When limonene (a common fragrance ingredient from citrus) meets chlorinated water—like at a pool or during tap water treatment—it breaks down into multiple chlorinated byproducts. The study found that these byproducts are actually less toxic than the original limonene in lab tests, though the research doesn't assess safety at real-world exposure levels or in your body.

Researchers mixed D-limonene with chlorinated water in a lab and used mass spectrometry to identify what chemical compounds formed. They tested various ratios of limonene to chlorine to see how the reactions changed.

Funding not disclosed in abstract