Link: http://www.ewg.org/reports/withknowledge/

MTBE is a gasoline additive used in the USA for the last 10 years in order to make gasoline burn more cleanly. It was used extensively by petroleum companies until evidence emerged that it is environmentally toxic. Many states have enacted bans on the use of MTBE in recent years.
Currently, legislation is being formulated to try and limit oil industry liability for the use of MTBE, on the grounds that the use of MTBE was not the industry's choice; it was mandated by environmental legislation in the 1990s. Unfortunately, this is a defective on 3 counts:

- There is a lot of evidence that the oil industry decision to use MTBE was the industry's decision, and was not mandated or required by anybody but themselves
- There is a lot of evidence that the oil corporations knew of the environmental toxicity of MTBE, but ignored it, because its usage as a gasoline oxygenator allowed them to shift from having to dispose of it as an unwanted by-product of refining, to actually being able to sell it as a profitable part of their product mix
- The legislation attempts to retrospectively toss lawsuits filed since 2003 over the use of (and environmental damage caused by) MTBE

The above link provides some insight into attempted congressional gerrymandering to limit oil industry liabilities. To my dismay, this legislation is being supported by representatives from my state of Texas, which happens to be the headquarters for some of the key corporations that used (and continue to use) MTBE. Once again, Texas legislators appear to be trying to "fix" the legislative landscape to let their clients off the hook...