In sensitive individuals, butylene glycol may be irritating to the skin, eyes, and or nasal passages, but it is the least potentially irritating of all the glycols. In addition, since this ingredient is in so many of the products we apply on our skin every day, the concern is that over time, our exposure may be adding up to something that could be potentially harmful to the health of the skin and body. So far, however, scientific studies have shown no harmful effects from the ingredient at current levels and exposures. In fact, this glycol has not been linked to any organ-specific toxicity and is not considered to be carcinogenic, unlike ethylene glycol.