Reverse engineering: Magnesium Carbonate

[bat755]

Hi soapmakers,
I’m trying to reverse engineer the soaps from a popular brand.

The factor I want to replicate is the intensity and persistence of the fragrances. As far as I can read on the ingredients list they use EO to add scent.
In this particular soap I read: Orange EO, Cedarwood EO, Rosemary EO.

The additives used are: Kaolin, Sodium Chloride and Magnesium Carbonate.
I’ve found this ingredient from my Italian supplier and it sells with the INCI name “Magnesium Carbonate Hydroxide”.

The description from the supplier says: Magnesium carbonate is used as a filler in decorative cosmetics in free or compact powder, it helps to enhance the touch of powders and blush, its ability to absorb oil helps to compact eyeshadows, powders or blush, it is often used to incorporate perfumes in decoratives.

May be this the key to fix the scents as they do? I’ve tried to replicate the recipe adding 45g of the EO blend for 1kg of oils. The smell is good in the first 2 or 3 weeks but the citrus part is mostly gone after 6 weeks.

 

[AliOop]

What an interesting question! After a little poking around on the webs, what I found was that magnesium carbonate, or magnesium carbonate hydroxide, is used mostly for buffering and adjusting viscosity.

You could try soaking the EOs in the clay for some time to see if that helps the scent to stick. There are a few threads here on SMF about that.

 

[Kcryss]

I agree! Very interesting question. I think you're on the right track with the comment you made about it being the key to fixing scents. I wonder if this is the magic many many people on here have been searching for.
I found an article talking about the absorbent properties of magnesium carbonate. Based on this article, I wonder if maybe it does help with getting essential oils to stick in soap. I would think allowing the eo's to soak into the mc prior to adding to soap would be a good first try on experimenting.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7821260/

 

[not_ally]

I really wonder what the big companies use as scent fixatives as well. I use FOs that I know are sticky in soap, so don't struggle with the EO issue, but my shampoo bars just don't allow the scent to stick in hair. I love using them, but miss having my hair smell nice and clean for a long time after washing it, like it did with store-bought liquid shampoo.

 

[Kcryss]

I'm with you, I would love to know the secret. Wondering if the mc might get us all a little closer.

 

[AliOop]

I believe that scent fixatives, like preservatives, are often subsumed into the “fragrance” listed on the label. I can’t swear to it, but that’s my understanding - that this is allowed under the labeling rules.

It is also my understanding that some FO components that are base notes also act as fixatives, in addition to their olfactory contribution to the overall scent. Since these are often the most expensive part of the formulation, they aren’t used in such high amounts in scents available to hobbyists. If you want to pay for a custom formulation, or buy those components separately ($$$), you can achieve scents that last longer.

What I don’t know is if using a fixative, whether as part of the scent or as a separate ingredient, changes the IFRA allowance for that FO. It seems like that could be the case, to the extent it is causing the chemical components to hang around longer, thereby increasing exposure. Does anyone know if that’s the case? It is one reason I hesitate to use a separate fixative. Most products that have fixatives give me intense headaches!

 

[not_ally]

I found the below in a file about fixatives which I meant to follow up on (for the shampoo bars) and never did. I probably will try the benzoin powder and/or the AromaFix next time I place an order with WPS or LotionCrafter. The reviews for benzoin powder were surprisingly good regarding its effectiveness as a fixative.
-------------------
Benzoin powder:

https://www.wholesalesuppliesplus.com/products/benzoin-powder.aspx
2oz/$9.45
"Benzoin powder is a natural organic compound. It is commonly used as a fragrance fixative in soap by reducing the evaporation of fragrance."
Off white powder, INCI: Styrax Benzoin gum
WPS reviews are v. positive re scent retention, but a number also say it is gritty in soap, some say it discolors or creates brown specks. Reviews mention adding to oils or infusing in carrier oil.

Orris Root:

One WPS benzoin review mentions orris root as a fixative. SMF search produced this link: https://www.soapmakingforum.com/threads/orris-root-powder.4602/
Various rates suggested for use of orris with CP. Also mentions various other EOs as fixatives. ("Benzoin powder or e/o, orris root powder, frankincense e/o, patchouli e/o, oakmoss e/o, cedarwood e/o, myrrh e/o, ylang ylang e/o, vetiver e/o, copaiba balsam e/o and kaolin clay are all examples of fixatives that can be used in soapmaking.")

