Scientists Identify Strange Chemical in Drinking Water Across the US

Hello!

Is there something in the water? The answer appears to be yes.

The Longstanding Mystery

For four decades, scientists have struggled to identify a mysterious “phantom” chemical found in drinking water across the US. All they knew was that it was a byproduct of the disinfectant chloramine, which is commonly used in water treatment. In 2026, that mystery appears to have been solved.

As detailed in a study published in the journal Science, the culprit is what the authors have identified as chloronitramide anion—a chemical previously unknown to science. It is a compound consisting of one chlorine atom, two nitrogen atoms, and two oxygen atoms.

What This Discovery Means

The implications of the discovery remain unclear. While the compound shares similarities with other waterborne chemicals that are regulated because of their toxicity, scientists do not yet know whether chloronitramide anion is harmful to human health. They are therefore urging immediate further research into the byproduct.

“We need to investigate it. We don’t know the toxicity,” said study lead author Julian Fairey, an associate professor at the University of Arkansas, in comments to The Washington Post. “This work was 40 years in the making in terms of trying to identify the compound, and now that we have identified it, we can delve into how toxic this thing is.”

Chloramines in Context

None of this is necessarily cause for alarm. Contaminants are unavoidable in drinking water, and when kept at low enough concentrations they are generally harmless.

Chloramines, formed by combining chlorine and ammonia, have been used to treat water effectively for nearly a century in the US and are also employed in other countries, including Australia. Like many chemical disinfectants, however, they produce byproducts that must be carefully managed. These form when chloramines interact with organic substances in the water, such as harmful germs, and can decompose over time into additional byproducts. The newly identified chloronitramide anion is one such decomposition product.

One advantage of chloramines is that they generate lower concentrations of byproducts already known to be harmful—and in some cases carcinogenic—than chlorine, the most widely used water disinfectant.

Expert Perspectives

Until more research is conducted, the safety of chloronitramide anion remains an open question, though many experts are cautiously optimistic.

“I agree that a toxicological investigation of this anion would be useful now that we know its identity, but I am not overly worried about my tap water,” said Oliver Jones, a professor of chemistry at RMIT University in Melbourne, Australia, who was not involved in the study.

“The question is not whether something is toxic or not—because everything is toxic at the right amount, even water. The question is whether the substance is toxic at the amount we are exposed to. I think here the answer is probably not.”

If anything, greater attention may be warranted for other widespread contaminants, such as microplastics.

Also read: Doctor reveals 10 minute power napping technique that Navy SEALs ‘swear by’ to feel refreshed

Thank you!
Join us on social media!
See you!