In 2002 EPA released a report saying that TCE was more dangerous than anyone thought. This started an avalanche of criticism from other federal agencies like NASA, The Department of Defense, and Department of Energy which rely on TCE because it's a cheap and effective solvent that these departments use in it's daily operations. The result was the Bush Administration telling the EPA to rescind it's 2002 draft review of TCE's toxicity until a Bush Administration appointed National Academy of Sciences
(NAS) TCE Scientific Review Board had time to review all existing data and make it's own recommendations.
Seeing as the scientists were mostly appointed by the military TCE activists were pretty dubious about the outcome of this review...Then last March the NAS came out with it's summary basically upholding the EPA's original draft and recommending that they finish it and enforce it. This was a great day for VOTE.
Below you will find the NAS Brief and their executive summary - the entire document is over 300 pages - so these two excerpts are plenty for the uninitiated.