Are these preservatives compatible with each other?

GeorgeBensonGeorgeBenson Member
edited May 6 in Formulating
I am trying to formulate a serum using very mild preservatives. Target ph is 4.5. I am thinking about trying this combination:

sodium benzoate - 0.5%
Potassium sorbate - 0.5%
Caprylyl Glycol/EHG (makingcosmetics) - 1%
Sodium phytate - 0.2 %

are any of these incompatible with each other or redundant? Or does this preservative blend even make sense? I know only getting it tested can provide me a definite answer but before I even get to that point I want to make sure this is even a good starting point. Any feedback is appreciated.

Comments

  • Confused...

    Is that two separate pairings....

    or

    You will use all 4 items together?
  • All four together!
  • PhilGeisPhilGeis Member, Professional formulator
    edited May 6
    Data offers no support for EHG beyond phenoxyethanol.

    What is the product?
  • Do you mean that EHG is not effective if it’s not used with phenoxyethanol?

    this is for an emulsified serum.
  • MarkBroussardMarkBroussard Member, Professional Chemist
    edited May 7
    @GeorgeBenson

    You might try:  Sodium Benzoate (0.5%) + Potassium Sorbate (0.2%) ... it often causes a flushing reaction, you're a bit on the high side for a leave on product.  If you can use Phenoxyethanol, then Phenxoy EHG at 1%.  If you're trying to get to a pH of 4.5, Sodium Phytate is not a good choice for a chelant since it is quite basic.  Perhaps GLDA would be a better choice if you want to formulate at relatively low pH.  If you cannot use Phenoxyethanol, Phenethyl Alcohol + Pentylene Glycol would be a good compliment.
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    See website for details www.desertinbloomcosmeticslab.com
  • @MarkBroussard
    Thanks for the tips I will try that out.

    My main reason for not using phenoxyethanol in this formula is that some people may have a reaction to it, either a real physical one on their face or an emotional reaction to the word itself. But if sodium benzoate can also cause flushing than maybe i’m not any better off with that.

    Euxyl 9010 + sodium phytate is my go to preservative for pretty much everything, I’m just trying to see if I can get away with using anything else. My normal suppliers don’t seem to carry phenethyl alcohol but I’ll keep looking.

    Is GLDA compatible with cationics?
  • MarkBroussardMarkBroussard Member, Professional Chemist
    @GeorgeBenson

    The flushing reaction is more so with Potassium Sorbate than with Sodium Benzoate, although some people can be sensitive to Sodium Benzoate.  I have not had any issues with GLDA and cationics.
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    See website for details www.desertinbloomcosmeticslab.com
  • MarkBroussardMarkBroussard Member, Professional Chemist
    edited May 7
    @GeorgeBenson

    You can source Phenethyl Alcohol from Green Line Botanicals.  To clarify what I was suggesting is:  Na Benzoate (0.5%) + Phenethyl Alcohol (0.7%) + Pentylene Glycol (2%) + GLDA (0.2%) ... you could also throw in a touch of Caprylyl Glycol (0.3%) for good measure since it is an emulsified product.
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    See website for details www.desertinbloomcosmeticslab.com
  • AbdullahAbdullah Member
    Phenoxyethanol is milder than sodium benzoate and potassium sorbate but they target different microbes. Phenoxyethanol is for bacteria and sb&ps is for fungi.

    Also i think currently phenoxyethanol is the number one most used preservative in cosmetics. It means it is well tolerated and doesn't have bad reputation for majority of people. 

    Why do you think it has bad reputation or people may have reaction with it? 
  • PhilGeisPhilGeis Member, Professional formulator
    @GeorgeBenson ;
    You need to clearly state your policy.  "Very mild" is meaningless as your not looking at irritation/sensitization data.  
    You don't like phenoxy because someone might read the label.  
    What is your policy?
  • MarkBroussardMarkBroussard Member, Professional Chemist
    @GeorgeBenson

    Abdulla is correct.  PE9010 generally causes less irritation than Na Benzoate or Potassium Sorbate.

    But, PE9010 + Sodium Phytate as the only preservation components is weak.  A better combination would be PE9010 + Sodium Phytate + Sodium Benzoate to give you better coverage on yeast/mold/fungi.

