Saturday, August 31, 2013

Weekend Wonderings: It's all about the polysorbates, baby!

There were a few questions about polysorbate 20 this week, so let's take a look at those comments!

In this post, Polysorbate 20 vs. polysorbate 80, Sam F asks, Do you think heating will aide an o/w emulsion when adding 0.3% eo's & 1.2% polysorbate 20 to water?

The short answer is yes, emulsions generally like heat. The long answer is...yes, but you have to put the things that can handle heat in a heated water phase and the things that can't handle heat into the cool down phase.

Related post: How do you know when to add an ingredient? 

Most solutions - solutes dissolved in solvents or things dissolved or mixed into water - do better when heated, and emulsions are no exception. A good emulsion generally requires three things - a chemical emulsifier (like Polawax, e-wax, polysorbate 20, and so on), general agitation, and heat.

To create your recipe, ask yourself if all the ingredients are okay with being heated. Polysorbate 20 and water will be heated, whereas the essential oils and preservative probably shouldn't, depending upon the preservative. My recipe would look something like this....

water to make up 100%

0.5% liquid Germall plus
0.3% essential oils
1.2% polysorbate 20

Heat my water to 70˚C. No need to heat and hold it as I'm using distilled water, but I do want to get it up to temperature. Let it cool to 45˚C. (Or just heat it to 45˚C, but I generally don't remember to check the water, so I tend to boil it up, then let it cool.) In the meantime, mix the essential oils, polysorbate 20, and liquid Germall Plus (or water of choice) together and add when the water cools below 45˚C. Mix mix mix, and we're done!

In this post, Ronnie A asks, Is PEG-20 (Polysorbate 20) the best emulsifier to use for a oil and water hair mist? What percentage of Polysorbate 20 would i need to use if my formulation is approximately 20-25% oil and 70% water/Rosemary Floral Water and aloe vera juice.

Quick aside before we start: I've only seen polysorbate 20 referred to as PEG-20 in one place, and it's this Wikipedia site. (And as a note, there's a lot of information there that isn't necessarily accurate.) As I mention in this post, you might find them as "tween 20" or "tween 80", which means they're derived this way, or "span 20" or "span 80", which means they're esters of non-PEG-ylated sorbitan esterified with fatty acids. I recommend calling it polysorbate 20 because no one is going to know what you mean if you call it PEG-20.

Now to the question - Polysorbate 20 isn't a good choice for a hair care product. I have three reasons for saying this...

1. It won't emulsify 20 to 25% oil. Polysorbate 20 is meant to emulsify things like essential oils in small amounts, like 2% to 3%. Polysorbate 80 might be a better choice as it is intended for carrier oils, but not more than a few percent. For 20 to 25%, you need a proper emulsifier, like Polawax or Incroquat BTMS-50 or Ritamulse SCG and so on.

At 20% to 25% oils, you're on par with a full on lotion, so you need to use a good amount of a proper emulsifier. 

2. Polysorbate 20 is a non-ionic emulsifier, meaning it has a neutral electrical charge. When you're making a hair care product, you want to use a cationic or positively charged emulsifier like Rita BTMS-225 or Incroquat BTMS-50.

Related post: Anionic, cationic, and non-ionic?

3. Polysorbate 20 is a sticky ingredient, and using more than 3% or so - depending upon your personal preference - can lead to serious stickiness in the hair.

I wouldn't use that much aloe vera in any product as it can get sticky. Try using 10% aloe vera, 10% floral water, and the rest water. Water isn't a filler - it has many uses, and you don't want tons of sticky things in your hair! And this isn't going to work as a mist. This will be a medium weight lotion, like this 70% water recipe. You will not be able to spray this product. You'll be able to pump it, though.

For a hair mist, consider using something like 1% to 5% oils, 1% to 3% BTMS-50 or Rita BTMS-225, 10% aloe vera, 10% hydrosol, 0.5% to 1.5% preservative.

Is this your first recipe? If so, please consider using a tried and true recipe that we know works - like this leave in conditioner - or find one in the hair care section of the blog?

As a quick note, polysorbate 20 and polysorbate 80 are technically solubilizer not emulsifiers. Want to learn more? Click here for a post on solubilizers vs. emulsifiers.

Related posts:
Chemistry Thursday: Why oil and water don't mix! 
Chemistry Friday: Why do we care about mixing and solubility?
Solubility of our powdered ingredients


robyn m said...

Hi. Question, would it be ok to use an oil with a short life span (grape seed oil) if i'm going to use it in a lotion with a preservative (optiphen plus)?

Susan Barclay-Nichols said...

Hi Robyn! You can use any oil you wish, but something with a short shelf life, like grapseed, will have a short shelf life. I wouldn't go for more than three months with grapeseed. And preservatives won't help the shelf life of an oil: You need an anti-oxidant to extend a shelf life.

Check out this post on preservatives vs. anti-oxidants (found in the newbies section of the blog) for more information.

Anonymous said...

