Alcohol based liquid sanitizer discoloration

After production of 70 % isopropyl sanitizer liquid ( blue color ) it turned to colorless liquid . 
Any recommendations?

70 % alcohol of ( 90% isopropyl alcohol 10% ethyl alcohol) ,
monoprobelen glycol , blue colour , water is the other ingredients.
also i had found a white or colorless residuals ( sedimentation ) in the bottles  of discolored batch . 

After adding color to each bottle to test it turned to colorless again !!! 

Thanks for helping 

Comments

  • Obviously whatever you are using to color this product is not compatible with alcohol. What is the exact ingredient? Also, you can get rid of it, sanitizers don’t need color.

    Lastly, your sanitizer is not 70% alcohol, it’s 63%. You need 77.8% v/v of 90% v/v IPA in your formula for a final concentration of 70%.


  • baheybahey Member
    90 % isopropyl alcohol 9% ethanol ( total 99 % alcohol)
  • ZivBAZivBA Member

    Try using Benzophenone 4- 0.05% for color protection.

    Check the final pH of your product, most pigments are pH sensitive.

    I've put the Blue NO 1 in pH=9.50, it turned Purple after 12 hours.

    Chief Chemist/ R&D Manager at SASA Cosmetics
  • To add to ZivBA's comment, make sure you test the pH of your blue solution in water and make any pH adjustments before adding to the alcohol - alcohols at such a high percentage will not give you an accurate pH reading.
  • @bahey ah my bad, I didn’t see the other 10% was ethanol.
  • baheybahey Member
    @bahey ah my bad, I didn’t see the other 10% was ethanol.
    Ok , Thanks
  • baheybahey Member
    To add to ZivBA's comment, make sure you test the pH of your blue solution in water and make any pH adjustments before adding to the alcohol - alcohols at such a high percentage will not give you an accurate pH reading.
    To add to ZivBA's comment, make sure you test the pH of your blue solution in water and make any pH adjustments before adding to the alcohol - alcohols at such a high percentage will not give you an accurate pH reading.
    I will check colour dye PH
  • baheybahey Member
    ZivBA said:

    Try using Benzophenone 4- 0.05% for color protection.

    Check the final pH of your product, most pigments are pH sensitive.

    I've put the Blue NO 1 in pH=9.50, it turned Purple after 12 hours.

    I am thinking what will cause very high or very low ph value ? 
    It’s alcohol and water almost no other ingredients .
    it’s not a color change it’s discoloration .
    i only change the source of alcohol, the other batches didn’t change the color
  • It's possible if you've only seen this happen with a new batch of alcohol that they've added a denaturant that is in some way incompatible with your colouring
  • same problem i am facing. color: Brilliant blue.
    I think blue color is not compatible.
  • baheybahey Member
    It's possible if you've only seen this happen with a new batch of alcohol that they've added a denaturant that is in some way incompatible with your colouring
    Yes ,may be
  • baheybahey Member
    same problem i am facing. color: Brilliant blue.
    I think blue color is not compatible.
    Strange 
  • Cafe33Cafe33 Member
    I have used a green color mix for my Apple scented alcohol sanitizer and it contains Blue no 1. There has been no color change whatsoever. 

    I am using 70% EtOH (Drinking quality, not denatured). The batch is from March and no issues whatsoever. 
  • baheybahey Member
    What’s the probabilities of this discoloring,
    first time to be happened, i use the same color from a while ,
    the only new factor is the source of Alcohol.it is isopropyl alcohol by the way
  • baheybahey Member
    Still trying to solve the problem
  • em88em88 Member
    Use Methylene blue.


  • I think IPA purity matter.
  • Cafe33Cafe33 Member
    You have not identified the exact blue color you are using. 
  • As said what are the specifications of the blue? & your pH! WHO also states no colour but that’s up to you. Good luck!
    Dr. Catherine Pratt
    (B.Sc with HONS I , Ph.D Analytical/Organic Chem and Microbiology), Cosmetic Chemistry IPCS)
  • Also I prefer ethanol all the way!
    Dr. Catherine Pratt
    (B.Sc with HONS I , Ph.D Analytical/Organic Chem and Microbiology), Cosmetic Chemistry IPCS)
  • baheybahey Member
    I am wondering too ! The formula has a white strange sediments?
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