Diethanolamine

What is Diethanolamine?

Diethanolamine, or DEA, is a synthetic organic compound classified as an amino alcohol with the formula (HOCH₂CH₂)₂NH. Produced from ethylene oxide and ammonia, this clear, viscous liquid serves as a pH adjuster and buffering agent in cosmetic products such as shampoos, soaps, and lotions. It functions by donating or accepting protons to shift and stabilize pH levels, which supports the activity of active ingredients, boosts preservative function, and ensures a comfortable application feel. In formulations, DEA also contributes to emulsification when combined with fatty acids, helping create smooth, stable emulsions. Its alkaline properties require precise dosing to prevent shifts that could affect texture or safety. Widely used in rinse-off cleansers, it maintains pH balance over time, preventing degradation from environmental factors.

Comedogenic Rating 0/5 Low risk of clogging pores
EWG Safety Rating 10 View on EWG →

Roles in Formulation

This ingredient serves the following purposes in cosmetic formulations:

PH adjuster
Raises or lowers pH to the target range, supporting ingredient performance, preservative efficacy, stability, and user comfort.
Buffering agent
Maintains the pH stability of a formulation.

Benefits

Maintains optimal pH for ingredient efficacy and stability

Supports preservative performance in formulations

Promotes comfortable pH for skin contact during use

Who It's For

A quick guide for who this ingredient may suit (and who should be cautious).

Who May Benefit Who Should Avoid
Users of pH-dependent cleansing products like shampoos
People with sensitive or reactive skin
Individuals seeking stable, long-lasting formulations
Those wary of high-hazard rated ingredients
Those with normal skin tolerance for functional aids
Individuals avoiding potential irritants or byproducts

Safety Notes

  • High concern rating linked to possible nitrosamine formation
  • Formulate carefully to minimize irritation risks

Frequently Asked Questions about Diethanolamine

What does diethanolamine do in cosmetics?

Acts as a pH adjuster and buffering agent to stabilize formulations and support performance.

Is diethanolamine irritating?

Potential for irritation exists, especially at higher levels; rated medium based on studies.

Why the high safety concern for diethanolamine?

Primarily due to risk of forming nitrosamines under specific conditions.