What Is Peg-23 Poly(1,2-Butanediol)-21 Propylene Glycol Dimethyl Ether?
Peg-23 Poly(1,2-Butanediol)-21 Propylene Glycol Dimethyl Ether is a lab-made polymer that blends three familiar building blocks: polyethylene glycol, 1,2-butanediol and propylene glycol. Chemists link short chains of ethylene oxide (the PEG part) to 1,2-butanediol, then cap the ends with dimethyl ether groups anchored by a propylene glycol spacer. The result is a water-soluble liquid that behaves like a gentle surfactant and a stabilising helper in emulsions.
PEG-based ingredients have been used in personal care since the 1950s because they clean skin without a harsh feel. As formulators searched for milder alternatives to sulphate detergents, they began tweaking PEG chains with diols such as 1,2-butanediol. This specific hybrid appeared more recently when manufacturers noticed it could lift oil and dirt while also keeping water and oil phases mixed, which reduced the number of separate additives needed.
Production starts with food-grade 1,2-butanediol that undergoes controlled polymerisation with ethylene oxide. Propylene glycol is then reacted to bridge two identical arms, and dimethyl ether caps are added to limit irritation and improve shelf stability. Every step happens in closed reactors to ensure high purity suitable for cosmetics.
You will most often spot Peg-23 Poly(1,2-Butanediol)-21 Propylene Glycol Dimethyl Ether in facial cleansers, micellar waters, makeup removers, lightweight moisturisers, cream masks and leave-on lotions that aim for a fresh non-greasy feel.
Peg-23 Poly(1,2-Butanediol)-21 Propylene Glycol Dimethyl Ether’s Cosmetic Benefits/Uses
This multitasking ingredient earns its place in formulas for two main reasons
- Cleansing: Its surfactant nature breaks the surface tension between oil and water so it can surround grime and makeup, letting them rinse away easily. Because the PEG and diol parts are mild, it cleans without the tight squeaky sensation harsher surfactants can leave behind
- Emulsifying: It positions itself at the border of oil and water droplets, stopping them from separating. This keeps creams uniform, improves texture and ensures every pump or scoop delivers the same mix of active ingredients
Who Can Use Peg-23 Poly(1,2-Butanediol)-21 Propylene Glycol Dimethyl Ether
This gentle surfactant suits most skin types, including normal, oily, combination and sensitive skin, because it cleans without stripping natural oils. Dry or barrier-compromised skin can also tolerate it, though those users may want to pair it with richer moisturisers since the ingredient itself does not add significant hydration.
The material is fully synthetic and contains no animal-derived components, making it appropriate for vegans and vegetarians.
No current safety data suggest special restrictions for pregnant or breastfeeding women when the ingredient is used as directed in rinse-off or leave-on cosmetics. That said, this is not medical advice and anyone who is pregnant or nursing should review their routine with a healthcare provider for personal reassurance.
Peg-23 Poly(1,2-Butanediol)-21 Propylene Glycol Dimethyl Ether is not known to cause photosensitivity, so it will not make skin more reactive to sunlight. It is odourless, colourless and compatible with most common skincare actives, which helps formulators keep products gentle and streamlined.
Potential Side Effects/Adverse Reactions
Responses to topical Peg-23 Poly(1,2-Butanediol)-21 Propylene Glycol Dimethyl Ether vary from person to person. The points below represent potential side effects that might occur, but they are uncommon when the ingredient is used correctly in well-formulated products.
- Mild irritation – fleeting redness or stinging can appear on very reactive skin
- Contact dermatitis – rare allergic reactions may manifest as itching, rash or swelling
- Eye stinging – discomfort may occur if a cleanser containing the ingredient is not rinsed out of the eyes promptly
- Enhanced absorption of other actives – its surfactant nature can slightly boost penetration of accompanying ingredients which might amplify their own irritation potential
- Dryness with overuse – multiple daily cleanses or high concentrations can leave skin feeling tight especially in low-humidity climates
If you experience any of these effects discontinue use and seek guidance from a healthcare professional or dermatologist.
Comedogenic Rating
Rating: 0–1 (virtually non-comedogenic)
Peg-23 Poly(1,2-Butanediol)-21 Propylene Glycol Dimethyl Ether is a small, fully water-soluble molecule with no oily or waxy residues that could clog pores. It rinses clean, does not form an occlusive film on the skin and is used at modest percentages in most formulas. Published ingredient databases list similar PEG surfactants as non-comedogenic, so the expected rating stays at the very low end.
Because of this low rating, the ingredient is considered suitable for acne-prone or breakout-prone skin.
Only if a product contains heavy oils alongside this surfactant could overall pore-clogging potential rise, so assess the full ingredient list rather than this single component in isolation.
Summary
Peg-23 Poly(1,2-Butanediol)-21 Propylene Glycol Dimethyl Ether acts mainly as a mild cleanser and an emulsifier. Its PEG and diol portions attract water while the propylene glycol dimethyl ether end interacts with oils, letting it surround dirt and makeup so they rinse away and also sit at the oil-water interface to keep creams homogenous.
The ingredient is not especially famous but has been gaining quiet traction in micellar waters and gentle cleansers because it offers two functions in one and helps brands avoid harsher sulfates.
Safety profiles show low irritation rates and no known long-term risks when used at cosmetic levels. Still, everyone’s skin is unique so it is wise to patch test any new product that contains this or any other active to check personal tolerance.