    The reputational issue as it regards Phenoxyethanol is largely driven by retailers who are increasingly putting Phenoxyethanol on the "No" list and won't carry products that contain Phenoxyethanol as opposed to irritation from Phenoxyethanol.  It all depends on what distrubtion channels GeorgeBenson is targeting.
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    See website for details www.desertinbloomcosmeticslab.com
  • Thank you, I will try these suggestions.

    personally I don’t have a problem with phenoxyethanol other than its smell, which is really not that bad just kinda strong sometimes, certainly not the worst as far as preservatives go (Tristat ECO is awful). But sometimes I dont want to have any fragrance at all, just letting the smell of my oils, butters, and hydrosols come through as much as possible. Plus I just want to experiment with different preservation methods. I see a lot of products preserved with some combination of sodium benzoate, potassium sorbate, glycols, etc. so I am trying that out.
  • SquinnySquinny Member
    @GeorgeBenson

    Abdulla is correct.  PE9010 generally causes less irritation than Na Benzoate or Potassium Sorbate.

    But, PE9010 + Sodium Phytate as the only preservation components is weak.  A better combination would be PE9010 + Sodium Phytate + Sodium Benzoate to give you better coverage on yeast/mold/fungi.

    The reputational issue as it regards Phenoxyethanol is largely driven by retailers who are increasingly putting Phenoxyethanol on the "No" list and won't carry products that contain Phenoxyethanol as opposed to irritation from Phenoxyethanol.  It all depends on what distrubtion channels GeorgeBenson is targeting.
    Hi Mark can you advise what % of each of  PE9010 + Sodium Phytate + Sodium Benzoate you would recommmend? Many thanks
  • I also use PE 9010 + some other things and have never had issue with yeast/mold....yet always have that nagging feeling I should add something for y/m.  If Sodium Benzoate is a possible irritant....is there another option...that just brings the y/m...but doesn't bring any irritation to the table?  Just looking for the best possible y/m protection...without possible irritation....(and open to synthetics).  I always formulate in the range of 4.4-5.2.
  • PhilGeisPhilGeis Member, Professional formulator
    @Graillotion
    IPBC, Chlorphenesin. 
  • AbdullahAbdullah Member
    edited May 8
    I also use PE 9010 + some other things and have never had issue with yeast/mold....yet always have that nagging feeling I should add something for y/m.  If Sodium Benzoate is a possible irritant....is there another option...that just brings the y/m...but doesn't bring any irritation to the table?  Just looking for the best possible y/m protection...without possible irritation....(and open to synthetics).  I always formulate in the range of 4.4-5.2.
    PE 9010 os ok for shampoo but for non-ionic emulsions not trustworthy for fungi. 

    Several months ago One of my lotion samples preserved with phenoxyethanol/caprylyl glycol @9/1 ratio which is kind of similar to this one did start producing gas after a month or two of production. Mr Perry said candida contamination can be the cause. So i added 0.15% caprylhydroxamic acid to see what will happen. and there was no more gas production anymore. It is stable, no smell or color change and no more gas production up to this time. 
    Although i did not use that batch after that gas production. Just keeping it for observation purpose. 
  • @Abdullah where do you source your caprylhydroxamic acid? I'd like to try it but can't find it anywhere, same with chlorphenesin.
  • AbdullahAbdullah Member
    @Abdullah where do you source your caprylhydroxamic acid? I'd like to try it but can't find it anywhere, same with chlorphenesin.
    I purchase most of my ingredients from china including caprylhydroxamic acid.

    I would suggest you use IPBC instead of caprylhydroxamic acid. I would also do so when i finish this batch of caprylhydroxamic acid that i have purchased.
  • MarkBroussardMarkBroussard Member, Professional Chemist
    Squinny said:

    Hi Mark can you advise what % of each of  PE9010 + Sodium Phytate + Sodium Benzoate you would recommmend? Many thanks
    @Squinny:  For a water-based serum:  PE9010 (1%) + Sodium Benzoate (0.35%) + Pentylene Glycol (2%) + Phytic Acid (0.2%); pH = 4.6 to 4.8

    If you're working with an emulsion:  PE9010 (1%) + Sodium Benzoate (0.35%) + Pentylene Glycol (2%) + Phytic Acid (0.2%) + Caprylyl Glycol (0.3%); pH = 4.6 to 4.8  
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    See website for details www.desertinbloomcosmeticslab.com
  • @Abdullah where do you source your caprylhydroxamic acid? I'd like to try it but can't find it anywhere, same with chlorphenesin.
    If you are looking for low quantity, you can find both ingredients here: https://www.myskinrecipes.com/shop/en/

  • SquinnySquinny Member
    Squinny said:

    Hi Mark can you advise what % of each of  PE9010 + Sodium Phytate + Sodium Benzoate you would recommmend? Many thanks
    @Squinny:  For a water-based serum:  PE9010 (1%) + Sodium Benzoate (0.35%) + Pentylene Glycol (2%) + Phytic Acid (0.2%); pH = 4.6 to 4.8

