Aminomethyl propanediol is a chemical compound commonly used in cosmetic formulations as a pH adjuster and buffering agent. It is known for its ability to neutralize acids and maintain a stable pH in formulations, ensuring the product remains effective over time. Due to its compatibility with various active ingredients, aminomethyl propanediol is frequently found in skincare, makeup, and haircare products.

Chemical Composition and Structure
Aminomethyl propanediol has the chemical formula C4H11NO2 and consists of a molecule containing an amine group (-NH2) and two hydroxyl groups (-OH), making it both hydrophilic and capable of neutralizing acids. This structure allows it to effectively stabilize pH levels, a critical function in many cosmetic products.

Physical Properties
Aminomethyl propanediol typically appears as a colorless, clear liquid that is water-soluble with a light, non-irritating odor. It is stable across a wide range of temperatures and pH levels, making it versatile in cosmetic formulations such as creams and gels without altering the product's texture or effectiveness.

Production Process
The production of aminomethyl propanediol involves:

1. Synthesis: The compound is chemically synthesized by linking an amine group to a propanediol chain, forming a stable molecule.

2. Purification: The raw product undergoes purification to remove impurities and byproducts, ensuring high quality for cosmetic and pharmaceutical applications.

3. Formulation: Once purified, aminomethyl propanediol is incorporated into cosmetic formulations to function as a pH adjuster and buffering agent.

Applications

• Skincare: Aminomethyl propanediol is used in a variety of skincare products, such as creams, lotions, and serums, to maintain a stable pH, enhancing the product's compatibility with the skin and boosting the efficacy of active ingredients.

• Haircare: Found in shampoos, conditioners, and other hair treatments, this ingredient helps regulate pH, making the formula gentle on the scalp and hair.

• Makeup: Aminomethyl propanediol is also used in makeup products, particularly foundations and concealers, to ensure formulation stability and a smooth, even application.

INCI Functions:

Fragrance. It plays a very important role in the formulation of cosmetic products as it allows perfume to be enhanced, masked or added to the final product, improving its commercial viability. The consumer always expects to find a pleasant scent in a cosmetic product.

pH adjuster. This ingredient tends to restore the pH of a cosmetic formulation to its optimal value. The correct pH value is an essential determinant for lipid synthesis in the stratum corneum. The average physiological pH value of the face ranges between 5.67 and 5.76. The hair fibre has a pH value of 3.67.

Buffering agent. It is an iingredient that can bring an alkaline or acid solution to a certain pH level and prevent it from changing, in practice a pH stabiliser that can effectively resist instability and pH change.

• Pharmaceuticals: This compound is frequently employed in topical medications and dermatological products, where it regulates pH to preserve the drug's stability and efficacy.

Environmental and Safety Considerations
Aminomethyl propanediol is generally regarded as safe for use in cosmetic products. It is non-irritating and non-sensitizing, though it is important to use it within recommended guidelines to avoid potential adverse reactions. 

It is biodegradable, and its environmental impact is minimal when used appropriately.

Molecular Formula  C₄H₁₁NO₂

Molecular Weight   105.14 g/mol

CAS     115-69-5

UNII    CZ7BU4QZJZ

EC Number  204-100-7

Synonyms:

2-Amino-2-methylpropane-1,3-diol

2-Amino-2-methyl-1,3-propanediol

Trade name:

• AMPO
• Ammediol

References__________________________________________________________________________

Becker LC, Bergfeld WF, Belsito DV, Hill RA, Klaassen CD, Liebler DC, Marks JG Jr, Shank RC, Slaga TJ, Snyder PW, Gill LJ, Heldreth B. Safety Assessment of Tromethamine, Aminomethyl Propanediol, and Aminoethyl Propanediol as Used in Cosmetics. Int J Toxicol. 2018 May/Jun;37(1_suppl):5S-18S. doi: 10.1177/1091581817738242. 

Abstract. The Cosmetic Ingredient Review (CIR) Expert Panel (Panel) reviewed the safety of tromethamine, aminomethyl propanediol, and aminoethyl propanediolas used in cosmetics. All 3 ingredients are reported to function in cosmetics as pH adjusters, and tromethamine and aminomethyl propanediol are also reported to function as fragrance ingredients. The Panel reviewed relevant animal and human data related to these ingredients, along with a previous safety assessment of aminomethyl propanediol. The Panel concluded that tromethamine, aminomethyl propanediol, and aminoethyl propanediol are safe in cosmetics in the practices of use and concentration as given in this safety assessment.