Peg-13 Diphenylol Propane: What Is It, Cosmetic Uses, Benefits & Side Effects

Curious about this ingredient? In this article we're explaining exactly what it is and why it's used within cosmetic formulations.
Updated on: July 1, 2025
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We verify all information on this page using publicly available nomenclature standards from The Personal Care Products Council (PCPC), the European Commission's CosIng database and documentation provided directly by ingredient manufacturers. Our analysis is based on technical data from these sources to ensure accuracy and reliability.

What Is Peg-13 Diphenylol Propane?

Peg-13 Diphenylol Propane is a lab-made ingredient created by attaching about 13 units of ethylene oxide to diphenylol propane, a compound better known as bisphenol A. This process, called ethoxylation, turns the original material into a water-loving substance that blends easily with oils. The result is a clear to slightly hazy liquid or soft solid that dissolves in water and many cosmetic oils.

The story of Peg-13 Diphenylol Propane in beauty products began in the late 1970s when chemists were searching for gentler alternatives to traditional soap-based emulsifiers. By altering bisphenol A with ethylene oxide, they produced a molecule that could hold oil and water together without causing the tight, squeaky feel that soap can leave on skin. Over time this new emulsifier proved stable, easy to use and compatible with many other ingredients so it steadily found its way into modern formulas.

Manufacturing starts with pharmaceutical-grade bisphenol A. Under carefully controlled heat and pressure, ethylene oxide gas is introduced and reacts with the two hydroxyl groups on the molecule. The reaction continues until the average of 13 ethylene oxide units is reached then the mixture is purified to remove unreacted starting materials. The finished product meets cosmetic-grade standards before being shipped to labs and factories.

Because of its strong ability to mix oil and water Peg-13 Diphenylol Propane shows up in a wide range of products such as moisturizers, anti-aging serums, creamy face masks, hair conditioners, sunscreens and liquid foundations. Formulators also use it in leave-on treatments where a smooth, non-greasy finish is important.

Peg-13 Diphenylol Propane’s Cosmetic Benefits/Uses

In everyday skin and hair care formulas Peg-13 Diphenylol Propane serves one main purpose that offers several practical advantages.

Emulsifying: This ingredient keeps oily and watery parts of a product from separating which means creams stay silky, lotions pour smoothly and makeup applies evenly. A stable emulsion also helps deliver active ingredients more reliably and extends shelf life by preventing breakdown over time.

Who Can Use Peg-13 Diphenylol Propane

Peg-13 Diphenylol Propane is generally well tolerated by most skin types including dry, oily and combination because it is used at low levels and is not inherently occlusive or stripping. Very sensitive or reactive skin may wish to proceed cautiously if there is a known history of irritation from emulsifiers or bisphenol derivatives since this ingredient is synthesized from bisphenol A.

The ingredient is fully synthetic and contains no animal derived material so it is suitable for both vegans and vegetarians. Standard manufacturing does not involve animal testing in many regions though cruelty-free certification depends on the final brand’s policies.

Current safety data show no specific risk for women who are pregnant or breastfeeding when Peg-13 Diphenylol Propane is used as directed in cosmetic products. This is not medical advice and anyone who is expecting or nursing should review any skincare routine with a qualified healthcare professional for personal assurance.

Peg-13 Diphenylol Propane does not increase photosensitivity and has no known interactions with sunlight or UV exposure. It can typically be used alongside daytime sunscreens without affecting their performance.

Potential Side Effects/Adverse Reactions

Side effects and reactions to topical Peg-13 Diphenylol Propane can differ from person to person. The following is a list of potential issues that could occur though they remain uncommon when the ingredient is properly formulated and used as intended.

  • Mild redness or stinging on very sensitive skin
  • Allergic contact dermatitis in individuals hypersensitive to bisphenol compounds
  • Transient eye irritation if the product accidentally enters the eyes
  • Theoretical endocrine concern due to the bisphenol backbone though cosmetic exposure levels are extremely low
  • May enhance penetration of other actives which can amplify their irritant potential in some users

If any discomfort, rash or unusual reaction occurs discontinue use immediately and consult a healthcare professional

Comedogenic Rating

Rating: 1 / 5

Peg-13 Diphenylol Propane is largely water soluble and used at low concentrations, so it does not sit on the skin in a heavy, pore-blocking film. Its emulsifying action actually helps disperse oils evenly which further reduces the chance of clogging. The bisphenol backbone brings a small amount of lipophilicity, giving it a theoretical but minimal occlusive potential, hence the rating of 1 rather than 0.

Suitable for most people who are prone to acne or breakouts, though individual reactions can vary.

Because this ingredient can enhance the penetration of other actives, products that pair it with rich plant oils or waxes could feel heavier overall, which might affect blemish-prone skin in rare cases.

Summary

Peg-13 Diphenylol Propane is an emulsifier that keeps oil and water mixed so creams stay smooth, lotions remain stable and actives are delivered evenly. It does this by positioning its water loving ethoxylated side in the water phase while its small oily backbone anchors into the oil phase, creating a sturdy bridge between the two.

It is a niche ingredient rather than a household name, favored by formulators who need reliable yet gentle emulsification without the soapy feel that older agents can leave behind.

Current safety reviews find it non-sensitizing and low in irritation risk when used at cosmetic levels. While most users tolerate it well, trying any new product on a small patch of skin first is always wise to make sure it suits your personal sensitivity level.

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