Sunday, January 29, 2012

When should you use a preservative?

I'm getting a lot comments and e-mail from newbies lately - welcome! - asking about preservatives. The answer is - whenever you have a product that contains water or might be exposed to water, you must add a preservative.

If you want to make an oil in water lotion (what we normally make), you must add a preservative. If you change every millilitre of water in the lotion to being honey or aloe or a hydrosol, those are still water based ingredients and you must add a preservative. If you make a body wash, shampoo, conditioner, or any other product that contains water or a water like ingredient, you must add a preservative.

If you have a product into which someone might put their wet hands - for instance, a sugar scrub - you will need to add a suitable preservative. (Click here for more information on water activity and preserving!)

Let's go back a step...What is a preservative? Preservatives help prevent microbial growth in our products, which can cause separation of our emulsions, speed up rancidity of our oils and butters, and cause weird smells and colours.

Vitamin E is NOT a preservative. It is an anti-oxidant that can help retard rancidity, but it is not a preservative that will prevent microbial growth.
Citric acid is NOT a preservative. It can be used as an anti-oxidant that can help retard rancidity, but it will also mess with the pH of your product (making it more acidic by 1 pH at 0.2% or so).
Grapefruit seed extract is NOT a preservative. (I've gone into greater detail about this in this post.)
Essential oils are NOT preservatives. They might have some anti-microbial features (like eugenol), but none of them have been proven to be effective preservatives in our products. (More about this tomorrow!)

It really doesn't matter why you can't use a preservative - if you make a water containing product, you must use a preservative. Offering up what seems like a good reason to leave out the preservative doesn't mean it's okay to leave it out. Fungus, bacteria, and yeast don't care if you're allergic or sensitive, if you're vegan or you want the product to be organic - they'll still grow in your lotions, and make you and the people you love sick. Everybody's got their something: I'm lactose intolerant. Lactaid Ultra pills don't help, and I've even gone as far as taking two before eating Raymond's amazing homemade ice cream and I still get sick. It sucks, but that's my reality. I don't get to eat ice cream or drink egg nog or enjoy cake with tons of whipped cream. In a similar vein, if you are allergic to preservatives, if you want only 100% organic products, if you're against them somehow, or if you don't want to spend money on more ingredients, then you don't get to use water containing products and will have to stick to anhydrous products.

I know this sounds harsh, but this is the reality. I don't care how many blogs or suppliers out there try to convince you that you can make products that don't contain preservatives, you can't make a water containing product without a preservative, and writing to me to ask for my blessing to make a water containing product without a preservative is pointless. It's like asking your vegan friend to grill you up a tasty steak - it's not going to happen.

Related posts:
Preservatives - a whole bunch of posts on the topic
Why use a preservative?
Mechanisms of rancidity
Storing products in the fridge
If you really want to make products without preservatives...
The importance of preservatives

38 comments:

Kathy said...

Susan - I just started making liquid soap, and the formulators and blogs all state that the resulting pH in liquid soap is around 9.5-10 so you don't need to add a preservative? Correct or no?

PS - I'm really hoping that someday you do a series on liquid or cream soap making. Thanks.

Susan Barclay-Nichols said...

Hi Kathy! I'm not talking about soap (as defined as being a product that is saponified by adding lye to oils and creating soap...not syndet bars!) when it comes to preservatives. Just the things that have a pH of 8 or lower.

Which doesn't mean that one can raise the pH of your body wash, shampoo, and so on to 8 to avoid using preservatives!

TygerMae said...

I would still use preservatives in liquid soap. I've read too many articles about contaminated liquid soap and definitely preserve cream soap, it has enough free oils in the mix to cause really interesting things to grow. Ask me how I know. Ick.

Susan Barclay-Nichols said...

Hi Tyger Mae! How do you use preservatives in liquid soap? Which ones do you recommend? (Remember that I know absolutely nothing about soap making!) I really need to learn more about this topic!

vivi said...

Thank you for reminding people to use preservatives-it's for the their health and safety! Far worse to have green lotion, or giving a contaminated gift to a friend!

Shahn said...

Hi

I am attepting to make a herbal hair oil for myself. One item I would like to include is Hibiscus Extract: INCI: Glycerin (and) Water (and) Hibiscus Sabdariffa Flower Extract.The extract contains the preservative potassium sorbate, and sodium Benzoate. Since it contain preservatives should I add another preservation because of the water?

Susan Barclay-Nichols said...

Hi Shahn. What is in the hair oil? Is it all oil except for this hibiscus extract? If so, how do you plan to emulsify the water soluble hibiscus extract into the oil? I don't think you will find a way to include this product into an anhydrous product without a lot of work. I'd have to see that recipe to offer more advice.

If you are making an emulsified product, you will have to add a preservative to the entire product. There isn't enough preservative in the extract to preserve your entire product. Just add it to your cool down phase - which is where we generally add extracts - and add the preservative with it.

TygerMae said...

