Inactive ingredients in agricultural, pharmaceutical, and other common products have typically been excluded from consideration as potential contaminants in drinking water. However, while these chemicals are inert in certain products, they can still pose hazards when combined with other materials during the drinking water treatment process. A new study from researchers in the McKelvey School of Engineering at Washington University in St. Louis reveals how large this impact might be. … (Graduate student Jean) Brownell discovered that inactive amines, which are used as stabilizing agents in herbicides to increase solubility and reduce drift, may be more important than active agents in herbicides when it comes to forming disinfection byproducts (DBPs) linked to various health risks, though the impacts vary by region and time. The results were published in the April 15 issue of Water Research.