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Iodopropynyl Butylcarbamate

What Iodopropynyl Butylcarbamate is & what it does

A preservative effective against fungi, often added to broaden a preservative system. It is used at very low, regulated levels.

What is Iodopropynyl Butylcarbamate and what does it do in sunscreen?

Iodopropynyl Butylcarbamate is a preservative, used to stop fungi and other microbes from growing in a product. It is especially good at the mould-and-yeast side of preservation, so brands add it to round out a preservative system. It keeps a sunscreen safe and stable over its shelf life and is used at very low, regulated levels.

Is Iodopropynyl Butylcarbamate safe?

Yes, at the strictly limited amounts allowed in cosmetics. It is a potent preservative, so regulators cap how much can be used and restrict it in some product types, and brands work well within those limits. Without preservatives like it, a water-containing product would spoil and become unsafe to use.

Is Iodopropynyl Butylcarbamate a preservative?

Yes. Its only role is preservation, with a particular strength against fungi such as mould and yeast. That is why it usually appears very low on an ingredient list, often alongside other preservatives that cover bacteria, so the system protects the product on all fronts.

Can Iodopropynyl Butylcarbamate irritate the skin?

It can, in a small share of sensitive people, which is exactly why it is kept at very low concentrations. Most users tolerate it without any issue. If your skin reacts easily to many products, patch-testing a new sunscreen first is sensible.

Does Iodopropynyl Butylcarbamate clog pores?

No. It is used in trace amounts purely to preserve the product, not as an oil or emollient, so it is not considered pore-clogging. Any breakouts from a sunscreen are far more likely to come from the richer ingredients in the formula.

Sunscreens with Iodopropynyl Butylcarbamate

We rate 122 sunscreens that contain it, showing the top 10 by overall score:

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