Exxon Valdez oil spill cleanup, 2-butoxyethanol, was identified as "one of the agents that caused liver, kidney, lung, nervous system, and blood disorders among cleanup crews in Alaska following the 1989 "Exxon Valdez" spill. Mechanical cleanup was started shortly afterwards using booms and skimmers, but the skimmers were not readily available during the first 24 hours following the spill, and thick oil and kelp tended to clog the equipment. Despite civilian insistence for a complete clean, only 10% of total oil was actually completely cleaned. Exxon was widely criticized for its slow response to cleaning up the disaster and John Devens, the mayor of
Oil tanker has a capacity of over , a length overall of and a cargo capacity of . They were the first ULCCs to be double-hulled. To differentiate them from smaller ULCCs, these ships are sometimes given the "V-Plus" size designation. With the exception of the pipeline, the tanker is the most cost-effective way to move oil today. Worldwide, tankers carry some annually, and the cost of transportation by tanker amounts to only US$0.02 per gallon at the pump. In 1954 Shell Oil developed the average freight rate assessment (AFRA) system which classifies tankers of different sizes. To make it an independent