Maleic Acid

What is Maleic Acid?

Maleic acid is an organic dicarboxylic acid with the formula C4H4O4, featuring a carbon-carbon double bond between the two carboxyl groups, distinguishing it from saturated counterparts like succinic acid. Synthetically produced via oxidation of benzene or butene, it appears as a white crystalline powder soluble in water. In cosmetics, it falls under functional ingredients rather than active skincare components. Primarily, it acts as a pH adjuster by donating protons to lower product pH into the acidic range optimal for many formulations. As a buffering agent, it resists pH changes from environmental factors or ingredient interactions, preserving stability. Additionally, it serves as a fragrance ingredient, imparting subtle scent notes or masking undesirable odors, enhancing user experience while adhering to safety standards for such uses.

Comedogenic Rating 0/5 Low risk of clogging pores
EWG Safety Rating 1-3 View on EWG →
PubChem View on PubChem →

Roles in Formulation

This ingredient serves the following purposes in cosmetic formulations:

Fragrance ingredient
Contributes scent character and/or masks base odors, shaping the overall sensory experience of the formula (subject to allergen and IFRA considerations).
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

Supports formula stability by maintaining consistent pH levels.

Enhances product sensory profile through fragrance contribution.

Promotes overall formulation performance and preservative efficacy via pH control.

Who It's For

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

Who May Benefit Who Should Avoid
Individuals seeking stable, long-lasting skincare products.
Those with known allergies to dicarboxylic acids.
Users of pH-sensitive formulas like cleansers or toners.
Individuals sensitive to fragrance components.
People with non-comedogenic needs, suitable for all skin types.
People experiencing irritation from acidic ingredients.

Safety Notes

  • Rated low concern (EWG 1-3) with limited data on allergies.
  • Deemed safe for use in cosmetics by regulatory reviews.

Frequently Asked Questions about Maleic Acid

What does maleic acid do in skincare?

It adjusts and buffers pH for stability, and adds fragrance for better sensory experience.

Is maleic acid safe for daily use?

Yes, it has a low safety concern rating and is approved for cosmetics.

Does it cause acne or irritation?

Non-comedogenic with low irritation risk based on available data.