Peg/Ppg-20/9 Copolymer: 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/Ppg-20/9 Copolymer?

Peg/Ppg-20/9 Copolymer is a man-made ingredient created when 20 units of ethylene oxide join with 9 units of propylene oxide in a controlled reaction. The result is a block copolymer that looks like a clear to slightly hazy liquid and mixes easily with water and oils.

The idea of blending ethylene oxide and propylene oxide has been around since the mid-1900s, when chemists looked for gentle yet effective cleaners for personal care. Over time they fine-tuned the recipe, arriving at the 20/9 ratio used today because it balances cleaning power with skin feel.

Production starts with propylene glycol. Ethylene oxide and propylene oxide gases are added one after the other under heat and pressure. Each gas links onto the growing chain, giving the finished polymer its distinct sections that attract both water and oil. After purification the liquid is ready for cosmetic labs.

You will find Peg/Ppg-20/9 Copolymer in face cleansers, micellar waters, makeup removers, exfoliating masks, shower gels, shampoos, conditioners, body lotions and even leave-on anti-aging serums. Its ability to dissolve grime while staying mild makes it a staple across skin and hair care lines.

Peg/Ppg-20/9 Copolymer’s Cosmetic Benefits/Uses

This ingredient earns its spot in formulas by tackling several practical jobs

• Cleansing – Lifts away dirt oil and makeup without stripping natural moisture so skin and hair feel fresh yet comfortable

• Solvent – Helps other ingredients like fragrances pigments and active extracts spread out evenly so the product stays uniform from the first pump to the last

Who Can Use Peg/Ppg-20/9 Copolymer

This ingredient is generally well tolerated by all skin types including dry, oily, combination and sensitive. Its mild cleansing nature means it rarely upsets the skin’s natural barrier, so most people can use it without problems. Those with very reactive or allergy-prone skin might still prefer to choose fragrance-free formulas that contain it, just to limit total irritant load.

Peg/Ppg-20/9 Copolymer is synthesized in a lab from petrochemical feedstocks, so no animal-derived materials are involved. That makes it suitable for vegans and vegetarians as long as the rest of the product also meets their standards.

Current safety data show no specific risks for pregnant or breastfeeding women when the ingredient is used topically in cosmetics. This is not medical advice and anyone who is pregnant or nursing should check with a healthcare professional before adding new products, just to be safe.

The polymer does not increase sun sensitivity, so there is no special need for extra sun precautions beyond everyday sunscreen use.

Potential Side Effects/Adverse Reactions

Reactions to Peg/Ppg-20/9 Copolymer can vary from person to person. The points below list potential but uncommon side effects. When used at the levels allowed in cosmetics most people will not notice any problems.

  • Mild skin irritation such as redness or stinging, more likely on broken or highly sensitive skin
  • Eye irritation if a cleanser or shampoo gets into the eyes
  • Contact dermatitis in individuals allergic to polyethers or related compounds
  • Dryness if used in very high concentrations without added moisturizers

If any discomfort, itching or rash develops stop using the product and seek medical advice if symptoms persist.

Comedogenic Rating

Rating: 1/5 Peg/Ppg-20/9 Copolymer is highly water soluble and does not leave an oily film on skin, so it has very little tendency to clog pores. It rinses off easily and is usually blended at low to moderate levels, which further reduces any build-up risk. Because it is a large molecule it does not readily penetrate pore openings where blockages form. Overall it is considered safe for those prone to acne or breakouts, though individual reactions can vary.

Formulas that pair this polymer with heavy plant oils or waxes may have a higher overall comedogenic potential, so always look at the full ingredient list when assessing a product.

Summary

Peg/Ppg-20/9 Copolymer works mainly as a cleanser and solvent. Its water-loving and oil-loving segments help it grab dirt, sebum and makeup then lift them away with a simple rinse. At the same time it keeps fragrances, pigments and actives evenly dispersed so each use delivers consistent results.

While not the most talked-about ingredient on social media, it is a quiet staple in many mainstream cleansers, shampoos and micellar waters because formulators value its balance of gentleness and performance.

Current research and cosmetic regulations rate it as low risk for irritation or toxicity when used as directed. Still, skin is personal so it is wise to patch test any new product containing this polymer before full use just to be sure it agrees with you.

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