Difference Between Tromethamine and Triethanolamine

Both Tromethamine (TRIS) and Triethanolamine are commonly used in cosmetic formulations primarily as pH adjusters to increase alkalinity.

• Function: Both serve the same main purpose of adjusting pH.
• Form: Tromethamine is typically a white powder, while Triethanolamine is a clear liquid.
• Alkalinity: Tromethamine generally provides more alkalinity per unit weight compared to Triethanolamine due to its chemical structure and pKa value.

Safety and Stability

Concerns about Triethanolamine often relate to potential impurities, such as nitrosamines, which can form under certain conditions. High-purity grades, like Triethanolamine 99%, are specifically tested to minimize these concerns and are generally considered safe for cosmetic use within regulatory limits.

Regarding stability, while both are used for pH adjustment, Triethanolamine can sometimes cause issues with formula clarity, particularly in gel formulations containing high levels of alcohol or ingredients sensitive to electrolytes. This might be why formulators look for alternatives in specific challenging systems.

Alternatives for Gel Formulations

If you are making a gel formula that is sensitive to electrolytes and find that Sodium Hydroxide (NaOH) does not provide the desired clarity compared to Triethanolamine, AMP (2-Amino-2-methyl-1-propanol) 95% (Deodorized) is an excellent alternative.

AMP is an alkali pH adjuster known for providing better formulation stability and helping to maintain clarity, especially in alcohol-based or electrolyte-sensitive gel systems where Triethanolamine might cause haziness. It is a suitable substitute when clarity and stability are critical.