Sunday, January 8, 2017

Weekend Wonderings: Other names for ingredients? Will this preservative be effective for this product?

In this post, Road trip essentials: Solid scrub bars, Neha asks: Can I use sodium benzoate as a preservative in emulsifying sugar scrub? My local vendor is unable to understand optiphen. Or can you help me with any other name for this preservative?

If you want to know more about preservatives, the first thing to do is consult the preservatives section of this blog. In that section, you'll notice I have general information about what we find in preservatives, a list of preservatives we can buy by name, and a downloadable chart, amongst other things.

If you click on "organic acids" - which I get might not be an obvious place to look - or search for "sodium benzoate", you'll reach this post on the topic. And here's what I wrote about it...

Sodium benzoate, a salt of benzoic acid, was the first chemical preservative allowed by the FDA for food products. It converts to benzoic acid, which is a good anti-microbial and fungicidal preservative, when it's in an acidic mixture. (Benzoic acid isn't very water soluble, so we use the sodium benzoate in water so it will dissolve and become benzoic acid.)

Sodium benzoate is bacteriostatic, which means it limits the growth of bacteria by messing with its metabolism, but doesn't kill it. It is also a recognized fungicidal ingredient.

The main problem in using sodium benzoate in our products is the pH level - sodium benzoate works best at pH 5 or less (possibly 6 or less), which means its use is limited to products more acidic products like toners or moisturizers with AHA or salicylic acid. You definitely want to own a pH meter if you're using this as your main preservative! Sodium benzoate is approved for us at up to 0.1% for food products and up to 1.0% for cosmetic and medicinal products. You don't want to use this with Vitamin C as studies have shown that together they can form benzene, which is carcinogenic. Geogard Ultra contains sodium benzoate as its preservative.

Reading this, does it seem like a good choice for an emulsified sugar scrub? No, because it isn't a broad spectrum preservative. (A broad spectrum preservative is one that kills off bacteria, mould, yeast, and other fungi. The preservatives we buy are called synergistic preservatives, which are combinations of preservatives intended to eliminate all the various contaminants we could see in our products.) We want something that protects us from all kinds of contamination, not just one or two types.

The other reason is that an emulsified sugar scrub is not acidic enough. Its pH is definitely above 5, which means sodium benzoate won't work well.

What could you use as a preservative? Is Optiphen a good choice? Again, check out the post I've written about it, then the update post on the topic as it relates specifically to scrubs. Optiphen isn't a broad spectrum or complete preservative as it doesn't contain a fungicide, so you'd have to combine it with something else.

A quick aside: If you want to know what's in Optiphen, look at the INCI name. It contains Phenoxyethanol (and) Caprylyl Glycol. If another company is making Optiphen under a different brand name - we see this all the time for surfactants - the INCI name will be the same, and you can buy that instead.

To summarize: In an emulsified sugar scrub, you can't use sodium benzoate or Optiphen as they aren't broad spectrum preservatives. If your supplier doesn't know the name of what you're asking for, refer to the INCI name as that should be the same around the world.

Before I leave this topic...If you commit to learning one thing this year, learn about INCI names! It will save you gobs of money as you won't order the same thing three times from different suppliers, and save you time as you might be able to get all you want from one place. I know this isn't a particularly sexy topic, but it will save you more time, money, and sanity that you would believe possible. Check out at least the first two links below to learn more!

Related posts:
Weekend Wonderings: Learning INCI names
Learning this one weird trick will save you money...
What's an INCI name?
Substitutions: Reading INCI names
Reading INCI information
Getting to know INCI names


Admin said...

Hey susan! Speaking of hard to find ingredients could you please make a post about making a hair conditioner without btms... I have this product that I love and what they list is cetearyl alcohol and centrimonium chloride but I don't have experience with those ingredients could you make some basic recipes with those? Thank you!

Anonymous said...

So, this is one of the hottest debates going on some of the making groups. What preservative should one use in an emulsified sugar scrub (or in this case a solid scrub bar), do to its unique pH, nature, and use in wet environs with wet hands. And the answer is almost always "here's a list of preservatives - please go do your own research". I get this from a CYA perspective, and from a "make the student do their own learning" perspective. But it can be MADDENING when you think something is going to take you 5 minutes to look up, and you end up down a rabbit hole for an hour, and are still not really sure of your answers.

So...for those of you in this situation who would like for someone to cut to the chase and just give you a list of appropriate preservatives for this application to further research, I put "Solid Scrub Bar" into the search engine on this site, and this is what came up. Note that Susan has been writing this blog for a LONG time, and her own knowledge base has changed over time. Hence some of the varying information here. As we've just learned in this post, Optiphen isn't recommended. Also note that there is debate on using Phenonip or Optiphen, which are oil soluble, in a product where what needs to be preserved is the water that penetrates the product during use. Optiphen ND (more broad spectrum - use in pH below 6) is not recommended for anhydrous products. Optiphen plus? Maybe, but perhaps not good with sodium lactate (per this post Personally, I'd go with phenonip, despite the paraben freak out that tends to go with it.