I have not figured out how to contact you directly, but Halloween is coming up. There are lots of recipes going around for slime, and my son would like such a recipe...How can I safely make and preserve some neon green slime?
Thanks in advance!

Clare said...

Oh no, I've been using polysorbate 20 in my hair! I read about people oiling their long hair but I figured it would be easier to distribute the oil evenly with a spray. So I made up an oil/water spray with 5% oil, 5% polysorbate 20, 1% preservative and the rest water. Could the non-ionic-ness be damaging my hair? Wouldn't BTMS thicken the spray too much? I want my spray to be a fine mist.

Clare said...

Also, I'm quite reluctant to go to the trouble of buying and using BTMS because I have a leave-in conditioner cream where the conditioning ingredient is BTMS and it leaves my hair feeling AWFUL. Like, horrendously brittle and I can barely get a brush through it.

My hair is fine with cetrimonium chloride but I'm confused now because in one post you say it's not strong enough to have more than 2-3% oil, but here you have 2% oil plus 4% glycerine - since glycerine is not water soluble doesn't the cetac have to emulsify 6%?

Susan Barclay-Nichols said...

Hi Karen. There are loads of recipes for slime out there, but I can post the one I use for my groups. I'll do that shortly!

Hi Clare. I think it's easier to spray oil through a good mister than it is to spray oil with polysorbate 20. Try it and you'll see what I mean as polysorbate 20 is really sticky and thicker than oil! The non-ionic-ness isn't ruining your hair; it's just not offering anything to it. I use a leave in conditioner that has 2% BTMS-50 and 1% Incroquat CR and it sprays just fine. (Check out the hair care section for those recipes.)

In the recipe you reference, I use cetrimonium bromide, which is a good emulsifier, and cetrimonium chloride, which is an okay emulsifier. So there are two decent emulsifiers for a bit of oil. (Check out the ingredient list to the right hand side of the blog for those ingredients or visit the hair care section of the blog.)

Glycerin is most definitely not oil soluble. It's almost the epitome of extra water soluble! Check out this post - I addressed this question the other day.

How much BTMS-50 are you leaving in the leave in conditioner? I've never heard of BTMS making hair feel crunchy. I've seen it make hair feel greasy or slimy or something else oily, but never crunchy. How much are you including? What else is in the product? (My first instinct is that there's glycerin or propylene glycol or too much aloe vera or something like that...)

I really suggest you take a look through the hair care section and see all the recipes I've written and check out the ingredients we use. It seems like you want to make hair care products, and that would be where I would start!

Clare said...

Thanks Susan, I'm glad the polysorbate 20 isn't bad for my hair.

Oops I didn't notice that one was bromide and one chloride, sorry. The bromide one sounds better but I can only see chloride for sale here (UK).

The leave-in conditioner was one I purchased, there doesn't seem to be any humectants in the ingredients. Just water, BTMS, some oils, a thickener, citric acid, poly 60 and preservative, in that order.

I will continue reading and learning :)

Susan Barclay-Nichols said...

Hi Karen. You can e-mail me from the link on the upper right hand part of the page. And I've answered your question in today's Weekend Wonderings with a few links. I can't touch slime. It's too slimy!

Susanna Originals said...

Hi Susan,
This post answered my questions about whether Polysorbate 20 should be in the heating or the cool-down phase, but I still need a little help. I made a bug oil which works really well on both me and my dogs. 49/49% of neem oil and kiranj oil with 1% each of eucalyptus and lemongrass EOs. The oiliness of it makes it stay longer on the skin and has a bonus benefit of making your skin really soft! Its downside is that it is a brownish oil and would probably stain clothes.
A friend has a horse with sensitive skin and the poor thing has been working herself into a lather because the mosquitoes are so bad this year. She wants to try my bug-off on the mare but because of the area to be covered and the expense of the carrier oils, I figured I'd have to add water. And because I'm adding water, I need a solubilizer. I only have Poly 20 and know I need 80 because I'm using carrier oils. Can I add a little Polawax to help emulsify? I want it to remain liquid, in order to wipe on or spray. Or do you have a better idea than the water? This is a favour and a freebie, so I don't want to order anything extra and I'm hoping the Polysorbate 20 will give enough of an emulsification that shaking before use will reblend. Sorry for the long post and the probably dumb question. We're living in the mosquito capital of the maritimes and as a mosquito magnet yourself, you should appreciate how happy I am to find a Deet-less alternative that really works.

Susan Barclay-Nichols said...

Hi Susanna! If you're going to use Polawax, you might as well just make a lotion of it! Have you considered using an inexpensive carrier oil like soy bean oil? If not, then you could use water and polysorbate 80 (and make sure you use preservative!) and solubilize the oils. I don't think the polysorbate 20 will do the trick for the heavier oils.

And it's not a dumb question!

Susanna Originals said...

The only reason I'm using the neem and karanj is because they're both insecticides and seem to really repel the mosquitoes here in the mosquito capital of Canada. I'll just tell her it's not feasible unless she wants to spring for full litres of both oils. Thanks for getting back so quickly!