Combining Preservatives - Germall Plus and Euxyl

So I know each preservative has its strengths and weaknesses, therefore I am interested in combining 2 preservatives (in addition to using GMP.) I already use Liquid Germall Plus and have for many years, but I am interested in adding Euxyl 9010.

Are there any concerns regarding the combination of 0.5% Liquid Germall Plus and 0.5% Euxyl 9010? There are no ingredient overlaps. I wanted to check with you all just in case I'm missing something.

I also use 0.1% Disodium EDTA. 

Thank you in advance.
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Comments

  • PhilGeisPhilGeis Member, Professional formulator
    Euxyl 9010 (phenoxyethanol) targets Gram negative bacteria - as does Germall.  they overlap in efficacy.  Are you seeing issues wiuth  Gram negative's? 
  • PhilGeis said:
    Euxyl 9010 (phenoxyethanol) targets Gram negative bacteria - as does Germall.  they overlap in efficacy.  Are you seeing issues wiuth  Gram negative's? 
    No, just want to achieve a really robust preservative system. I'm intrigued by Euxyl because it is advertised as being able to kill bacteria in a product that is already contaminated. I use GMP but I do formulate with extracts, hydrosols, etc. Ingredients that can be difficult to preserve. I'm okay with overlap as long as there are no issues. 
  • PhilGeisPhilGeis Member, Professional formulator
    Don't bet on killing bacteria in contaminated product.    How does the Germall+/EDTA perform in chaloenge?
  • I'm not betting on it, as I said I always use GMP but on the off chance that one of my ingredients is contaminated, I like the idea of Euxyl as I do use a lot of botanicals. 

    I haven't tested my products because I only make skincare for myself and friends/family, for now. I want to sell in the future which is why I'm researching preservative combinations.
  • chemicalmattchemicalmatt Member, Professional Chemist
    Not often I get to add to Dr. Phil Geis' comments (I am a fan) but I will: Germall Plus is broad-spectrum having the IPBC in there and one of the best you can use. My opinion, and Phil can add here, is the Euxyl may be turbocharging your anti-bac efficacy with the phenoxyethanol and only marginally adding to the antifungal activity. Euxyl is no harm, no foul, but maybe unnecessary.
  • PhilGeisPhilGeis Member, Professional formulator
    I'm with chemicalmatt!
  • Thank you both so much! 
  • I will use a chance to throw my question too as we are lucky to have two experts here. I often combine germall plus and phenonip. The reason being, I buy ingredients from repackagers, and you can’t trust them on storing ingredients properly (I saw things like coconut oil in a ziplock bag and photosensitive materials in a transparent bottle). Also they decant ingredients million times allowing dust and bugs in. So I just assume all ingredients are compromised from day 1. Is there any reason not to do this. I figured there are no overlapping compounds in these two preservative blends so I won’t go over recommended limit. Thank you in advance @PhilGeis and @chemicalmatt
  • PhilGeisPhilGeis Member, Professional formulator
    You  mak verye reasonable points.  My experiecne was with a big company that could demand quality materials.  I  used single components so that I could adjust/titrate concnentrations if needed.
  • Thank you. I understand it’s a bit overkill but unfortunately cosmetic formulation as a hobby has limitations when it comes to sourcing materials (both price and quality).
  • I will use a chance to throw my question too as we are lucky to have two experts here. I often combine germall plus and phenonip. The reason being, I buy ingredients from repackagers, and you can’t trust them on storing ingredients properly (I saw things like coconut oil in a ziplock bag and photosensitive materials in a transparent bottle). Also they decant ingredients million times allowing dust and bugs in. So I just assume all ingredients are compromised from day 1. Is there any reason not to do this. I figured there are no overlapping compounds in these two preservative blends so I won’t go over recommended limit. Thank you in advance @PhilGeis and @chemicalmatt
    When you say "bug food", what do you mean by it? What ingredients fall under this category of ingredients?
  • PerryPerry Administrator, Professional Chemist
    "Bug food" is any ingredient on which microbes can eat and grow. This can be sugars, carbohydrates, proteins, or a variety of other hydrocarbons found in cosmetics formulas. 
  • PhilGeisPhilGeis Member, Professional formulator
    and they don't even need much "food" as bugs (esp. Gram negatives like cepacia) can contaminated purified water systems.
  • A couple of very common examples: plant extracts, hydrolyzed proteins, aloe (deserves its own place I think), lecithin, and clays. And obviously anything that can be classified as food: milk, honey, fruit and vegetable purées (hello Lush) and similar claim ingredients that don’t do anything beyond being fairy dust.
  • @PhilGeis Dr. Geis, it always fascinated me how some bacteria manage to multiply in steam distilled water. 
  • PhilGeisPhilGeis Member, Professional formulator
    edited December 2020
    @PhilGeis Dr. Geis, it always fascinated me how some bacteria manage to multiply in steam distilled water. 
    Yes!  Even more bizarre - raw materials: fungal (Penicillim spores) contamination citric acid, ZPT suspension for antidandruff shampoo with P. aeruginosa, concentrated disinfectant quat active raw material with P. aeruginosa, B. cepacia in 70% ethanol (not mine - in literature).

    products: colonies of Kurthia sp. isolate in/on soap bar (with milk), Bacillus sp. isolate in pH 9 built hard surface cleaner, Halomonas in high pH liquid laundry 
  • PhilGeis said:
    @PhilGeis Dr. Geis, it always fascinated me how some bacteria manage to multiply in steam distilled water. 
    Yes!  Even more bizarre - raw materials: fungal (Penicillim spores) contamination citric acid, ZPT suspension for antidandruff shampoo with P. aeruginosa, concentrated disinfectant quat active raw material with P. aeruginosa, B. cepacia in 70% ethanol (not mine - in literature).

    products: colonies of Kurthia sp. isolate in/on soap bar (with milk), Bacillus sp. isolate in pH 9 built hard surface cleaner, Halomonas in high pH liquid laundry 
    Isn't nature fascinating!! And frustrating too 😆
  • I will use a chance to throw my question too as we are lucky to have two experts here. I often combine germall plus and phenonip. The reason being, I buy ingredients from repackagers, and you can’t trust them on storing ingredients properly (I saw things like coconut oil in a ziplock bag and photosensitive materials in a transparent bottle). Also they decant ingredients million times allowing dust and bugs in. So I just assume all ingredients are compromised from day 1. Is there any reason not to do this. I figured there are no overlapping compounds in these two preservative blends so I won’t go over recommended limit. Thank you in advance @PhilGeis and @chemicalmatt
    You mention "storing ingredientats" and this is something I am currently in the middle of researching as I need to rearrange and figure out the most efficient way to store my ingredients...do you have a system down for storing your ingredients that works and that prevents ingredients from going bad before their expiration date? 
    If this needs to be started as a new discussion, I totally understand....just curious as I am in dire need of a system to store my ever growing ingredient stores!
  • PharmaPharma Member, Pharmacist
    A fridge or even better a freezer would be great ;) .
  • PhilGeisPhilGeis Member, Professional formulator
    edited April 13
    Suggest folks deal with competent suppliers who tell you how and how long to store raw materials. Excessive heat and excessive cold can both compromise a raw material. I recall cosmetic manufacturer who stored drums of preservative solution at less than specified temp. Active fell out of solution leaving ingredient addition nothing but solvent - and product unpreserved and contaminated.
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