Home Cosmetic Science Talk Formulating Alcohol based liquid sanitizer discoloration

  • Alcohol based liquid sanitizer discoloration

    Posted by bahey on June 15, 2020 at 5:26 am

    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 
    bahey replied 4 years, 1 month ago 9 Members · 21 Replies
  • 21 Replies
  • letsalcido

    Member
    June 15, 2020 at 8:33 am

    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%.

  • bahey

    Member
    June 16, 2020 at 10:12 am

    90 % isopropyl alcohol 9% ethanol ( total 99 % alcohol)

  • ZivBA

    Member
    June 16, 2020 at 12:12 pm

    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.

  • Unknown Member

    Deleted User
    June 16, 2020 at 2:41 pm

    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.

  • letsalcido

    Member
    June 16, 2020 at 7:08 pm

    @bahey ah my bad, I didn’t see the other 10% was ethanol.

  • bahey

    Member
    June 17, 2020 at 5:28 am

    @bahey ah my bad, I didn’t see the other 10% was ethanol.

    Ok , Thanks

  • bahey

    Member
    June 17, 2020 at 5:29 am

    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

  • bahey

    Member
    June 17, 2020 at 5:38 am

    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
  • LincsChemist

    Member
    June 17, 2020 at 7:50 am

    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

  • amitvedakar

    Member
    June 17, 2020 at 9:01 am
    same problem i am facing. color: Brilliant blue.
    I think blue color is not compatible.
  • bahey

    Member
    June 19, 2020 at 2:51 pm

    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

  • bahey

    Member
    June 19, 2020 at 2:52 pm

    same problem i am facing. color: Brilliant blue.
    I think blue color is not compatible.

    Strange 

  • Cafe33

    Member
    June 19, 2020 at 4:35 pm

    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. 

  • bahey

    Member
    June 22, 2020 at 10:09 am

    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

  • bahey

    Member
    June 30, 2020 at 4:31 pm

    Still trying to solve the problem

  • em88

    Member
    July 6, 2020 at 6:48 pm

    Use Methylene blue.

  • amitvedakar

    Member
    July 8, 2020 at 10:17 am

    I think IPA purity matter.

  • Cafe33

    Member
    July 8, 2020 at 6:35 pm

    You have not identified the exact blue color you are using. 

  • Dr Catherine Pratt

    Member
    July 8, 2020 at 8:13 pm

    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

    Member
    July 8, 2020 at 8:17 pm

    Also I prefer ethanol all the way!

  • bahey

    Member
    July 21, 2020 at 6:31 am

    I am wondering too ! The formula has a white strange sediments?

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