What it is
Iodopropynyl butylcarbamate is an iodine-containing carbamate that is effective against molds, yeasts, and many bacteria, and is widely used to keep cosmetic and personal-care formulas microbiologically stable. It is active at very low concentrations and is often paired with other preservatives for broad coverage. In sunscreens it serves purely as a preservative and has no role in UV protection.
Safety & warnings
IPBC is a recognized contact allergen and can cause allergic contact dermatitis in sensitized individuals, which is why its permitted concentration in leave-on and rinse-off products is restricted. Because it releases iodine, it is generally not used in products intended for very young children in some markets. Most people tolerate it at the low regulated levels used.
Origin & sourcing
Synthetic organic preservative.
History
IPBC was originally developed as a wood and industrial preservative and was later adopted for use in cosmetics, where its use level is restricted by regulators.
Questions everyone asks
What is IPBC used for?
It is a broad-spectrum preservative that protects the product from molds, yeasts, and bacteria; it does not provide sun protection.
Can it cause skin reactions?
It is a known contact allergen and can cause allergic contact dermatitis in sensitized people, so its concentration is limited by regulators.