# Adding Glycerin to products, need preserved?



## Pink

Hello, this is my first post and I would like to first say I absolutely love this forum! :razz:  I have been a lurker for so long and thought it was about time to make an account.

I have a question about adding Vegetable Glycerin to certain bath and body products.  I have read on this forum, a couple different posts, about people saying that when Glycerin is added to things that it should be preserved with a broad spectrum preservative.  I honestly never heard of this or knew this.  Even though it's "water soluable", I always thought it was similar to oils being added to recipes, and it didn't need any type of additional preservation.  I started trying to find information over the internet and haven't found anything either on this subject.

So my question is, does adding Glycerin need a preservative when water isn't added to a recipe?  For example, I make lipgloss and bath bomb melts( a bath bomb with extra oils).  In both of those products, I add probably around 10% of glycerin.  From reading those posts, I'm worried if adding the glycerin could make my product "go bad" faster.:shifty:


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## Genny

Since glycerin is a humectant, it draws moisture into the product, so yep it does require a preservative when using it.


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## Pink

Hi Genny.  Thanks so much for your reply.  If I remember correctly the posts that I saw about this concern was from you stating it.  I completely see your reasoning behind using a preservative since Glycerin is a humectant.  I just can't find any credible information about this on the internet.  I have searched all day today and have not found a recipe or anything saying that a preservative is needed when Glycerin is added to a product.

I know all the recipes I find from reputable people and companies also do not have preservatives in recipes that contain glycerin.  Just for example this one..  http://www.pvsoap.com/recipe_massage_balm.htm

When making bubble bars, one of the main moistening ingredients that a lot of people use is glycerin to help keep them softer so they can be crumbled under the water.  I also have not seen a recipe or anyone that makes them use a preservative either.

I guess I'm just making myself even more confused LOL!  Do you happen to remember where you found or heard this info of needing to add a preservative for glycerin?  Just wanting to find some credible info.  Thanks for letting me pick your brain


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## melstan775

What Genny means Pink,is humectants draw in moisture. Where there is moisture there is water. Water is where bacteria comes from, not necessarily the glycerin or other proteins or powders used in cosmetics. You add the preservative to prevent bacterial growth, or even mold, from warm-wetness, like water clinging to stuff. If you'r going to use your products within a few days of making of them, you probbly can get away without a preservative. There is a blog about this topic... I can't think of it right off hand, but it's one they reference a lot. It's green, the girl is Australian I think, and she talks a lot about why you do this. If I find it I will post it, otherwise I am sure someone else will know it right off.


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## Pink

Thanks for your reply Mel.  Yes I understood the whole moisture thing.  Which absolutely makes sense.  I've just been searching for hours on this subject for some credible info and I can't come up with anything other than what I have seen on this forum.  Thanks for your help :grin:


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## melstan775

you're welcome. If I find the blog I will post the link. I can't remember it off the top of my head and I Can't find it in my bookmarks just now.


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## bodhi

Just because something is a humectant it doesn't mean it automatically need a preservative.  Examples are also salt, sugar, clay, etc.  Also, glycerine is shelf stable in itself and is also a preservative.  I would doubt there would be any negative effects on bath bombs or lip balms by adding glycerine.  The bombs are basically citric acid and salt, right?  And the lip balm, its oils with no water, yes?  I dont think adding glycerine will hurt either or necessitate a preservative.  I would be very interested to see any scientific evidence to the contrary though.


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## Lindy

ahhhh the Preservative debate - one more time with feeling.

Pink I must ask you.  Why are you asking a question that you have already made up your mind on?  The site you linked to demonstrates an amateur recipe because any bath & body maker worth their salt, or actually even knows what they are doing always creates formulations in weight rather than teaspoons and tablespoons.  Those types of measurements are reserved for cooking and baking.

So yes this sounds rather snarky, but please, if you don't want to know the answer, then don't ask the question.  And the answer to your question is that any product that contains added glycerin, with the exception of soap, requires a broad spectrum preservative, end of story.

Cheers


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## bodhi

Hi Lindy, Could you post a link to validated information about the need to add a preservative when glycerine is added to a product?  I think it could really help clarify this for anyone who reads this thread and shed some light on situations where maybe a preservative is proven to be needed with glycerine.

Here is a link to information I have found about glycerine in cosmetic products:  http://www.fda.gov/iceci/inspections/inspectionguides/ucm074952.htm 

In this link, the FDA states that some cosmetic products can be preserved with the addition of 10% glycerine. 