How I usually add preservatives to my liquid and cream soaps is I wait until the very end after it is diluted and cooled down. I like to use the maximum rates as I don't know how it will be used in the end. It is such a small amount compared to the product I feel it isn't as much a problem as it would be if some nasty started growing. I have been using Liquid Germall Plus. I had been using Optiphen, but I found I didn't like the reaction with my skin. I've found you have to be careful which preservative you use for liquid and cream soap as some will work great but others just fail. It helps to do research and know the ph of the resulting soap.

Shahn said...

Hi

Here are my ingredients: powdered aloe, hibiscus,hawthorn herb,fenugreek, herb, garlic oil, blackseed oil, horsetail herb,sulfur, and macademia oil.

Thanks

Tina said...

Hi there,
If I make a face mask/ scrub with ground almonds, oats, lavender flowers, and honey (no water in sight), do i need a preservative? If I don't use one, how long would you estimate it would be good for both in and out of the refrigerator? (I realize you can only give a big estimate). If you were to add a preservative, which would you recommend and how long would that extend the shelf life if not refrigerated?
Thanks so much for your blog!
Tina

Luisa Perry said...

Hi Susan!
I just found this post of yours. I am wondering if aloe butter - aloe and coconut oil - would be water or oil? I was wondering about adding it to my body butters, but now I'm not sure if that would require a preservative. The jar says it has a one year shelf life, but lists no ingreduents other than aloe and coconut oil.
Thanks!
Luisa

Susan Barclay-Nichols said...

Hi Tina and Luisa! I've answered your questions in today's Weekend Wonderings. The short answers are you really can't preserve that face mask and no, you don't need to preserve that ingredient in an anhydrous product as it probably contains a preservative already.

Vanessa Thibodeaux said...

Hi there,
I just opened up a small all natural body business. I made a sweet orange body butter using shea butter, and some other ingredients. A month later it was moldy. It was in a clear container and I think it melted in the car by accident. Do you think this is why or should I be using a preservative in my body butter's? Thanks

Vanessa Thibodeaux said...

Hi there,
I own a small natural body business. I made a sweet orange body butter and a month later it was moldy. Should I be using a preservative and what do you recommend? I use shea butter but have now switched to mango butter with almond oil it seems to be a better combination for my customers. Thanks

Anonymous said...

Hi Kathy. I'm new at making lotions, etc. Although I want organic as possible I fully understand the (must have) necessity of having a preservative. I just don't know how to know how much to put in. I don't know how to measure or calculate this so I know it is a sufficient amount. All the articles I've read on the net seem to give strange percentages and/or ratios that I am unable to measure. It seems you need a scientific calculator and a lab to do the work.

What do you suggest? btw...what brand, type of preservative do you like?

btw...if I am making a lotion with aloe vera gel (which already has a preservative (diazolidinyl urea) in it would that work? then again, I am guessing that the manufacturer put enough in for the entire bottle of aloe vera gel so that if I only use 1/4 cup in my 13oz bottle of shampoo or lotion bottle (plus the preservative used in castile soap...if making a shampoo) then it is not enough for my lotion or shampoo...would that be a correct assumption??

Thanks so much~!

Susan Barclay-Nichols said...

Hi Anonymous. Who is Kathy? Are you referring to the first comment in this section? I'm Swift or Susan, the author of this blog...

Have you checked out the preservatives section of the blog? There's lots of information on preservatives there and information on how much to use of each one. If you look at the blog, you'll see my favourite is liquid Germall Plus as it offers great protection for the greatest number of products.

You have to preserve lotions and shampoos, so there isn't enough preservative to preserve an entire product by adding the aloe vera gel. Or are you adding this aloe vera to a previously made product? If you are, don't. We don't add things to previously made products. Are you using castille soap as a shampoo? That's not a great idea as it is the wrong pH and can cause a lot of damage to your hair. (Click here for that post.

Megan Xi said...

Hi Susan, I just enquired about purchasing 100% castile soap paste on brambleberry. I asked whether I would need a preservative once I dissolved the soap paste in water and they told me its not necessary as the PH level of the liquid soap should kill any bacteria.. true?

Susan Barclay-Nichols said...

Hi Megan. I've just written up the answer to your question in today's post. The short answer is that I would use a preservative in the product as the final pH is likely to be in the barely alkaline range. The long answer is in the post! Great question!

Anonymous said...

hi Susan , I'm in the process of making an organic shampoo and conditioner and iv heard that trace minerals can b used as a natural preservative, but I'm struggling to find more info on it, what do u think?
thanks heaps

Susan Barclay-Nichols said...

Sorry, Anonymous, but I have no idea what trace minerals are. Can you link me to a few sites that might give more information? I wouldn't trust anything if I haven't seen study results, so I suggest you look for those for evidence that it might be effective.

Anonymous said...

How about for a laundry butter recipe that used grated soap, washing soda, distilled water, and borax? I've heard some say that microbes couldn't survive in this, but the head space between the lid and jar would be of concern to me. And doesn't it depend on how much water is used too? I feel like this would need preservative.

