While it is difficult to determine the exact amount of oil spilled, these are the best estimates of the world's worst oil spills in history:

1. The Arabian Gulf Spill in Kuwait on January 19, 1991 which spilled about 380-520 million gallons of oil in the Persian Gulf.

2. Deepwater Horizon Spill on April 22, 2010 which spilled about 206 million gallons of oil in the Gulf of Mexico.

3. Ixtoc 1 Oil Spill on June 3, 1979 which spilled 140 million gallons of oil in the Bay of Campeche, Mexico.

4. Atlantic Empress Oil Spill on July 19, 1979 which spilled 90 million gallons of oil in the Coast of Trinidad and Tobago.

5. The Kolva River Spill on August 6, 1983 which spilled 84 million gallons of oil in Kolva River, Russia.