Home Cosmetic Science Talk Formulating “Best” “Natural” “Broad-category” Preservative

  • “Best” “Natural” “Broad-category” Preservative

    Posted by RDchemist15 on July 11, 2022 at 5:46 pm

    Hello everyone,

    I have a feeling this will be a very contentious post (hence all those quotation marks) so hopefully I can get some great help.

    What I am looking for is the best single option preservative for as many water-based cosmetic categories as possible. Basically if you can only hold 1 preservative raw material (or combination) what would it be?

    So what is “best”? Best is a single preservative or combination that is highly effective against all microbial contamination. Best can then be further ranked by applying to as many water-based cosmetic categories as possible, the requirement of only carrying a single raw material item, and cost in that order. 

    So what is “natural”? Natural here is not defined by any regulation listing (though in a tie- could be the tie breaker). Natural here is not: parabens, formaldehyde releasers, MIT/CMIT, phenoxyethanol, or iodopropynyl butylcarbamate.

    So what is “broad-category”? Broad category here is water-based cosmetics. Body washes, shampoos, conditioners, lotions, toners, scrubs, gels, sprays, etc. If it fits in this category the preservative should not cause drastic colour changes, drastic changes in viscosity, drastic changes in smells, be stable over a wide range of temperatures, etc.

    I am trying to reduce dozens of preservatives down to hopefully 1 (that would be always on hand, and could be reached for first) as I am less experienced in this area of “natural”. 

    Final notes:
    1) Yes, I know you’re answers can depend on “well it depends on the product”. This is not replacing any required microbial testing for products as well as regular stability testing.
    2) Yes, any answer will be combined with glycols and a chelator at the appropriate pH.

    As it matters so much for products in this category, I will also ask for the most common scenarios of pH: 1) ph between 4.0 - 5.0 and 2) pH >6.0

    Thanks, 
    RDChemist15

    bcakesllc replied 7 months, 3 weeks ago 7 Members · 19 Replies
  • 19 Replies
  • pharma

    Member
    July 11, 2022 at 6:06 pm
    None, there is none… unless you’re willing to add >20% ethanol to your products.
    You could probably make a blend of different single ones so you end up with one single bottle containing ‘one’ preservative?
    The best technique, especially in ‘natural’ (or alternative) formulations is a hurdle approach, which means many hurdles and not just one. The more ‘natural’ you go, the less broad spectrum the preservatives and ‘preservative alternatives’ tend to become. Formaldehyde, mercury, borax and so on don’t distinguish what they kill, they just kill. ‘Modern’ (many of which aren’t even new) alternatives however…
  • RDchemist15

    Member
    July 11, 2022 at 6:21 pm

    Hi @Pharma, yes by single I don’t necessarily mean only 1 raw material INCI, I mean 1 raw material order. For example, I have pretty much the entire Euxyl and Lincoln lines. If I absolutely needed multiple product orders, then ideally it would be (mystery product) + (sodium benzoate or potassium sorbate), as we keep those more readily stocked.

  • markbroussard

    Member
    July 11, 2022 at 6:49 pm

    @RDchemist15

    Linatural Ultra-2 + Sodium Benzoate + Chelator + pH might be a good place to start for pH < 6.0

    • bcakesllc

      Member
      August 7, 2023 at 7:44 am

      Then would it be reasonable to blend Linatural Ultra-2 + Gluconolactone (and) Sodium Benzoate where Gluconolactone is the Chelator?

      • PhilGeis

        Member
        August 7, 2023 at 3:05 pm

        That’s a couple of weak organic acids with an ineffective organic acid and a weak unstable chelator. Even at a favorable pH </~ 5.5, that’s a poor system.

        • bcakesllc

          Member
          August 7, 2023 at 4:17 pm

          Thank you Phil.

  • RDchemist15

    Member
    July 11, 2022 at 7:02 pm

    @MarkBroussard Wow, just my luck I have Ultra-1 and Ultra-3. One more sample to order.

  • oldperry

    Member
    July 11, 2022 at 8:11 pm

    You didn’t really define “natural” only saying what it is not. 

    So what is “natural”? Natural here is not defined by any regulation listing (though in a tie- could be the tie breaker). Natural here is not: parabens, formaldehyde releasers, MIT/CMIT, phenoxyethanol, or iodopropynyl butylcarbamate.

  • PhilGeis

    Member
    July 11, 2022 at 11:53 pm

    There are many if you drop the pretense of protecting the user.  How will you qualify?

    Mark - please relate the efficacy data that would support that system

  • abdullah

    Member
    July 12, 2022 at 3:31 am

    Also there isn’t one preservative or blend that is good for both emulsions and shampoos except DMDM hydantoin. 
    There will be side effects like reduced viscosity, reduced activity, unnecessary high cost, irritation and so.