I referenced this one because the OP was asking about adding 10% of a product that does not support microbial growth to other products that do not support microbial growth. 

Here are two common FDA regulated over the  counter drugs - Fleet Enemas and Proetz Nasal Sprays.  Both of these are glycerine and water formulas meant specifically to  be introduced into body cavities.  Neither contain other preservatives.


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## Genny

Pink ~ I can't honestly remember exactly where I learned about it.  It's been a long time.  It could have been at Susan's blog http://swiftcraftymonkey.blogspot.com/ which is a wealth of information about preservatives.  Seriously, great info there.  
Or it could have been on The Dish Forum from a few members who had their products tested, which I can't check right now because they're having some issues & are down right now.  There recently was a member who tested different kinds of honey for bacteria because of so many people that use it in lip balms as a sweetener.  It did indeed contain many kinds of bacteria.  A lot of people ended up dropping it from their lip balms.

Also, even though PVsoaps is a reputable supplier, their recipes on there are really awful.  I saw lotion recipes on there where they tell you to add several TBSPs of ingredients (milk, honey, wheat products, glycerin, etc) to 6-7 oz of premade lotion base.  There is absolutely no way that the preservative in that lotion base will be able to cover all of those extras.
They also repeatedly refer to Vitamin E as a preservative, which it is not.  Also saw a recipe for homemade sunscreen.  That's a lawsuit waiting to happen.

Also, I've heard from so many soapers that have premixed their powdered colorants with glycerin only to have them grow mold after a short while.

If you try the recipe from PVsoaps that you linked to, I'd use an emulsifier (at least beeswax), because without one, the glycerin absolutely will separate.


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## Genny

bodhi ~ According to another link on the FDA, a product would require 50% or more glycerin to not need a preservative. So they seem to be contradicting themselves.  Although in the link that you posted, I do see that they mention self-pressurized containers, maybe that's the key?
http://www.fda.gov/ohrms/dockets/ac/02/slides/3840s1_09_slater_Glycerol/sld016.htm


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## Pink

Lindy, I'm not really for sure why you are calling this a debate.  And also stating that I "made up my mind".  I believe you might of taken this post the wrong way.

The whole point of this post is because I am now unsure, so I am wanting to get some insight, not argue.  Like I said, I just have not found any concrete evidence saying this other than on this forum.  So that is why I am here, on this forum, to ask.  I have some products that I make with glycerin in it and now I am obviously concerned if it's necessary to add a preservative now.  

Also stating that I "don't want to know the answer" is completely false.  As well as the "amateur" recipe you stated, was just an example of something a lot of different crafters out there might be making and not realizing if it needs a preservative or not.  It was purely an example of what I am gathering everywhere.  I guess I must be an amateur as well, because I have some crafted recipes that I use both weight measurements as well as volume measurments roblem:  Thanks for your insight tho.  And I now know you feel that a preservative does need to be used.  So thank you, but I definitely could of done without the rude attitude.

Bodhi, Thanks for your replies and that link.  I'm also wanting to shed some light on this as well as help others like myself that have all along not known this. 

Genny, Thanks again for your replies.  :-D And I do want to apologize if my earlier posts sounded like I was trying to debate you or being rude.  I really am just wanting to find the truth to this so I can have peace at mind.  I have went to that blog a lot for great info as well!  I also tried getting on the The Dish Forum, and saw it was down yesterday because while searching it did pull up a few posts of people talking about it as well.  I will keep searching.

I use premixed colorants with the glycerin from different companies and I know they state to use them within a year.  Never had a problem with any molding tho.  So obviously I am concerned with using those in recipes now as well.  Again thanks for your info!


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## Genny

Pink said:


> Genny, Thanks again for your replies.  :-D And I do want to apologize if my earlier posts sounded like I was trying to debate you or being rude.
> 
> I use premixed colorants with the glycerin from different companies and I know they state to use them within a year.  Never had a problem with any molding tho.  So obviously I am concerned with using those in recipes now as well.  Again thanks for your info!



I didn't think you were being rude.  

There are a couple suppliers (I'll see if I can find them) who do add preservatives to their glycerin based colorants.


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## bodhi

Genny said:


> bodhi ~ According to another link on the FDA, a product would require 50% or more glycerin to not need a preservative. So they seem to be contradicting themselves.  Although in the link that you posted, I do see that they mention self-pressurized containers, maybe that's the key?
> http://www.fda.gov/ohrms/dockets/ac/02/slides/3840s1_09_slater_Glycerol/sld016.htm




Thanks for the link Genny,  it doesnt want to open for me so ill look at it later.  That would make sense too, as glycerites can require up to 70% to preserve water solutions.  Those are opened containers though, so it seems it depends on the concentration as well as other ingredients and sometimes packaging.  Looks like the salts might be a reliable combo with glycerine.  

