Researchers Find Unknown Chemical in Drinking Water

Scientists discovered chloronitramide anion in chloramine-treated drinking water, highlighting potential health risks and a need for further toxicity research.

Water from a tap fills a glass in San Anselmo, Calif., on July 6, 2023. Justin Sullivan/Getty Images

Scientists have uncovered a new chemical compound lurking in U.S. drinking water, potentially exposing one in five Americans to an unidentified health risk.

Researchers at the University of Arkansas have identified chloronitramide anion, a previously unknown byproduct of water disinfection that could have implications for public health, according to a new study published on Nov. 21 in Science.

Toxicity Still Unknown

The newly identified compound, chloronitramide anion (chemically expressed as Cl–N–NO2⁻), is an end product of inorganic chloramine decomposition. ​While its toxicity remains unknown, researchers are concerned about its prevalence and similarity to other toxic compounds. Further study is necessary to assess its public health risk, the researchers wrote.