 2019 at 9:41 pm

  @micheleZ

  Have you perhaps left a key ingredient out of your list? … I don’t see a gellant.  I’m assuming you’re using Sodium Stearate?

• 

  micheleZ

  Member

  June 27, 2019 at 4:41 pm

  Thanks, @erindlea.  I was concerned with disruption of the acid mantle, leading to irritation or inflammation.  Good to know!  

  Hi @MarkBroussard.  Sodium stearate is the result of the lye solution and stearic acid.  So, yes, that’s what I put on the ingredients deck.  

• 

  MarkBroussard

  Professional Chemist / Formulator

  June 27, 2019 at 7:35 pm

  @micheleZ:

  Why not just use premade Sodium Stearate? … so much easier that using Stearic Acid + NaOH and it’s inexpensive.

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