Home Cosmetic Science Talk Formulating Advanced Questions Preservation attributes of the organic acids

  • Preservation attributes of the organic acids

    Posted by chemicalmatt on June 24, 2019 at 4:37 pm

    Without spending lots of time on the phone discussing the matter with manufacturers or searching online, I thought I’d pitch to the forum here. Of the several preservatives that are only effective (pH < 6) as dissociated organic acids, e.g. benzoate, sorbate, dehydroacetate, why would you use more then just one? Isn’t there a hierarchy of efficacy known? And if there is, say its benzoate ion, why use any other. I’ve noticed some manufacturers using two or more in their blends. Solubility is the only factor I can identify. Discuss. 

    ozgirl replied 4 years, 9 months ago 5 Members · 4 Replies
  • 4 Replies
  • oldperry

    Member
    June 24, 2019 at 5:22 pm

    I would think that the different acids have a different level of activity against various organisms.  Maybe there is some bacteria that can tolerate sorbic acid but gets wiped out by benzoic acid.  Just my guess.

  • markbroussard

    Member
    June 24, 2019 at 9:42 pm

    I suspect the same … the different acids may have different modes of action and one alone is insufficient to stop microbial growth … and/or one acid might function as a baceriocide and the other as a fungicide.

  • das

    Member
    June 24, 2019 at 10:06 pm

    Synergy could be another reason.

  • ozgirl

    Member
    June 24, 2019 at 10:26 pm
    It could also be due to keeping them below regulatory limits. If you use two actives both at or below regulatory limits you might get greater effectiveness.
    Using two actives at low levels might also reduce the likelihood of adverse reactions to the consumer compared to a single active at a higher level. 

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