Home Cosmetic Science Talk Formulating Safety of 0.5-1% LABSA in shampoo for pH adjustment

  • Safety of 0.5-1% LABSA in shampoo for pH adjustment

    Posted by Abdullah on December 15, 2021 at 3:04 pm

    I am making Shampoo with SLS/SLES/CAPB/APG with 14.4% total active surfactant. And adjust pH with citric acid to 4.1. as recently the price of citric acid has increased by 3x, my question is, is it safe to adjust the pH of shampoo with 0.5-1% LABSA instead of citric acid? 

    Abdullah replied 2 years, 6 months ago 5 Members · 9 Replies
  • 9 Replies
  • Mayday

    Member
    December 15, 2021 at 5:46 pm

    To hop on this question, is it unsafe to adjust pH using strong acids like HCl? I’ve seen that NaOH (strong base) can be used to adjust pH up for ingredients like Carbomer.

    Is there a difference in potential for skin irritation at the same pH?

    Are there any general principles to know if an acid or base can be safely used in cosmetics (aside from checking to see if it’s been used successfully by reputable manufacturers)?

    CosmeticIngredientReview doesn’t return a search result for Linear Alkyl Benzene Sulphonic Acid, any alkylbenzene, or hydrochloric acid (in my case): https://online.personalcarecouncil.org/jsp/IngredInfoSearchResultPage.jsp

  • DAS

    Member
    December 16, 2021 at 6:20 am

    It’s safe, although you already have high asm. I wouldn’t want that near my eyes. 
    @Mayday yes, it’s safe. In fact major brands use HCl and NaOH to adjust pH.
    https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=182.1057

    https://incidecoder.com/ingredients/hydrochloric-acid

    Sometimes Cosing db is handy: https://ec.europa.eu/growth/tools-databases/cosing/index.cfm?fuseaction=search.simple

  • Abdullah

    Member
    December 16, 2021 at 9:06 am

    DAS said:

    It’s safe, although you already have high asm. I wouldn’t want that near my eyes. 
    @Mayday yes, it’s safe. In fact major brands use HCl and NaOH to adjust pH.
    https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=182.1057

    https://incidecoder.com/ingredients/hydrochloric-acid

    Sometimes Cosing db is handy: https://ec.europa.eu/growth/tools-databases/cosing/index.cfm?fuseaction=search.simple

    Thanks 

    Of course i will reduce that amount of anionic surfactant.

  • ketchito

    Member
    December 16, 2021 at 1:39 pm

    DAS said:

    It’s safe, although you already have high asm. I wouldn’t want that near my eyes. 
    @Mayday yes, it’s safe. In fact major brands use HCl and NaOH to adjust pH.
    https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=182.1057

    https://incidecoder.com/ingredients/hydrochloric-acid

    Sometimes Cosing db is handy: https://ec.europa.eu/growth/tools-databases/cosing/index.cfm?fuseaction=search.simple

    As @Mayday and @DAS mentioned, you could use a solution of HCl for cost saving. Now, consider that the lower you go with your pH, the less detergency you’ll have from your anionic surfactants (I don’t see a practical need for going so low in pH).  

  • Abdullah

    Member
    December 17, 2021 at 1:58 am

    @ketchito no need but i go low pH because of better conditioning, being more gentle, needing less preservative. 

    Every surfactant SLS/SLES/CAPB/APG is at it’s full strength at pH 4. So why would they have less detergency? 

  • ketchito

    Member
    December 20, 2021 at 2:57 pm

    Anionoc surfactants have binding sites not only for metal ions but also for hydrogen protons, so the lower the pH, the more chances the oxygens in your anionics might be interacting with hydrogen ions, modifying the surface activity of those molecules. Not that your anionics won’t work at lower pH, but they’ll have less strenght. Also, SLES hydrolyzes at low pH (at lower than 4, the process is more rapid).

  • Abdullah

    Member
    December 20, 2021 at 3:50 pm

    ketchito said:

    Anionoc surfactants have binding sites not only for metal ions but also for hydrogen protons, so the lower the pH, the more chances the oxygens in your anionics might be interacting with hydrogen ions, modifying the surface activity of those molecules. Not that your anionics won’t work at lower pH, but they’ll have less strenght. Also, SLES hydrolyzes at low pH (at lower than 4, the process is more rapid).

    The system is not strongly buffered at pH 4.1. it has only 0.25% citric acid.
    When applied to hair it will be diluted with more than 10 times the amount of water in hair so the pH would be above 5 when it is cleaning the hair so it will be ok. 

    That is what i think. 

  • Quimico

    Member
    January 5, 2022 at 4:17 pm

    If you formulated properly the final product ph will be 5-6 no need for adjustment
    Use
    Water 
    EDTA
    GLYCEROL 
    SLES
    CC DEA
    CA BETAINE
    SALT AND ADDITIVES 

  • Abdullah

    Member
    January 6, 2022 at 3:27 am

    Quimico said:

    If you formulated properly the final product ph will be 5-6 no need for adjustment
    Use
    Water 
    EDTA
    GLYCEROL 
    SLES
    CC DEA
    CA BETAINE
    SALT AND ADDITIVES 

    I want it to be below 5

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