Ingredient dictionary

Iodopropynyl Butylcarbamate

Also listed as: IPBC

A synthetic preservative that stops mold and yeast from growing in water-based products, helping them stay fresh on the shelf. It is on the label of 6 products in our library. Checked against our library November 6, 2026.

What Iodopropynyl Butylcarbamate does

Slows mold and yeast growth
Keeps products fresh on the shelf
Often paired with other preservatives

IPBC is a synthetic preservative, made in a lab from an iodine-containing alcohol and a butyl-based building block. It belongs to the carbamate family of chemicals. Its main target is mold and yeast, which can grow in products that hold water.

Formulators add it in small amounts to keep cleansers, eyeliners and deodorants fresh on the shelf. It is usually stirred in late, when the mix is cool, because heat and high pH can break it down. In the finished product, the small amount means it rarely changes how a formula feels.

Good for

Suits products such as cleansers, eyeliners and deodorants that need protection from mold and yeast.

Frequently asked questions

Is IPBC safe in skincare?

IPBC is widely used and generally well tolerated at the low levels found in cosmetics. Like any preservative, it can cause irritation or allergy in a small number of people. If you have sensitive skin, a patch test on your inner arm is a sensible first step.

Is IPBC natural?

No. IPBC is a synthetic preservative made through chemical reactions. It is not a plant-derived ingredient. Some people prefer preservative-free products, but preservatives like this one are used to keep water-based formulas free from mold and yeast.