In your July 2, 2014 post, you list Phenonip, Optiphen, or Liquipar Oil.
In your July 7, 2010 you don't list the need for a preservative.
In the May 19, 2013 post you mention that sodium lactate is adequate "because the liquid version will have enough preservative in it to preserve the water, plus it's bacteriostatic".
In the May 27, 2016 post, you use phenonip. Same for the May 22, 2009 post.
July 25, 2010, no preservative, on purpose.
November 14, 2009, none included, but edited note at the end to include phenonip (though this recipe does contain 3% sodium lactate).
May 24, 2009, "preservative of choice".

Susan Barclay-Nichols said...

Hi Admin. No, you can't make a conditioner that includes oils and things like cetearyl alcohol with a cationic ingredient like cetrimonium chloride as the emulsifier as it's not a great emulsifier. I've made tons of conditioners with just cetrimonium chloride - do a search on the blog - but you couldn't incorporate an oil soluble ingredient like cetearyl alcohol into it. I have a feeling that if you posted the ingredients list for the product you like, it'll have another emulsifier in there somewhere.

Hi milesawayfarm. Thanks for the summary of what I've written in the past! I have addressed this in a post on the blog - debate: water or oil soluble preservatives in an emulsified scrub - and basically I'm still on the side of using an oil soluble preservative like Phenonip in the product, especially when it contains some water soluble components. (It's an interesting discussion indeed, and the science is always changing!)

In the May 19, 2013 post, I write:

Sodium lactate really is a big part of the hardening of this bar. You can find sodium lactate crystals - find them at Lotioncrafter, for example - but how would you dissolve it? It's water soluble, so you'll have to use a bit of water anyway. And if you're adding 3% sodium lactate, you're okay without a preservative because the liquid version will have enough preservative in it to preserve the water, plus it's bacteriostatic, so less than 5% will be fine in this product.

Having said this, I use Phenonip in my bars these days, which will be enough to preserve the entire product (use it at 1% of the non-sugar or salt part of the recipe). (I'm in the process of updating my bar recipe posts with this information, but I haven't found all of them!)

In the quoted post above, I'm saying that you don't need a preservative for the water in the sodium lactate as there's preservative in the liquid version of sodium lactate. The "it's bacteriostatic" refers to the sodium lactate, not to any preservative or preserving power it might have. Sodium lactate shouldn't be used as a preservative as it isn't one.

As you can see, I go on to say "Having said this, I use Phenonip" then note that I'm updating my bar recipes to include preservatives.

As for a definitive answer, I use Phenonip and I'm happy with it. I would happily recommend others use it. If one doesn't like parabens, then they will have to do some work to figure out what else would work because there's only so much testing I can do, and I'm really happy with Phenonip! I hope this helps!

Molly Fyfe said...

Hi Susan,
If I am making a shampoo with Cationic Guar and use Citric Acid as a wetting agent, what "green" preservative would you recommend? I was using MicroGuard (Gluconolactone and Sodium Benzoate) from Herbarie and didn't realize that combining this w/ Citric Acid would result in creating a carcinogen. Yikes!!!
Molly Fyfe

Susan Barclay-Nichols said...

Hi Molly! Take a look at the preservatives section of the blog to see what preservatives will work with your recipe. Quick question: What do you mean that you're using citric acid as a "wetting agent"?

Molly Fyfe said...

Hi Susan,
I am super green at this whole thing and not formally trained at all. May I defer to you as to what is a "wetting agent"? Here is the definition I found on Google regarding this term: "a chemical that can be added to a liquid to reduce its surface tension and make it more effective in spreading over and penetrating surfaces" I realize that you are asking me to explain this but I'm sad to admit that I'm not entirely sure I can explain in my own words.
Here's my back story: I am using cationic guar gum in a shampoo but in all of my batches, the guar gum keeps falling out of solution. In an effort to try to figure this out, I read on a board (I cant remember which one, it was a awhile ago) that the reason the guar is falling out is because the recipe needs Citric Acid as a "wetting agent" for the Guar. Does this make any sense? Do you know why, even with the addition of Citric Acid, the Guar still falls out?
Molly Fyfe

Susan Barclay-Nichols said...

Hi Molly! That is what a wetting agent is - we generally called them "surfactants", and you can find them in all kinds of things - but citric acid isn't a wetting agent. It's a chelating ingredient, it's an anti-oxidant, and it can alter the pH of a product pretty dramatically. I'm going to guess you don't have a pH meter or a tiny tiny scale to measure amounts like 0.05% or 0.1% and you're adding too much, which isruining the product, hence the guar gum not staying in suspension. You could be using too much cationic guar gum, you might not be using the right type, you might be using a soap based shampoo instead of a surfactant based shampoo, and so on. There are just too many variables for me to help further without your complete recipe in percentages along with your complete process.

Having said that, as you're using a recipe that I didn't create, I'll refer you back to the person who wrote the recipe as it's a lot of work to troubleshoot a recipe that isn't mine.