Drinking Water Screening Levels during the Elk River Chemical Spill
On January 9, 2014, corrosion at the bottom of a chemical storage tank operated by Freedom Industries resulted in spillage of approximately 10,000 gallons of chemicals into the Elk River in West Virginia. The spill contaminated the water supply for approximately 300,000 people in the Charleston, W.Va. area. The primary component of the spill was crude 4-methylcyclohexane methanol (MCHM), a liquid used to wash coal. Other chemicals present in smaller amounts included dipropylene glycol phenyl ether (DiPPH) and propylene glycol phenyl ether (PPH).
CDC recommended initial drinking water screening levels for the chemicals present in the spill. Exposure at or below these levels was considered not likely to be associated with adverse health effects. However, at the time, few toxicological studies were available upon which to base screening levels for drinking water.
In July 2014, CDC nominated the chemicals in the Elk River spill to the U.S. National Toxicology Program (NTP) for further study. NTP recently completed its year-long research program to evaluate the chemicals’ potential toxicity. In a final update published July 8, 2016, NTP stated that its findings “support the adequacy of the drinking water screening levels” that CDC recommended. Information from this update appears below.
From NTP’s final update on the West Virginia chemical spill: “The collected findings of the NTP studies support the adequacy of the drinking water screening level concentrations recommended by the Centers for Disease Control and Prevention (CDC) at the time of the spill.… When chemicals did produce effects, they occurred at dose levels that were considerably higher than either the drinking water screening levels recommended by CDC (MCHM and PPH) or the estimated levels of the minor components in the drinking water based on the reported tank contents.”
Editor's Note: Fumes vs. Vapors
The original wording from the Center for Public Integrity's report "Common Solvent Keeps Killing Workers, Consumers" mistakenly refers to "fumes" in a context where "vapors" is the correct term. The Synergist has corrected this error in the digital edition.
Unfortunately, the error found its way into the print version of the November issue. The Synergist regrets the error and will publish a correction in the December issue.
Ed Rutkowski, editor