One year ago, the Deepwater Horizon drilling rig exploded, spewing oil into the Gulf. During the ensuing month, BP applied an unprecedented amount of chemical dispersants on the surface and under the ocean. From the air alone, they sprayed 972,880 gallons. Still, if the Superdome represented the Gulf, the total amount of dispersants would equal only one teaspoon; the oil itself would be three cans of beer.
Raffi Khatchadourian, a staff writer at The New Yorker, wrote a long, even-handed account of the spill last month that pointed out these figures, as well as examining the implications of the spill. When it comes to the toxicity of dispersants, he writes:
The formula used most widely in the Gulf, Corexit 9500, has seven main ingredients, each of which can be found in products that Americans handle regularly, including Klondike bars, Lubriderm, and ibuprofen. Sorbitan monooleate, for instance, is in juices and shampoos, and hydrotreated light-petroleum distillates can be found in air fresheners.
Unfortunately, there's no one-stop database for finding these foods with FDA-approved Sorbitol-80—also known as Tween® 80 or by its CAS number: 1338-43-8—but because it acts as an emulsifier, you'll find it in everything from vegetable washing soaps to cottage cheese and ice cream. The electron microscope images above show the effects of coating milk fat globules with the emulsifier (left) and without it (right), which, not surprisingly, demonstrate why they might be used for breaking up and dispersing oil.
While the upside to breaking up oil into smaller pieces comes with other risks, one of Khatchadourian's points is that some of the hyperbolic media coverage conflated anything Gulf-related with disaster—even going as far as to cite the dangers of Dihydrogen monoxide, or plain old water. These misinterpretations about Corexit or the everyday applications of dispersant-like substances shouldn't exonerate the oil company. Rather, the ongoing efforts to understand the spill's immense ecological implications should come with some basic scientific literacy.
Photo via "Colloidal Aspects of Ice Cream-A Review." ©1997 Elsevier Science Ltd.