AromaFix, aka Glucam P-20:

https://lotioncrafter.com/products/aromafix?_pos=5&_sid=decaabe25&_ss=r
INCI: PPG-20 Methyl Glucose Ether

"[A] unique water-soluble oil with a broad range of miscibility in water, alcohol and most organic oils and solvents (except hydrocarbons). AromaFix™ has a distinct emollient feel and a high film gloss. It serves as a perfume fixative, anchoring top notes typical of florals, herbals, citruses and lavenders. It shows the least effect when added to oriental, heavy woodsy and other base notes."

"In fragrance containing formulations, it acts as a fixative by subduing volatilization of the "high notes" ... It is one of the few naturally-derived cosmetic fluids that are miscible with water, alcohols, organic esters, and oils."

 

[Savage Daughter]

I found the below in a file about fixatives which I meant to follow up on (for the shampoo bars) and never did. I probably will try the benzoin powder and/or the AromaFix next time I place an order with WPS or LotionCrafter. The reviews for benzoin powder were surprisingly good regarding its effectiveness as a fixative.

I am awaiting my litre bottle of this & looking forward to playing with it! Not the powder, however. Got some tonka beans on the way too! WOOT! and a couple KG of vanilla beans. I am guessing both could work quite nicely as scent fixatives, used in various ways.

I am very curious about the magnesium though, because I know magnesium in various forms is super effective, and in many ways! Will definitely be doing more research on this!

Orris Root:

One WPS benzoin review mentions orris root as a fixative. SMF search produced this link: https://www.soapmakingforum.com/threads/orris-root-powder.4602/
Various rates suggested for use of orris with CP.

I used orris root when I first started making soap in the 90s. It definitely worked, although I don't know how it would compare to what I do now, using my essential oil slurry, soaking botanicals overnight at least with essential oils, using salt, the way I store my soap, and so on.

Also mentions various other EOs as fixatives. ("Benzoin powder or e/o, orris root powder, frankincense e/o, patchouli e/o, oakmoss e/o, cedarwood e/o, myrrh e/o, ylang ylang e/o, vetiver e/o, copaiba balsam e/o and kaolin clay are all examples of fixatives that can be used in soapmaking.")

I use all of the above in addition to my slurry & soaked botanicals when I am creating blends which I want to have really stick around well

AromaFix, aka Glucam P-20:

https://lotioncrafter.com/products/aromafix?_pos=5&_sid=decaabe25&_ss=r
INCI: PPG-20 Methyl Glucose Ether

"[A] unique water-soluble oil with a broad range of miscibility in water, alcohol and most organic oils and solvents (except hydrocarbons). AromaFix™ has a distinct emollient feel and a high film gloss. It serves as a perfume fixative, anchoring top notes typical of florals, herbals, citruses and lavenders. It shows the least effect when added to oriental, heavy woodsy and other base notes."

"In fragrance containing formulations, it acts as a fixative by subduing volatilization of the "high notes" ... It is one of the few naturally-derived cosmetic fluids that are miscible with water, alcohols, organic esters, and oils."

Personally, I wouldn't touch this with somebody else's 10 foot....pole LOL

 

[not_ally]

I am awaiting my litre bottle of this & looking forward to playing with it! Not the powder, however.

I think I had read that benzoin was kind of a PITA to use in resin form (although I keep meaning to order it because it is supposed to smell so nice) and thought the powder would be easier to use as a fixative. Let us know how it works!

 

[Savage Daughter]

I think I had read that benzoin was kind of a PITA to use in resin form (although I keep meaning to order it because it is supposed to smell so nice) and thought the powder would be easier to use as a fixative. Let us know how it works!

That's what I see so many people say about pine tar too, yet I had no issues with any of it. Weighing, adding to my soap, batter getting too thick, cleanup etc. Zero problems. Other people's experiences which I keep seeing everywhere had me on the fence about how large of a batch I wanted to try out first, to be honest, despite the fact that I know other people's experiences are never what I should use to gauge a situation. Read, absorb known facts (which are up for debate), then forge ahead blazing my own path

I think it depends on the person & their ability to think their way around perceived 'problems' vs seeing things as challenges which are very much workable, or even what motivates them.

Me & benzoin are gonna have a blast together, just like me & pine tar & goats milk & the tree resin I am still working on cleaning LOL