PEG-9
What is PEG-9?
PEG-9, also known as polyethylene glycol 9, is a synthetic polymer created through the ethoxylation of ethylene glycol, resulting in a chain of nine ethylene oxide units on average. This water-soluble, low-viscosity liquid belongs to the polyethylene glycol family, commonly derived from petroleum sources. In cosmetics, it appears in moisturizers, cleansers, serums, shampoos, and conditioners. Functioning as a humectant, PEG-9 binds water molecules from the air and lower skin layers, supporting surface hydration. As a solvent, it facilitates the mixing of water- and oil-soluble components, controls product thickness, and enhances the delivery of active ingredients. Its lightweight nature allows it to improve spreadability without greasiness, making it valuable in lightweight, fast-absorbing formulas across rinse-off and leave-on products.
Roles in Formulation
This ingredient serves the following purposes in cosmetic formulations:
Benefits
Enhances skin hydration by drawing and retaining moisture on the surface.
Improves product formulation by dissolving and blending diverse ingredients effectively.
Supports non-comedogenic textures suitable for various skin types.
Who It's For
A quick guide for who this ingredient may suit (and who should be cautious).
| Who May Benefit | Who Should Avoid |
|---|---|
| People with normal to dry skin seeking lightweight moisture. | Those with known sensitivity to polyethylene glycol compounds. |
| Individuals using multi-ingredient products for optimal performance. | People wary of ethoxylated ingredients due to potential impurities. |
| Users preferring water-based, non-greasy skincare and haircare items. | Individuals preferring strictly natural or petroleum-free formulations. |
Safety Notes
- EWG rates it with a consistent score of 3, indicating moderate concern primarily from limited data and contamination risks.
- Cosmetic review panels deem it safe in typical use when manufactured to purity standards.
Frequently Asked Questions about PEG-9
What does PEG-9 do in skincare?
It acts as a humectant to boost hydration and a solvent to blend ingredients for smoother textures.
Is PEG-9 comedogenic?
No, it has a comedogenic rating of 0, making it unlikely to clog pores.
Are there safety concerns with PEG-9?
EWG scores it 3 due to possible impurities; choose high-purity products from reputable sources.