PEG-4 is graded A (Safe) by Expert·ING, based on COSING, FDA regulatory data.

PEG-4

Safety grade: A

PEG-4 is a lightweight liquid derived from petroleum that acts like a moisture magnet for your skin. It's commonly used in skincare and cosmetic products to help them mix together smoothly and feel hydrating.

PEG-4 draws moisture into the skin and helps dissolve other ingredients, making products feel silkier while keeping them from separating.

Graded using: COSING, FDA.

Last verified: May 26, 2026