What Is Peg/Ppg-35/9 Copolymer?
Peg/Ppg-35/9 Copolymer is a lab-made blend of two kinds of building blocks: polyethylene glycol (PEG) and polypropylene glycol (PPG). Chemists link these blocks together to form a clear liquid polymer that mixes easily with water and many oils. The numbers 35 and 9 tell us the average size of each block, giving the material a balanced feel that is neither too heavy nor too light.
The roots of this ingredient go back to the mid-20th century, when PEG materials first appeared in personal care goods thanks to their ability to dissolve stubborn raw materials. Over time makers learned that combining PEG with PPG would offer even better performance, so the Peg/Ppg-35/9 version became a staple for formulators who needed a dependable solvent.
To create it, producers start with two simple gases, ethylene oxide and propylene oxide. These gases are added, step by step, to a starter molecule under heat and pressure. By carefully choosing how many units of each gas to add, chemists reach the 35-to-9 ratio that gives the final copolymer its ideal balance of water and oil loving parts.
You will often spot Peg/Ppg-35/9 Copolymer in facial masks, lightweight moisturizers, serums, sunscreens, hair conditioners, liquid foundations and cleansing balms. Its main task in these products is to keep a wide mix of ingredients smoothly blended so the formula stays clear, stable and easy to apply.
Peg/Ppg-35/9 Copolymer’s Cosmetic Benefits/Uses
In beauty formulas Peg/Ppg-35/9 Copolymer serves one key role that brings several practical perks.
As a solvent it dissolves active ingredients, fragrances and colors that might otherwise sit in clumps. This helps makers craft clear, even textures that glide onto skin or hair without streaks. Because everything is fully dissolved the product feels lighter, spreads more evenly and delivers its actives where they are needed. A strong solvent system also cuts the risk of gritty bits or layer separation, boosting the shelf life and overall quality of the finished product.
Who Can Use Peg/Ppg-35/9 Copolymer
Because Peg/Ppg-35/9 Copolymer is light, water friendly and leaves almost no residue, it suits most skin types including oily, dry, combination and sensitive skin. Its low molecular weight helps it rinse away easily so it rarely clogs pores or feels heavy. Very reactive or broken skin might notice a brief tingle if the formula contains a high percentage of the copolymer, but this is uncommon.
The ingredient is made entirely in the lab from petroleum-derived gases, not from animal tissue or by-products. That means products using it are generally acceptable to both vegetarians and vegans unless other animal-based ingredients are also present.
No studies link topical Peg/Ppg-35/9 Copolymer to problems during pregnancy or while breastfeeding. It is regarded as a low-risk solvent that stays on the skin’s surface. Still, this is not medical advice; anyone who is pregnant or nursing should review all personal care products with a qualified healthcare professional before use.
The copolymer is not photo-reactive, so it does not increase sensitivity to sunlight or interfere with sunscreen performance. It works equally well in daytime and nighttime formulas.
Potential Side Effects/Adverse Reactions
Responses to Peg/Ppg-35/9 Copolymer depend on the individual and on how much of the ingredient is in a given product. The points below outline potential side effects, though most people will not experience them when using well-formulated cosmetics.
- Mild skin irritation such as temporary redness or stinging
- Dryness or tightness if used in very high concentrations on already dehydrated skin
- Contact dermatitis in users with pre-existing sensitivity to polyethylene glycol or polypropylene glycol compounds
- Eye irritation and watering if the ingredient accidentally gets into the eyes
- Enhanced penetration of other actives that might themselves be irritating
If you notice any of these reactions stop using the product and consult a healthcare professional for guidance.
Comedogenic Rating
Rating: 0/5. Peg/Ppg-35/9 Copolymer is highly water soluble and leaves minimal film on skin, so it does not block pores or trap oil. Its molecules rinse away readily and have no greasy character, which is why researchers and formulators classify it as non-comedogenic.
Because of this low score the ingredient is generally suitable for people who are prone to acne or frequent breakouts.
No published data link it to fungal acne triggers, and its synthetic origin means it lacks the fatty acids or waxes that sometimes feed Malassezia yeast.
Summary
Peg/Ppg-35/9 Copolymer is mainly used as a solvent that dissolves actives, fragrances and colorants so a formula stays smooth and stable. Its balanced PEG and PPG backbone attracts both water and oil, helping products feel light while spreading evenly.
You will find it in a fair number of modern skincare and makeup items, especially where a clear non-sticky finish is desired, but it is not as ubiquitous as simpler PEG grades.
Regulatory reviews rate it as low risk for topical use. Side effects are rare and typically mild. As with any cosmetic ingredient it is smart to patch test a new product on a small area first to rule out personal sensitivities.