    If you're working with an emulsion:  PE9010 (1%) + Sodium Benzoate (0.35%) + Pentylene Glycol (2%) + Phytic Acid (0.2%) + Caprylyl Glycol (0.3%); pH = 4.6 to 4.8  
    Thanks so much for that Mark. Appreciate your advice. Cheers
  • MarkBroussardMarkBroussard Member, Professional Chemist
    edited May 9
    @Abdullah where do you source your caprylhydroxamic acid? I'd like to try it but can't find it anywhere, same with chlorphenesin.
    @GeorgeBenson

    Caprylhydroxamic Acid is actually a chelating agent, not really a preservative per se.  So, you can use it in a formula as a chelator to support preservatives, but don't rely on it as a preservative.

    Approach this like a math problem:

    Good Preservation = Bactericide + Fungicide + Chelator + Glycol/Diol Preservative Boosters + pH = 4.8  
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    See website for details www.desertinbloomcosmeticslab.com
  • @MarkBroussard Do you recommend a pH 4,8 only for pH-dependent preservatives, or generally for all products?
  • MarkBroussardMarkBroussard Member, Professional Chemist
    @grapefruit22

    I would recommend using pH = 4.8 for all products where that pH is feasible.  You're using low pH as a component of your preservation.
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    See website for details www.desertinbloomcosmeticslab.com
  • Squinny said:

    Hi Mark can you advise what % of each of  PE9010 + Sodium Phytate + Sodium Benzoate you would recommmend? Many thanks
    @Squinny:  For a water-based serum:  PE9010 (1%) + Sodium Benzoate (0.35%) + Pentylene Glycol (2%) + Phytic Acid (0.2%); pH = 4.6 to 4.8

    If you're working with an emulsion:  PE9010 (1%) + Sodium Benzoate (0.35%) + Pentylene Glycol (2%) + Phytic Acid (0.2%) + Caprylyl Glycol (0.3%); pH = 4.6 to 4.8  
    Would your recommendations here change if the product was in an airless container?
  • MarkBroussardMarkBroussard Member, Professional Chemist
    @GeorgeBenson

    No, an airless pump container would be considered the preferred packaging component of your preservation system.  These are the essential elements of a good preservation system, packaging included.  The respective preservative system component ingredients are inexpensive, what take a risk when you don't need to?
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    See website for details www.desertinbloomcosmeticslab.com
  • @MarkBroussard great, thanks! Would it be alright to swap phytic acid for GLDA? 
  • MarkBroussardMarkBroussard Member, Professional Chemist
    @GeorgeBenson

    Yes, you can use any chelant of your choice, just make sure that you use one.
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    See website for details www.desertinbloomcosmeticslab.com
  • SquinnySquinny Member
    Hi Mark what about Disodium EDTA as a swap for the Phytic Acid? And if so what % to use? Or Sodium Phytate? Many thanks and if this is a stupid question let me know. 
  • PharmaPharma Member, Pharmacist
    Phytic acid is mostly sodium phytate wrongly labelled as phytic acid.
    I don't see a reason why you couln't swap it.
  • MarkBroussardMarkBroussard Member, Professional Chemist
    @Squinny

    Yes, you can use Disodium EDTA, Phytic Acid or Sodium Phytate.  Generally in the range 0.1% to 0.2%.  Be aware that if you use Phytic Acid it will shift your pH down and if you use Sodium Phytate it will shift your pH up, so add them while measuring the pH.
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    See website for details www.desertinbloomcosmeticslab.com
  • SquinnySquinny Member
    Great thanks so much Mark very helpful. Cheers
  • Squinny said:

    Hi Mark can you advise what % of each of  PE9010 + Sodium Phytate + Sodium Benzoate you would recommmend? Many thanks
    @Squinny:  For a water-based serum:  PE9010 (1%) + Sodium Benzoate (0.35%) + Pentylene Glycol (2%) + Phytic Acid (0.2%); pH = 4.6 to 4.8

    If you're working with an emulsion:  PE9010 (1%) + Sodium Benzoate (0.35%) + Pentylene Glycol (2%) + Phytic Acid (0.2%) + Caprylyl Glycol (0.3%); pH = 4.6 to 4.8  
    Hi Mark, would Propanediol 1,3 work instead of Caprylyl Glycol? I have it in my formula at 2% already. Thank you. 
  • MarkBroussardMarkBroussard Member, Professional Chemist
    @Anca_Formulator

    Yes, Propanediol would function as a preservative booster.  Caprylyl Glycol is a bit better as it's mode of action is to help weaken the microbial cell wall, but it does reduce viscosity in creams.
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    See website for details www.desertinbloomcosmeticslab.com
  • @Anca_Formulator

    Yes, Propanediol would function as a preservative booster.  Caprylyl Glycol is a bit better as it's mode of action is to help weaken the microbial cell wall, but it does reduce viscosity in creams.
    Just curious @M@MarkBroussard, I would not assume Propanediol and CG would be swapped at a 1:1 basis (as far as hurdle technology is concerned).  How much Propanediol would you guess would be needed to replace .3% CG?  I actually use both.... CG at .25% (with Hexanediol also at .25%) and my Propanediol levels typically run at the 1.5-2% range.