Sorry for hijacking the thread Pink!  Learning in progress


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## Genny

Also, for anyone who wants to be safe & make sure their preservative is working or if they should use a preservative, I highly recommend getting it tested.  You can get a basic microbial test at Sagescript.
http://www.sagescript.com/microbiology


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## Pink

bodhi said:


> Sorry for hijacking the thread Pink!  Learning in progress




Your definitely not highjacking Bodhi.  I encourage it!  Love all the info   I'm trying to learn as well, Thanks!


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## DeeAnna

A product in a sterile one-use container (enema) and a sterile product in controlled access container (nasal spray) cannot be directly compared to personal-use products manufactured in sanitary but non-sterile conditions and packaged in containers that often do not prevent product contamination by the consumer. 

Even if a product is microbially safe at the point of sale, there is no way to control contamination from wet fingers, bacteria laden lips, mold from damp showers, etc. Preservatives make sense even if you only view them as insurance against product contamination during normal consumer use.


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## Lindy

Okay let me reply step by step.

*Pink* - There is a huge difference between glycerin and glycerite (google the definitions).  Glycerin (http://www.paulaschoice.com/cosmetic-ingredient-dictionary/definition/glycerin) is a type of sugar that is extracted from plants and is a humectant which in short attracts water.  Whenever water becomes present in a formulation then preservatives become necessary.  A Glycerite (http://www.thefreedictionary.com/Glycerite) is a product created by extracting properties from plants using glycerine which again is going to attract water into your formulation which is again going to require preservative.

My problem here is that every time someone said you needed a preservative you wanted to discuss their answer to get further proof.  You also need to understand that (and this is not your fault) we see sooooo many hobbyists that come in here to try and get us to agree they don't need preservatives because they have already made up their mind.  Your posts were indicating the same mindset.  Since you are looking for irrefutable proof that preservatives are required then you need to start reading information on some of the formulator sites that are reputable and professional rather than a hobbyist page. *HERE* is a wonderful resource for some recipes to look at.

Preservatives are not a swear word, they are not evil, they protect you, your family, friends and eventually your customers should you decide to start selling.  Glycerin _*is not a preservative*_, it does not have the ability to preserve unless you are using huge amounts.

I will add that if you are using airless containers the necessity of a preservative is lowered but remember, a preservative is going to hold the product in the condition that it is in at the time of adding that preservative so if there are already contagions in there it will not destroy them.  So if mold is already present it is not going to kill it which is why when we are making lotions and body products we use a heat and hold method in order to give our lotion it's very best chance to remain stable over time.

*Bodhi*, I am not sure what you are asking me.  You want me to find something that says glycerin needs to be preserved?  In itself and by itself, no I don't believe it needs to be but you are buying it as a whole product you are not making it yourself.  Common sense has got to come into play at some point.  Do you really want to risk making a product that is going to draw water to your product which will compromise its stability and not have a preservative in there to protect yourself and your family?  Just because you can't see bacteria, or mold spores, or fungus doesn't mean it isn't present.  That's why products like this need to be tested whether you are challenge testing or buying a reliable testing kit.

The problem preserving a mostly oil based product is that the most effective preservative in that environment is parabens and we know what the fear mongerers have done to that.  So we don't use parabens.  We then have to start looking at preservative system that is going to work in an oil environment.  They are out there you just have to do the legwork to find them.

Because glycerin is a sweetener/sugar it is going to attract things that grow and again, in pure form I don't believe it requires a preservative however I don't know if there is one already in the product when we receive it.  As mentioned to Pink, go to the link on formulations and take a look at what they are doing. 

The comment that 50% + glycerin will be a preservative is correct, but are you really going to use that much?  *HERE* is a post on Swift Craft Monkey's blog on that exact question.

****************************
Yes I get cranky when I see people come in wanting to be told they don't need a preservative and *Pink* I took you as one of these types of people because you weren't accepting the answers given.​


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## melstan775

Genny said:


> Pink ~ I can't honestly remember exactly where I learned about it.  It's been a long time.  It could have been at Susan's blog http://swiftcraftymonkey.blogspot.com/.



That's the blog I was thinking of before. Thank you for knowing it Genny. It's been driving me nuts !


