Triethanolamine and nitrosamines

Avick · December 2014

Has anyone done any digging into the relationship between triethanolamine and nitrosamines and/or general safety of TEA that they would be willing to share or link me to?

Other than neutralizing carbomers, I'm currently using this to adjust the pH of a fairly strong plant extract for inclusion in an emulsion at fairly high levels and am in need of something stabilizing. Client is concerned b/c of skindeep website ranking, but I'm not finding their links all that helpful to my understanding of the actual risks.

Thanks so much in advance!

MarkBroussard · December 2014

Do you have Carbomer included as part of this formulation? Or, are you merely trying to adjust the pH with TEA?

Avick · December 2014

Well, both.

I have one formula w/ a carbomer and another where I'm just using it to adjust pH and stabilize. I have had a colleague suggest AMP (aminomethyl propanol) as an alternative...

I don't know much about the make-up of the low-pH botanical, so I am a little wary b/c I don't want to create some weird derivative, but I need some way to adjust the pH and I think buffering it will create too much electrolyte load.

MarkBroussard · December 2014

If you are only trying to raise the pH, you might consider Sodium Lactate.

I used to know a really neat technique to gel carbomer and raise pH using an all natural ingredient, thus eliminating the use of TEA. I'll have to go through my notes to refresh my memory, but there are better alternatives than TEA.

MarkBroussard · December 2014

Also, have you considered using gelling agents other than carbomer? By "stabilizing" ... I assume you're referring to stabilizing your emulsion? What emulsifiers are you using?

MarkBroussard · December 2014

Avick · December 2014

Wow, thanks for the great information, Mark.

Yes, by stabilizing, I mean stabilizing the emulsion. I'm using this same low-pH botanical in several products.

The emulsions use lucas-meyer phospholipid emulsifiers: amisol soft, lecigel, heliofeel.

The other two are serums, one using a carbomer (Carbopol Ultrez 10) and one using HE cellulose.

MarkBroussard · December 2014

In that case, take a look at Lucas-Meyer ECOGEL ... mixture of Sclerotium Gum, Pullulan, Xanthan and Lysolecitihin.

You can also take a look at Konjac Root Powder. Much, much easier than using Carbomer, imho, if you require a crystal clear gel.

Now, if I could only remember that damned trick I used with Carbomer! But, once I started using non-carbomer gelling agents, I dropped carbomer altogether.

Good Luck!

Avick · December 2014

Wow, great! Would you recommend a particular supplier for either the sodium lactate or the konjac root? Both are very interesting, and I appreciate so much your sharing this information. ^:)^

And ah, you're right--EcoGel does look like it should have higher electrolyte tolerance! Just when I thought I had the formulas finalized... what changing one ingredient can do.

:-<

Bill_Toge · December 2014

https://chemistscorner.com/cosmeticsciencetalk/discussion/comment/3340#Comment_3340

the only amines that can form stable N-nitrosamines are secondary amines, and even then they can only form them if there's a source of nitrosonium ions present (sodium nitrite, or bronopol)

nitrosamines formed from primary amines will dehydrate to form diazonium ions, while tertiary amines (e.g. TEA) can't form them in the first place as there are no free coordination sites

if you want a reaction mechanism, look up "diazotisation of amines"

MarkBroussard · December 2014

Sure, www.kinetiktech.com for Konjac. They may also have sodium lactate. If not, for small quantities go to ingredientstodiefor.com

Since you seem quite concerned about electrolytes, are you adding a chelating agent? If so, you might want to take a look at Dissolvine from AkzoNobel with a touch of citric acid. I'm just starting to use it, but it seems to have an excellent profile.

lewhitak · December 2014

To MarkBroussard:

I also use Konjac and love it, but I do get a cloudy effect when adding a preservative to the system. May I ask which preservative you use when you do clear gels with Konjac? I have no issues with the paraben system, but if a customer wants paraben-free then I am out of luck.

Thanks in advance!

nasrins · December 2014

nitrosation of ethanolamines is autonomic?

MarkBroussard · December 2014

@lewhitak:

I generally use the following preservation system:

(1) Gluconolactone/Sodium Benzoate (1.25%)

(2) Trisodium Ethylenediamine Disuccinate (0.3%)(chelating agent) + Citric Acid (0.2%)(Preservative Booster)

(3) 1,3-Propanediol 3.0% (Preservative Booster)

Add all of the above to your water phase right up front under high shear, then heat to 77C and hold for 20 minutes. That generally ensures the Gluconolactone/sodium benzoate stays in solution.

Based on some research that I came across recently, I am going to swap the Trisodium Ethylene ... and replace it with Dissolvine GL-47-S (Tetrasodium Glutamate Diacetate) ... the studies showed a significant enhancement in preservative efficacy using Dissolvine + Citric Acid.

Also, Zemea has a nice study showing enhancement of Gluconolactone/Sodium Benzoate with 2% to 6% 1,3-Propanediol.

If I'm making a cream, lotion, etc. where crystal clear is not an objective, I also add in Caprylyl Glycol/EHG.

Hope that helps.

David · December 2014

TEA won't harm your skin, probably not even trace amounts of nitrosamines, however it is risky and above 50ppb is forbidden in Europe. So my advice is - avoid TEA if possible. It is true that you need DEA to form nitrosamines but TEA always comes with trace amounts of DEA (no matter how pure).

Bill_Toge · December 2014

@David, cosmetic grades of TEA are manufactured with the restrictions of in mind; as long as the spec meets the legal requirements, and individual batches conform to the spec, there should be no issue in using TEA

MarkBroussard · December 2014

Final Report on the Safety Assessment of

Triethanolamine, Diethanolamine, and

Monoethanolamine

(Journal of International Toxicology)

"The Panel concludes that TEA, DEA, and MEA are safe for use in cosmetic formulations designed for discontinuous, brief use followed by thorough rinsing from the surface of the skin. In products intended for prolonged contact with the skin, the concentration of ethanolamines should not exceed 5%. MEA should be used only in rinse-off products. TEA and DEA should not be used in products containing N-nitrosating agents."

It really comes down to a consurmer perception issue. But, why use TEA when you can use Sodium Lactate which is great skin moisturizing properties in addition to functioning as a pH adjuster and avoid any consumer concern about TEA altogether?

David · December 2014

@Bill That is true, but I think that is no guarantee against nitrosamines, if you have N-nitrosating agents in your formula / production.

WalterBliss · June 2021

Most polymers used for thickening are polar with many OH groups. Cationics = positive of course. They organize the water around themselves. Adding salt or ions disrupts the organization and reduces lotion viscosity. This is what makes Tiethanolamine desirable. It is inexpensive and behaves itself. Alternatives such as Angus Chemical Company AMP-Ultra PC 2000 are prohibitively expensive. Na lactate introduces sodium ions. You end up paying for it in cost with increased amounts of expensive thickener. Cost is key.

Triethanolamine and nitrosamines

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