Home Cosmetic Science Talk Formulating One and done preservative….Does it exist?

  • One and done preservative….Does it exist?

    Posted by Graillotion on December 2, 2022 at 3:00 am

    I was reading an old thread today, and respected member said….There are no complete single ingredient preservatives that work on the full spectrum of potential pestilences that plague cosmetics.

    As I do not use parabens and F releasers, this thought had never crossed my mind, as I am required to create an elaborate web of preservation.  I just assumed the guys that used a potent F releaser along the lines of DMDM hydantoin could do a one and done, without having to worry about @PhilGeis reminding them the product had a weakness in the area of ___________.

    Now maybe I took the comment out of context, as the person that made the comment formulates a lot like I do, and he was referring to the realm we work in…. No ‘one and done’ preservative, to which I would certainly agree.

    So, the question is…. in the world of cosmetics….and one is open to any commonly acceptable preservatives….is there a one and done?  I realize everything is formula specific…and all that jazz.  But is there a single ingredient preservative…that might work for a number of typical moisturizing emulsions?  Let’s work under the basic framework of a well chosen pH, and a chelate….and maybe even a couple multi-functional potentiators.

    I often ask questions I will never incorporate into my own formulas, but as I try to help others, a vast array of knowledge is required.


    PhilGeis replied 1 year, 4 months ago 6 Members · 7 Replies
  • 7 Replies
  • Abdullah

    December 2, 2022 at 12:49 pm

    I don’t know about one single preservative but one blend may be phenoxyethanol+ ipbc for emulsions. 

    It might be one of the most effective, easy to work with, most gentle and least expensive preservative blends. 

  • PhilGeis

    December 3, 2022 at 1:59 pm

    Combinations - both have some activity to all bugs -  one of ’em has the best to the specific target group - in Abdullah’s example - phenoxyethanol for Gram negatives and IPBC for fungi.  Both have some activity to the other’s target group.  
    Combination not only “covers the waterfront” - in some cases offers increase efficacy - even true synergy (e.g. benzyl alcohol/benzoate/EDTA in shampoos) 
    The other concept is - it’s harder for a bug to adapt to resistance when there are two antagonists - even if one is weaker.  https://academic.oup.com/jpp/article-abstract/23/Supplement_1/136S/6200536

  • Pharma

    December 3, 2022 at 5:05 pm

    @Graillotion If you had asked that Q 30 years ago, I’d probably mentioned thiomersal. Many countries have, fortunately and for several reasons, discontinued/banned the use of mercury and organomercury compounds in general or at least for most applications at the end of last century/millenium.

    Several other compounds (mostly heavy metals) show a similar broad-toxicity antimicrobial effect (often alongside toxicity towards all other forms of life, too) and most have as well been discontinued or banned (for this and other reasons). The list includes antimony, arsenic, bismuth (fairly safe but quite weak, only bacteriostatic, and hence still in use for example in the US as Pepto-Bismol), lead, nickel, thallium, tin… heavy metals still in use are for example copper, silver, and zinc. Some organoborons also belong to this list of compounds showing an ‘oligodynamic effect’. Alas, the ones in use are less effective (assuming one uses safe levels) and often come with diverse drawbacks (and they don’t cover the whole microbial spectrum either).
    Other broad spectrum ‘toxins’ often won’t cover bacteria as well as yeast/fungi such as geneticin or glufosinate but will cover humans… a lose-lose situation :'( .
    Other options include chemically reactive ingredients such as strong oxidisers such as hydrogen peroxide and iodine… which nicely cover everything including spores and a good part of cosmetic ingredients and human skin as well. Another dead-end.
    Octenidine would cover a broad range of bacteria and yeasts (not clear how broad the effect is there). Efficacy against moulds is not known to me. All you had to do would be a combo with a broad-spectrum fungicide (if you sell outside of EU where either isn’t in the ‘approved preservatives annex’).
  • Graillotion

    December 3, 2022 at 8:20 pm

    Thank you all for your comments.  @PhilGeis comment about multiple layers of (even somewhat redundant) antagonist makes a lot of sense, and this is the format I currently have to follow with the less stellar performers.  Fortunately, with the aid of brilliant minds like @Pharma and @vitalys,  it is possible to create the set of hurdles that most bugs just look at …. and give up.  :D  

  • SandalwoodBreeze

    December 4, 2022 at 11:34 am

    Something that’s been discussed here a few times, using alcohol above about 20% should be effective. And an added benefit, it can make applying the product feel more refreshing. So far I only use it for my own projects and stick to the more usual “natural-adjacent” ingredients for commercial projects.

  • OldPerry

    December 6, 2022 at 2:41 am

    @CedarWind108 - unfortunately putting that much alcohol in formulas starts to raise flammability/explosion issues in production. We made hairsprays in a place we called the boom boom room.

  • PhilGeis

    December 6, 2022 at 12:04 pm

    Yes - and inhalation hazard.

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