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## Genny

melstan775 said:


> That's the blog I was thinking of before. Thank you for knowing it Genny. It's been driving me nuts !



LOL Isn't it annoying when that happens?


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## bodhi

Hi Lindy, Your statement was that all products with glycerine need a  preservative.  I asked if you had any studies or reputable sources  stating that, so that we could learn about this also.  

Thank you for the link to the blog.  One link references another blog  and the other references a regulation on multi dose oral and injectable  vaccines and allergy injections.  I quoted the regulation below.  

Im not sure where you got your information on glycerites or glycerine, but it is not  correct.   

Glycerites do not need and do not contain additional  preservatives and can be stable for decades whether opened and used or  not.   

Liquid  pharmaceutical drugs are preserved with glycerine in concentrations as low as 18%  because glycerine is a preservative.  This includes cough medicine which is often chugged right from the bottle by people sick with all kinds of bacterial nasties.

Genny, Thanks for the link.  I was able to open it and it is talking  about allergy injections.  Here is the part of the Federal regulation on  vaccines that it was referencing:  

Products in multiple-dose containers shall  contain a preservative, except that a preservative need not be added to  Yellow Fever Vaccine; Poliovirus Vaccine Live Oral; viral vaccines  labeled for use with the jet injector; dried vaccines when the  accompanying diluent contains a preservative; or to an Allergenic  Product in 50 percent or more volume in volume (v/v) glycerin.

Here is a quote from the FDA about cosmetics which states that a cosmetic containing more than 10% glycerol is self preserving:

Some cosmetics, i.e., those containing more than about 10% ethanol,  propylene glycol, glycerol, etc., and cosmetics in self-pressurized  containers, are self-preserving and are not likely to become  contaminated with microorganisms.

So, i guess i am still wondering where the  information came from that all products containing glycerine need a  preservative because it attracts water and is a sweetener.  I am personally back to this;  I  dont believe the products the OP asked about which would not normally  support bacterial growth would with the addition of 10% glycerine.  If  they wouldnt support growth without glycerine, there is no reason they  would with a little added in.


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## Genny

bodhi said:


> So, i guess i am still wondering where the  information came from that all products containing glycerine need a  preservative because it attracts water and is a sweetener.  As far as i  can find, this is incorrect.  So i guess, im personally back to this;  I  dont believe products the OP asked about which would not normally  support bacterial growth would with the addition of 10% glycerine.  If  they wouldnt support growth without glycerine, there is no reason they  would with a little added in.



Those products without glycerine wouldn't normally support bacterial growth because there's no water in them.  But when you add glycerine, glycerine can attract moisture/water into the product.  That's where the bacteria will grow, is in that water, not in the glycerine.

It has nothing to do with the fact that it's a sweetener, it's the humectant part that's the problem.


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## Genny

P.S. I'm doing a small experiment with shea butter & vegetable glycerin.  I just started it yesterday, so I'll see how it goes.


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## bodhi

Genny said:


> Those products without glycerine wouldn't normally support bacterial growth because there's no water in them.  But when you add glycerine, glycerine can attract moisture/water into the product.  That's where the bacteria will grow, is in that water, not in the glycerine.
> 
> It has nothing to do with the fact that it's a sweetener, it's the humectant part that's the problem.



Agreed about bacteria sometimes being able to grow in water, but just because it can grow in water does not mean that it will.  Glycerine is an alcohol and binds its own weight in water, and even if it didnt, in  the case of a bath bomb, the salts and citric acid would prevent any  growth, and in a lip balm, the oils or butters would.  

If the logic  is that adding a humectant to a product will cause bacterial  growth, then any product with salt or propylene glycol would need  an additional preservative because even though they are  preservatives, they are also humectants.  And in the same line of thinking any product that is a humectant including the salt and sugar in everyones kitchen needs a preservative because it is drawing water out of the air and growing bacteria.  

So even if you ignore the FDA, and the pharmaceutical industry, it just isnt sound logic, or science.


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## bodhi

Genny said:


> P.S. I'm doing a small experiment with shea butter & vegetable glycerin.  I just started it yesterday, so I'll see how it goes.



Let us know how it turns out.


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## Genny

bodhi said:


> Glycerine is an alcohol and binds its own weight in water, and even if it didnt, in  the case of a bath bomb, the salts and citric acid would prevent any  growth, and in a lip balm, the oils or butters would.



Most bath bombs don't have salt in them, just baking soda, citric acid & something wet to hold them together.   Also, bath bombs that contain citric acid absolutely do grow mold on them due to humidity.
http://www.soapmakingforum.com/f19/what-happened-1988/
Plus, the company Lush is notorious for having moldy bath bombs.

