PPG-12 (Poly[oxy(methyl-1,2-ethanediyl)], .alpha.-hydro-.omega.-hydroxy-) is a common ingredient used in the cosmetic industry and in hair and skincare products. The term "PPG" stands for polypropylene glycols, and the number "12" indicates the number of propylene oxide units in the chain.

Description of the raw materials:

• Propylene Oxide. Propylene oxide is a key raw material for the synthesis of PPG-12. It is produced through the hydration reaction of gaseous propylene oxide.
• Propylene Glycol. Propylene glycol is used as an initiator in the synthesis of PPG-12. It is a raw material that reacts with propylene oxide to form the polypropylene glycol chain.

Summary of the industrial chemical synthesis process step-by-step:

• Preparation of ingredients. Propylene oxide and propylene glycol are prepared and accurately dosed according to specific proportions required for the synthesis of PPG-12.
• Polymerization reaction. Propylene oxide is reacted with propylene glycol in a chemical reactor, under specific temperature and pressure conditions, to polymerize and form a chain of polypropylene glycols with 12 propylene oxide units.
• Purification of the product. The reaction product undergoes purification processes to remove any impurities or unwanted residual reagents.
• Characterization of the product. The synthesized PPG-12 is characterized through chemical and physical analyses to confirm its identity and evaluate its properties, such as viscosity, solubility, and stability.
• Formulation of the finished product. PPG-12 is incorporated into the formulation of cosmetic or hair and skincare products along with other active and auxiliary ingredients.
• Production of the finished product. The complete formulation is produced in large quantities and packaged in bottles or appropriate containers for distribution and use.

PPG (polypropylene glycol) in small quantities is a safe, biocompatible, biodegradable polymer that produces pyruvic acid, a metabolite that our body uses to produce metabolic energy. It is considered a safe ingredient (1).

What it is for and where

Cosmetics

Skin conditioning agent. It is the mainstay of topical skin treatment as it has the function of restoring, increasing or improving skin tolerance to external factors, including melanocyte tolerance. The most important function of the conditioning agent is to prevent skin dehydration, but the subject is rather complex and involves emollients and humectants that can be added in the formulation.

• Molecular Formula    C₆H₁₄O₃
• Molecular Weight  
• CAS  25322-69-4
• UNII    WNY0H4G53Q
• EC Number  500-039-8
• DTXSID30861722
• Nikkaji   J101.144H

References____________________________________________________________________

(1) Fiume MM, Bergfeld WF, Belsito DV, Hill RA, Klaassen CD, Liebler D, Marks JG Jr, Shank RC, Slaga TJ, Snyder PW, Andersen FA. Safety assessment of propylene glycol, tripropylene glycol, and PPGs as used in cosmetics. Int J Toxicol. 2012 Sep-Oct;31(5 Suppl):245S-60S. doi: 10.1177/1091581812461381.

Abstract. Propylene glycol is an aliphatic alcohol that functions as a skin conditioning agent, viscosity decreasing agent, solvent, and fragrance ingredient in cosmetics. Tripropylene glycol functions as a humectant, antioxidant, and emulsion stabilizer. Polypropylene glycols (PPGs), including PPG-3, PPG-7, PPG-9, PPG-12, PPG-13, PPG-15, PPG-16, PPG-17, PPG-20, PPG-26, PPG-30, PPG-33, PPG-34, PPG-51, PPG-52, and PPG-69, function primarily as skin conditioning agents, with some solvent use. The majority of the safety and toxicity information presented is for propylene glycol (PG). Propylene glycol is generally nontoxic and is noncarcinogenic. Clinical studies demonstrated an absence of dermal sensitization at use concentrations, although concerns about irritation remained. The CIR Expert Panel determined that the available information support the safety of tripropylene glycol as well as all the PPGs. The Expert Panel concluded that PG, tripropylene glycol, and PPGs ≥3 are safe as used in cosmetic formulations when formulated to be nonirritating.