What Is Diethanolamine Bisulfate?
Diethanolamine Bisulfate, also known by its chemical name Bis(2-hydroxyethyl)ammonium hydrogen sulphate, is a salt formed from diethanolamine and sulfuric acid. At room temperature it appears as a clear to pale yellow liquid that dissolves easily in water thanks to its two hydroxy (-OH) groups. The ingredient first gained attention in the 1970s when formulators were looking for safer, more stable ways to control the pH of water-based cosmetics. By turning diethanolamine into a bisulfate salt, chemists reduced its volatility and created a reliable buffering agent that helps keep skin-care formulas within a skin-friendly pH range.
Manufacturing is straightforward: diethanolamine is slowly added to diluted sulfuric acid under controlled cooling. The mixture is stirred until the reaction is complete then filtered and standardized for purity. The resulting solution is gentle, odorless and easy to handle in the factory.
You will commonly find Diethanolamine Bisulfate in rinse-off products such as shampoos, body washes and face cleansers where stable pH is critical for mildness. It is also used in leave-on items like toners, serums and lightweight moisturizers that aim to match the skin’s natural acidity.
Diethanolamine Bisulfate’s Cosmetic Benefits/Uses
In personal care formulas this ingredient plays one main role that quietly improves both product performance and skin comfort.
As a buffering agent Diethanolamine Bisulfate helps the finished product resist pH drift over time. A steady pH keeps preservatives working at full strength, stops texture changes and supports the skin’s own protective acid mantle. The result is a formula that stays gentle, effective and stable from the first use to the last drop.
Who Can Use Diethanolamine Bisulfate
Because it is mainly a pH buffer and not an active treatment, Diethanolamine Bisulfate suits nearly all skin types including dry, oily, combination and sensitive skin. Its mild nature means it rarely upsets the skin barrier, so even reactive complexions generally tolerate it well. People with a known allergy to ethanolamines or sulfates, however, may prefer to avoid it as a precaution.
The ingredient is produced synthetically without animal-derived components, making it appropriate for both vegans and vegetarians. It is also commonly used in cruelty-free formulations.
Current safety data do not flag special concerns for women who are pregnant or breastfeeding when the ingredient is used at standard cosmetic levels. This is not medical advice and anyone expecting or nursing should always check new products with a healthcare professional just to be safe.
Diethanolamine Bisulfate does not cause photosensitivity, so daytime use does not raise the risk of sunburn. It is water soluble, odorless and does not interact negatively with common skincare actives, making it easy to fit into most routines.
Potential Side Effects/Adverse Reactions
Reactions to topical Diethanolamine Bisulfate can vary from person to person. The points below list potential side effects that may occur, though they are unlikely for the average user when the ingredient is properly formulated and used as directed.
- Temporary stinging or tingling right after application
- Mild skin redness or irritation in very sensitive individuals
- Contact dermatitis in those allergic to ethanolamines or sulfates
- Dryness or tightness if used in an overly high concentration
- Eye irritation if the product accidentally gets into the eyes
If you notice any of these effects, stop using the product and consult a healthcare professional for guidance.
Comedogenic Rating
Rating: 0/5. Diethanolamine Bisulfate is fully water-soluble, leaves no oily film and is used at very low levels, so it does not clog pores or trap sebum. Its sole job is to balance pH rather than add texture or emollience, which keeps comedogenic potential virtually nil.
This makes the ingredient suitable for people who are prone to acne or breakouts.
As with any water-based buffer, the final formula matters more than the buffer itself. A rich cream packed with heavy oils can still provoke congestion even if the buffer rates zero.
Summary
Diethanolamine Bisulfate is a straightforward pH buffer that stabilises water-based cosmetics so preservatives stay active, textures stay consistent and the skin’s acid mantle stays comfortable. It does this by gently neutralising excess acidity or alkalinity, nudging the product back into the ideal range every time it is used.
While effective, it is not especially trendy and is often swapped for better-known buffers like citric acid or TEA, so you will mostly encounter it in legacy formulas or niche gentle cleansers.
Current safety reviews find it non-sensitising and non-comedogenic at typical use levels, giving consumers a wide safety margin. Still, skin can be unpredictable so it is wise to patch test any new product that contains the ingredient before applying it more broadly.