I just read this afternoon that at 45% glycerine can lower the water activity of a product.  I can't remember where I read it,  I think it was on aqualab.  But that would be way too much glycerine for a lip balm or bath bomb.

But another problem with adding glycerine to lip balms is that it doesn't incorporate into oil/butters without using an emulsifier, which most people don't do.  So, it just seeps out.  Even if it doesn't seep out right away, it will over time.

That's fine if you think that non-water products don't need a preservative.  Then don't add them to your products.
I'm going to stand by my opinion that if you add a humectant to a product, add a preservative.  I'd rather not take the chance of someone getting staph infection.


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## bodhi

I cant comment on the thread or lush because I dont know how they were made or if ingredients may have been contaminated or any number of things, but baking soda is a salt and it kills mold so that is rather interesting.  

I dont think i said that products that dont contain water do need or dont need a preservative.  My comments were that if the material didnt need a preservative to begin with, then the addition of the glycerine wouldnt change that-because glycerine is a preservative. 

Yes, glycerine lowers water activity.  Decreased water activity equals decreased microbial potential equals preservative.  I think its in lunch meats at 1 or 2%.  

 Anyway, hope your lip balms turn out nicely.


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## Lindy

Bodhi since you seem determine to prove your science, perhaps you can share you background with us that gives you this knowledge.  You're rather new to the forum and we haven't yet had the opportunity of getting to know you.


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## Pink

Such great info! Thank you Bodhi, Genny, and Melstan for all your insight and helpful information.

I actually do add in some salts with my bath bombs as well as the citric acid, soda, etc. I've never heard of a bath bomb growing mold, but I'm sure depending on where its stored and how its made, it certainly could eventually. I'm just wondering on that post if they were experiencing "warts" from the reaction of high humidity.

IDK, anyway back to the glycerin. I did happen to read for a couple hours on the craftymonkey blog the other day. I did find two small areas where she stated to add a preservative. One was a recipe she had written down and stated that since there's water activity in it, that it would need a preservative. The recipe didn't have water as an ingredient, so I'm assuming she meant the glycerin that she had written down as the ingredient. The other was a reply to a post. Someone had written down their recipe that contained water and glycerine. They asked her if they was to replace the water with something else, would they still need a preservative. Which she replied yes because it contains glycerine. Thats just in two small sections that I happened to catch and she doesn't really go into detail about it being added in smaller amounts in products without water.

I did also send a message to the lovely ladies over at soap queen. I did get a response back that they would recommend adding a preservative since it is a humectant. But then again I had seen back in their older blogs, they still have a recipe up for a lip balm which contains glycerine without an added preservative. Even though they later commented on that exact recipe that the glycerine didn't mix in real well.

Then I find this... http://www.diycosmetics.com/pages/Are-Preservatives-Necessary.html Where it states "*GLYCERIN: *glycol will also bind to the water making it unavailable to microorganisms". Which is what I had pretty much gathered from several resources before, when I decided to add glycerin in some of my products. Also when buying some premade glycerin pigments to be added in different products (which a lot of us do) and not hearing anything about needing a preservative when adding those into products.

There is all sorts of conflicting information out there thats making my head spin :crazy: Normally when I do research on things like this, you can always sort out the not true, and the true. On this subject I can't. It might just be one of those things that you can argue about til your blue, and just have to make your own "personal" decision. Or just simply have to take your own action into getting a recipe tested to find out.

I may next week contact the FDA about their website talking about using 10% glycerine, and see what they have to say. If they even will give me any helpful info.

Genny, I'm definitely curious on the shea butter and glycerin experiment. Was you planning on testing it with a home kit? And if so, can you tell me what you use?


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## bodhi

Lindy said:


> Bodhi since you seem determine to prove your science, perhaps you can share you background with us that gives you this knowledge.  You're rather new to the forum and we haven't yet had the opportunity of getting to know you.



It isn't My science Lindy, it is Science.  There is no need to prove it as this has already been done by the medical, pharmaceutical, food service and cosmetic industries.  The information is available to anyone interested in educating themselves beyond what is offered by a biased salesperson.  

My background is irrelevant, but since you asked, it's in Medicine.  What is yours?


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## DeeAnna

I have been following this thread with some interest, but I have to say the conversational tone is now beginning to feel rather unkind and unhelpful. I think it might be best to allow this discussion to expire with as much grace as can be managed at this point. --DeeAnna


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