Specialty pool chemical manufacturer United Chemical has begun a study for the U.S. EPA to explore the potential for bromate formation when sodium bromide is use in outdoor pools.
The Piru, Calif.-based company has constructed eight aboveground test pools at its facility. Using those vessels, the company will test over summer for bromate under a number of common use cases for sodium bromide.
The testing is being conducted to fill an information gap regarding the formation of bromate. As the substance is classified as a probable human carcinogen, the EPA made an interim decision in 2021 stating that all registered bromine sanitizers and algaecides containing sodium bromide needed labeling stating, “Not for use in outdoor pools.” The agency cited a lack of data on whether bromate would form from typical outdoor pool use. The required label changes will appear across the industry later this year.
“While there’s indirect evidence to suggest that bromate is unlikely to form in swimming pools, it was important to test that hypothesis -- both to provide the agency and industry with data it lacked, as well as for our own peace of mind,” said United Chemical CEO Scott Hamilton, also the son of founder Jock Hamilton. “My father introduced sodium bromide to the industry ... in the early 1980s. Although we feel confident based on existing evidence that bromate doesn’t form from sodium bromide under typical use in outdoor pools, we felt it was our responsibility to invest in performing the study.
Samples will be sent to the laboratory Eurofin, which will use ion chromatography to test for bromate concentrations.
“While most people know us through our algaecides ... we consider ourselves a science company first," Hamilton said. "My dad built the company on teaching chemistry to the industry. That’s why we will publish all the raw data we collect to the industry. It’s important that this study is as transparent and rigorous as possible. It’s our scientific and ethical duty.”
United Chemical was founded in 1971 by Jock Hamilton, a influential chemical expert and instructor who also created the Hamilton Index for pools.
