In January 2014, a liquid used to wash coal was spilled into the West Virginia Elk River, a primary municipal water source serving about 300,000 people in Charleston, West Virginia. The spilled liquid was primarily the chemical 4-methylcyclohexanemethanol (MCHM). Other chemicals, including dipropyleneglycol phenyl ether (DiPPH) and propylene glycol phenyl ether (PPH), were present in lower amounts. There were limited data on which to determine whether exposure to these chemicals might harm humans or animals.
In July 2014, the Centers for Disease Control and Prevention/Agency for Toxic Substances and Disease Registry nominated the spilled chemicals to NTP to obtain additional toxicology data. In response, NTP formulated plans to conduct a number of studies to provide more information about the chemicals and their potential health effects. The NTP Research Project Plan was released in December 2014, along with a summary.