WHEN THE DEEPWATER Horizon rig exploded, BP was presented with a stark choice: Let the oil float to the surface, reach the shore, and allow the world to see the full scope of the damage; or hit as much of the oil as possible with toxic substances called dispersants to break it up into trillions of tiny droplets, keeping some of it from reaching the surface and making landfall—but also potentially killing more sea life than the oil might have destroyed by itself. The company chose the latter. By late July, it had applied a record 1.8 million gallons of dispersants, spraying them on the sea's surface and injecting them directly at the well site, a technique never tried before.
Why, you might ask, was BP able to pump the Gulf full of chemicals that have never been tested for their human and environmental safety? The answer lies, in part, in the Toxic Substances Control Act, the 34-year-old law that governs the use of tens of thousands of hazardous chemicals. Under the act, companies don't have to prove that substances they release into the air or water are safe—or in most cases even reveal what's in their products.