PEG-150 Pentaerythrityl Tetrastearate

Irritancy: unknownComedogenicity: unknownEmulsifying

Fungal-acne trigger

The details

PEG-150 Pentaerythrityl Tetrastearate is an emulsifier, thickener, and mild conditioner. It's made by esterifying and pentaerythritol with stearic acid , and then attaching 150 units of ethylene oxide to make it water-friendly. This structure lets it bridge oil and water to prevent ingredients from separating and keep formulas stable. It is also the reason it gives cosmetics a creamy feel without the greasiness. The CIR Expert Panel has concluded this ingredient to be well-tolerated. Human repeated patch testing on the undiluted version has come back negative for irritation and sensitization. On top of that, its large molecule size makes skin penetration unlikely. Usage concentration ranges from 5% in rinse-off to 1.8% in leave-on formulas. Because this ingredient is made from stearic acid, it may not be fungal acne safe. Stearic acid is a C18 fatty acid that the Malassezia yeast can substrate.