Triethanolamine? In My Shaving Cream?

Marc writes:
“Could you write an article on the best shave soaps that do not have Triethanolamine as a component because it has been linked to cancer and is used by Talyor…and other high profile soap companies shown in articles on this site.”

What Is Triethanolamine?

First let’s see what Wikipedia says on the subject:

Triethanolamine, often abbreviated as TEA, is a viscous organic compound that is both a tertiary amine and a triol. A triol is amolecule with three alcohol groups. Triethanolamine is a strong base. Triethanolamine can also be abbreviated as TEOA, which can help to distinguish it from triethylamine.

Triethanolamine is used primarily as an emulsifier and surfactant. It is a common ingredient in formulations used for both industrial and consumer products. The triethanolamine neutralizes fatty acids, adjusts and buffers the pH, and solubilises oils and other ingredients that are not completely soluble in water. Some common products in which triethanolamine is found are liquid laundry detergents, dishwashing liquids, general cleaners, hand cleaners, polishes, metalworking fluids, paints, shaving cream and printing inks.

Allergic reactions

A 1996 study found that triethanolamine (TEA) occasionally causes contact allergy. A 2001 study found TEA in a sunscreen caused an allergic contact dermatitis. A 2007 study found TEA in ear drops caused a contact allergy. Systemic and respiratory tract (RT) toxicity was analyzed for 28 days in a nose specific inhalation 2008 study in Wistar rats; TEA seems to be less potent in regard to systemic toxicity and RT irritancy than diethanolamine (DEA). Exposure to TEA resulted in focal inflammation, starting in single male animals from 20 mg/m3 concentrations.

A 2009 study stated patch test reactions reveal a slight irritant potential instead of a true allergic response in several cases and also indicated the risk of skin sensitization to TEA seems to be very low.

Tumors

Reports indicated that TEA causes an increased incidence of tumor growth in the liver in female B6C3F1 mice, but not in male mice or in Fischer 344 rats. A 2004 study concluded “TEA may cause liver tumors in mice via a choline-depletion mode of action and that this effect is likely caused by the inhibition of choline uptake by cells.”

Environmental toxicity

A 2009 study found that TEA has potential acute, sub-chronic and chronic toxicity properties in respect to aquatic species.

Regulation

TEA is listed under Schedule 3, part B of the Chemical Weapons Convention as it can be used in the manufacture of nitrogen mustards.

OK, so triethanolamine might be toxic to fish, and used in the manufacture of nasty things.  But linked to cancer?  Let’s dig a little deeper.
The U.S. National Center for Biotechnology Information says this:

Evaluation: There is inadequate evidence in humans for the carcinogenicity of triethanolamine. There is inadequate evidence in experimental animals for the carcinogenicity of triethanolamine. Overall evaluation: Triethanolamine is not classifiable as to its carcinogenicity to humans (Group 3).

However:

The substance is irritating to the eyes, skin and respiratory tract;

and

Repeated or prolonged contact may cause skin sensitization.

How about another source? The Envinromental Working Group is described as

…a non-profit, non-partisan organization dedicated to protecting human health and the environment.  Our mission is to empower people to live healthier lives in a healthier environment. EWG drives consumer choice and civic action with its game-changing investigations and research on toxics and environmental health, food and agriculture, and water and energy. For two decades, EWG’s groundbreaking research has changed the debate over environmental health. From households to Capitol Hill, EWG’s team of scientists, policy experts, lawyers, communication experts and programmers has worked tirelessly to make sure someone is standing up for public health when government or industry won’t.

Their take on Triethanolamine?  On the one hand:

Classified as expected to be toxic or harmful and Classified as medium human health priority (per Environment Canada Domestic Substance List)

But also:

Cancer – not classifiable/not likely to be human carcinogen (per Int’l Agency for Research on Cancer–IARC).

I also found some industry groups that discuss the ingredient but don’t really offer anything new:
Truth In Aging
Cosmetics Info

The bottom line?

Triethanolamine is a very common ingredient in shaving creams.  From what I have been able to find from reliable sources, triethanolamine has some undesirable properties and, like just about any cosmetic ingredient, can cause allergic reactions, but there is no reliable information linking it to cancer.  However if you are still concerned there are a few traditional shaving creams that do not have it, including Speick and Proraso.
Physicians, scientists, and soap/cream artisans–feel free to weigh in with your comments too!