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

POLYPROPANEDIOL-4

Safety grade: A

A lightweight humectant that draws moisture into your skin and helps keep it hydrated throughout the day. This ingredient is commonly used in serums, lotions, and other skincare products to improve texture and give skin a smoother feel.

Graded using: COSING.

Last verified: June 9, 2026