• Off Topic

  MIC and pH……

  Posted by Graillotion on October 1, 2023 at 11:26 pm

  I have to assume….in the context of preservatives….especially those that interact heavily with pH….that when MIC numbers are given…this is given in the context of a set pH.

  What is the pH assumption…that MIC numbers are given? Since I am working with Mummy bloggers….you can see where I am headed…. at what pH are those crappy preservatives presenting MIC data? I guess I also mean…when I look at scientific data…and they display MIC numbers….what pH was the reference point?

  Thank You in advance.

  @PhilGeis

  PhilGeis replied 1 year, 2 months ago 2 Members · 7 Replies
• 7 Replies

• 

  PhilGeis

  Member

  October 2, 2023 at 5:29 am

  Pretty sure MIC protocols all use media at +/- neutral pH. MIC is pretty meaningless - inhibition in an overnight culture is a pretty low modest target when the standard is stable kill through 4 weeks.

  • 

    Graillotion

    Member

    October 2, 2023 at 2:01 pm

    @PhilGeis … so you are telling me….MIC numbers for organic acid based preservatives…are provided in an almost neutral environment….where they are essentially inactive?

  • 

    Graillotion

    Member

    October 2, 2023 at 2:03 pm

    If MIC numbers have so little value…. What readily available information can one use, to make a proper evaluation?

    Again….I am not using these products….just trying to help those that have drunk the Kool-Aide.

    • 

      PhilGeis

      Member

      October 2, 2023 at 2:31 pm

      It’s just inhibition (not kill) vs the wimpy lab strains and only for 12-24 hours..

      Efficacy in a formula - and experience wiith other formulas.

      • 

        Graillotion

        Member

        October 3, 2023 at 2:43 pm

        So, in the land of poor preservatives that saturate the market….is it safe to say….the only marketing leg they stand on….is the MIC numbers…which in a nutshell….have very little applicable value?

        Aloha

        @PhilGeis

        BTW…. for the PET test/s you consider superior to

    • 

      Graillotion

      Member

      October 3, 2023 at 2:47 pm

      Sorry…..some glitch cut me off……..

      …… Continued…….. For the PET test/s that you consider superior (more rigorous) than USP 51…. do they contain additional pathogens beyond the typical 5? A whole different slate….or a slate of the 5 plus some bonus contenders? I guess what I am asking…..what makes it more rigorous?

      • 

        PhilGeis

        Member

        October 3, 2023 at 3:17 pm

        MIC - it’s pretty meaningless.

        For challemge - USP/EP/BP/ISO/ASTM all have the same bugs (these were 1st isolated 60 + years ago - the staph almost a century old) and are more of less identical but for acceptance criteria. ISO is ok but it offers the wriggle room of A amd B, and non of these demands the bugs actually be eliminated at any time point. In real life with real contaminants - bugs that hang around learn to grow.

        .Major companies that use this general challenge protocol demand even more - usually no detects at 7 days. They typically also add bugs that can or have contaminate esp, Burkholderia cepacia and a few others.

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