    For the most part I am using Propanediol as a glycerol reducer.
  • MarkBroussardMarkBroussard Member, Professional Chemist
    @Graillotion

    Yes, I typically used Propanediol at 3%.  Caprylyl Glycol at 0.3%.
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    See website for details www.desertinbloomcosmeticslab.com
  • Thank you Mark. 

    @MarkBroussard What are your thoughts on Jeecide CAP 2(by Jeen): Caprylyl Glycol (and) Phenoxyethanol (and) Hexylene Glycol?
  • edited May 21
    @MarkBroussard ;  Can the Euxyl 9010 Hurdle approach above be effective for a toner made with 50% organic hydrosol (from a reputable source, with a COA, but unpreserved by manufacturer) that also contains some hydrolized protein extracts? Has 5% glycols. 
  • MarkBroussardMarkBroussard Member, Professional Chemist
    Thank you Mark. 

    @MarkBroussard What are your thoughts on Jeecide CAP 2(by Jeen): Caprylyl Glycol (and) Phenoxyethanol (and) Hexylene Glycol?
    Yes, this would work in emulsified products.  You would need to couple it up with Gluconolactone (and) Sodium Benzoate
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    See website for details www.desertinbloomcosmeticslab.com
  • MarkBroussardMarkBroussard Member, Professional Chemist
    @MarkBroussard ;  Can the Euxyl 9010 Hurdle approach above be effective for a toner made with 50% organic hydrosol (from a reputable source, with a COA, but unpreserved by manufacturer) that also contains some hydrolized protein extracts? Has 5% glycols. 
    Sure, but you need to couple it up with Gluconolactone (and Sodium Benzoate, chelator, low pH, but it should work
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    See website for details www.desertinbloomcosmeticslab.com
  • Thank you!
  • @MarkBroussard ;  Can the Euxyl 9010 Hurdle approach above be effective for a toner made with 50% organic hydrosol (from a reputable source, with a COA, but unpreserved by manufacturer) that also contains some hydrolized protein extracts? Has 5% glycols. 
    Sure, but you need to couple it up with Gluconolactone (and Sodium Benzoate, chelator, low pH, but it should work
    I can only find Gluconolactone as part of Geogard Ultra powder (Gluconolactone (and) Sodium Benzoate). If that works, what percentage for the toner (supplier says 0.75% - 1.5%)? 

    Thank you. 
  • MarkBroussardMarkBroussard Member, Professional Chemist
    @Anca_Formulator

    If you use 1% PE9010 + 1% Geogard Ultra + 3% Pentylene Glycol + pH =4.8, you will be in good shape
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    See website for details www.desertinbloomcosmeticslab.com
  • Thank you Mark!!
  • PaprikPaprik Member
    I think everyone should say a huge THANK YOU for Mark's time and for sharing his amazing knowledge! We all can learn something new and we do (at least I do) very much appreciate it. So thank you @MarkBroussard :) 
  • SquinnySquinny Member
    Totally agree :)
  • @MarkBroussard Hi Mark, I followed your suggestion of 

    1% Euxyl PE9010 + 1% Geogard Ultra + 0.2% sodium phytate + 2% Propanediol + 3% Pentylene Glycol + 4.8 pH   for 200 g Toner

    I added the Geogard Ultra powder last, and stirred with the magnetic stirrer for 15 minutes, I also tried heating it, but I just couldn't get the Geogard to fully dissolve. I did some research and it seems that a lot of people have this issue with Geogard Ultra. 

    Is there something else I can use in its place that's more user friendly?

    Thank you
  • MarkBroussardMarkBroussard Member, Professional Chemist
    @Anca_Formulator

    Geogard Ultra generally goes into soluton fairly easily.  Try adding it first.
    Chemist/Microbiologist formulating in the Organic & Naturals arena under ECOCert/Natural Products Assn/Whole Foods/National Organic Program guidelines focused skincare & haircare products. 

    See website for details www.desertinbloomcosmeticslab.com
  • @MarkBroussard: Thank you. i will try that. 
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