The large chemical spill in West Virginia that left a large swath of residents without running water now involves a second chemical in addition to the lengthy and dangerous-sounding methylcyclohexanemethanol. The tank that was the source of the leakage also contained PPH, which only took up a small amount of the spill and is considerably less toxic than MCHM, but that the disclosure took more than two weeks to come to light has many people angered.

PPH is a "proprietary" mixture of polyglycol ethers that acts as a thinner for MCHM, and reportedly composed only 7.3 percent of the entire mixture. West Virginia state officials learned of the chemical's presence on Tuesday and also pointed out that the previous operation to clean the water supply would have removed the PPH in addition to much higher levels of MCHM.

According to The Charleston Gazette, PPH can "irritate the eyes and skin and is harmful if swallowed. The sheet lists the material as less lethal than Crude MCHM but also says no data are available on its long-term health effects."

In an emailed statement, CDC spokeswoman Barbara Reynolds said:

Given the small percentage of PPH in the tank and information suggesting similar water solubility as MCHM, it is likely that any amount of PPH currently in the water system would be extremely low. However, the water system has not been tested for this material.

The information comes as Freedom Industries and the West Virginia unit of American Water Works enter a legal battle over culpability in the case. Freedom Industries filed for Chapter 11 bankruptcy protection last week.