    I suggest you have two combinations. One for cleansing products. One for leave on products.

  • RDchemist15

    Member
    July 12, 2022 at 12:29 pm

    @Perry This isn’t for any specific product so I don’t really have a standard right now for what “natural” is. But all natural standards are in agreeance for what it is not, so that’s why that’s included. So for this purpose anything that doesn’t land in the not list can be this version of “natural”.

    @PhilGeis We won’t be doing that for obvious reasons, which is why I defined the importance of “best” as its highest criteria. We have a micro lab in house for all raw material and finished goods plate test counts as well as send a sample of finished good for 3rd party USP 51 challenge testing. If your opinion is that there is no preservative system that effectively fits all that criteria, that’s great, I’d like to hear that.

    @Abdullah I’m ok with all those side effects listed. I’ve worked with a lot of these blends and can account for them. And yes I am pretty much looking for a functional replacement for DMDM. Do you have a top suggestion for a cleansing preservative or a leave on preservative that fits?

  • abdullah

    Member
    July 12, 2022 at 1:25 pm

    My top suggestion would be Benzostat if you want to use only one preservative and not use those that you have listed. 

    It is
    71% benzyl alcohol

    15% caprylhydroxamic acid
    14% glycerin

  • oldperry

    Member
    July 12, 2022 at 1:42 pm

    Best is a single preservative or combination that is highly effective against all microbial contamination. and also is allowed by most natural standards

    - There is no single preservative or blend because nothing within your parameters is “highly effective against all microbial contamination.”

    If you’re not going to use formaldehyde, you’re pretty much SOL.

    According to your criteria, here are all the available COSMOS allowed ingredients claimed to be anti-microbial. Most of these are boosters or ineffective except in the specific systems tested by the supplier of those materials.  

    Benzoic acid
    Sodium Benzoate
    Benzyl alcohol
    Sorbic acid 
    Potassium Sorbate
    Phenethyl alcohol
    Dehydroacetic acid

    Sodium Dehydroacetate
    Salicylic acid
    Pentylene Glycol
    Polyglyceryl-3 Caprylate
    Gluconolactone
    Glyceryl Caprylate
    Glyceryl Laurate
    Sodium Levulinate
    Sodium Anisate
    Silver oxide
    Silver Citrate
    Colloidal Silver
    Lactic Acid
    Ethyl Lactate
    Zinc Lactate
    Sodium Usnate
    Polyepsilon-lysine
    Phenylpropanol
    Zinc Undecylenate
    Lactobacillus Ferment 
    Leuconostoc/Radish Root ferment
    Xylityl Sesquicaprylate
    Populus Tremuloides Bark Extract
    Ribes Nigrum (Black Currant) Fruit Extract
    Sambucus Nigra Fruit Extract
    Magnolia Officinalis Bark Extract
    Humulus Lupulus (Hops) Extract
    Bitter orange extract
    Pistacia Lentiscus
    Vitis Vinifera Seed Extract
    Ganoderma Lucidum Extract
  • RDchemist15

    Member
    July 12, 2022 at 2:12 pm

    @Abdullah Thanks! Good to know that’s the second recommendation with a Benzyl Alcohol backbone

  • abdullah

    Member
    July 12, 2022 at 2:32 pm

    Be aware that benzyl alcohol is not more natural than phenoxyethanol or Paraben. 

    Also it is ranked lower in all these aspects compared to those preservatives that you don’t want to use.
    preservation effectiveness, stability of preservative it self, emulsion stability, effect on viscosity, smell and mildness to skin. 

    It is recommended because there isn’t much more options left. 

  • RDchemist15

    Member
    July 12, 2022 at 2:37 pm

    @Abdullah That’s fine with me, I’m ok with any chemical modification as long as it conforms to that list. It might be in the bottom of all preservatives but if its the most robust and best that will conform to that list, it’s what I’m looking for.

  • PhilGeis

    Member
    July 12, 2022 at 3:33 pm

    I continue to be amazed that (very likely) good and honest people seek and recommend as natural materials they clearly know to be synthetic as long as some self-appointed group says it’s ok.
    The amorality of fooling the rubes, who want to be fooled, confounds - but cosmetics are sold in promises - this one just more bogus.  

  • RDchemist15

    Member
    July 12, 2022 at 4:51 pm

    For the record I’m not actually advertising any of this as natural. But when a customer comes and says you can’t use X, Y, or Z (see list above) it makes the most sense to have something on hand that is the most effective and readily available. Yes, their lists are sometimes arbitrary and stupid (I’ve seen no petrolatum but mineral oil is fine) but that’s the world we work in.

  • PhilGeis

    Member
    July 13, 2022 at 7:12 pm

    Efficacy is on you.

Log in to reply.