Taren Watt said...

I am trYing to make a lip stain with avacado oil, dried herbs and roots, mango butter and non nano zinc oxide, vegetable glycerin, jobaba oil and bees wax. I still want to protect my product for shelf life. What kind of preservative can I use to make the safest natural or organic product?

Susan Barclay-Nichols said...

Hi Taren! You don't need a preservative if you aren't using water. Glycerin is water soluble, so you won't be able to incorporate it into this recipe without an emulsifier of some sort. If you do that, then you'll need a preservative as you'll have water in the recipe. I don't know what to suggest for a mostly oil soluble product that needs to be lip safe. Take a trip to the preservatives section of the blog to compare a few that might work for you.

Anonymous said...

I am starting a business. And I will be selling lip scrub and lip balm. Will I need to add a preservative to them? And if I do need to add a preservative, what preservative should I add?

Susan Barclay-Nichols said...

Hi Anonymous. Please read the post to find out more about when to add preservatives. Can I ask you a question? Are you ready to sell products when you don't know everything about your ingredients and products?

Shannon said...

Germazide PSB vs E Preservative? I cannot source Germazide PSB and that is the preservative I used for my patented product already challenge tested. I came across your blog (love) and thought you may have an educated opinion on this matter. Thank you!

Susan Barclay-Nichols said...

Hi Shannon. I don't know either of those preservatives, so I can't comment. (I couldn't find E preservative in Google. Does it have another name?)

Blair said...

Hi Susan! :) Is a product with these ingredients well preserved: Purified Water, Decyl Polyglucose, Organic Vegetable Glycerin, Organic Apple Cider Vinegar, Xanthan Gum

Thx!

Susan Barclay-Nichols said...

Hi Blair! No. This is just asking for contamination if you don't use a good broad spectrum preservative!!

jesslla said...

I make laundry butter which uses coconut oil soap (made by me), water, borax, and washing soda.

I assume it needs a preservative, because of the water? How do I figure out how much to use? I have Germaben and they said to use between .3% and 1% of the total weight of the recipe. Help?!

Thanks, Marlene

Susan Barclay-Nichols said...

Hi Jesslla! You would determine your preservative based on the weight of the product. If you have 100 grams, you'd use 0.3 grams to 1 gram. And so on!

I'm glad to see you want to use preservatives! Awesome!

Steve said...

Hi there,

What a great wealth of information here :)

I have a product which has 40% water, 15% Glycerine, 15% IPA and the balance is oxide pigments. A very similar product contains no preservative, or at least it's not listed on the label or MSDS? They give a 12M POA and 10 year unopened self life? They talk about UV sterilization? I am about to submit this product to the chemist and not sure if I should add a preservative and which one!! Hope you can help!

Thanks Steve

Susan Barclay-Nichols said...

Hi Steve. I have no idea what IPA might be, and I can't Google it as the results are full of beer! Could it be isopropyl alcohol?

I have a feeling that the argument would be that 15% glycerin or 15% isopropyl alcohol may be enough to preserve the product? I wouldn't trust it either way. If it contains water, I add a preservative, regardless of the other ingredients.

As an aside, is this 30% oxide pigments? What kind of product is this?

Nuban Beauty said...

Dear Susan I just made a body wash containing aloe vera,essential oils,citric acid,licorice extract,tumeric and cinnamon. Am an amateur at this and I didn't add preservative and now coming across your article am scared what do I do incase there is contamination already going on

Nuban Beauty said...

I made the body wash 2day ago

Susan Barclay-Nichols said...

Hi Nuban! It's hard to answer this question without knowing all the ingredients, but if you're making a surfactant based product with all those botanical ingredients and no preservatives, then I'd say yes, you are probably seeing the start of contamination. There's nothing you can do but throw it out.

As a question, why are you adding citric acid? Do you have a pH meter to check the final result?

Tonya said...

Hi Susan,

I have a body butter made with shea butter and aloe vera. I assumed that aloe vera can be considered a water-based product so I have a preservative in it. Since my mixture is anhydrous except for the aloe vera which already has a preservative - do I need to still add one?

My test batch is made with Lily of the Desert brand aloe vera which has potassium sorbate for mold. It still says to refrigerate after opening.

Susan Barclay-Nichols said...

Hi Tonya. Yes, whenever you use anything that contains water, you have to use a preservative. There are no exceptions to this rule.

Potassium sorbate isn't a broad spectrum preservative, so I suggest you get a water soluble one into that bottle of aloe. I had that aloe vera once, and it was contaminated within a few weeks.

So there's not a good preservative in the aloe vera in the first place. And there's only enough preservative for the aloe vera, not for the entire product. So you have to add a preservative to the product to preserve the whole product.

As I've already written about these topics at length before, please check out these posts for more information...
From the newbie section: What you need to know about making any product

Are the preservatives in our ingredients enough to preserve a product?