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Tromethamine

What Tromethamine is & what it does

A buffering agent used to adjust and stabilize a formula's pH and to gel acidic thickeners. It keeps the product gentle and stable.

What is Tromethamine and what does it do in sunscreen?

Tromethamine is a pH adjuster and buffering agent. It is mildly alkaline, so formulators add a small amount to raise and stabilize a product's pH and to neutralize acidic thickeners like carbomer, which only gel properly once their pH is brought up. In a sunscreen this keeps the texture right and the product gentle and stable over its shelf life.

Is Tromethamine safe?

Yes. It is a widely used buffering ingredient that has been reviewed as safe for use in cosmetics at the small levels needed to adjust pH. It works to balance the formula rather than staying active on the skin, and it is well tolerated. It is not a common irritant or allergen at cosmetic concentrations.

Is Tromethamine a preservative?

No. Tromethamine is a pH adjuster and buffering agent, not a preservative, and it does nothing to stop microbes growing. It is easy to confuse because it often sits near other functional ingredients, but the preserving in a sunscreen is done by ingredients like phenoxyethanol or the glycols. Tromethamine is only there to set and hold the formula's pH.

Does Tromethamine clog pores?

No. It is a water-soluble buffering agent used in tiny amounts, not an oil or wax, so it is not a pore-clogging ingredient. It dissolves in the water phase and adjusts pH rather than leaving anything occlusive on the skin.

What else is Tromethamine called?

On a label it appears under its INCI name, Tromethamine. It is also commonly known as TRIS or tris buffer, and chemically as trometamol or tris(hydroxymethyl)aminomethane. All of these refer to the same buffering molecule.

Sunscreens with Tromethamine

We rate 464 sunscreens that contain it, showing the top 10 by overall score:

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