Sulfuric acid could leak from a sunken ship and potentially explode near the southern coast of China during a salvage operation, an official said. The State Oceanic Administration said the Kenos Athena, carrying 7,000 metric tons of concentrated sulfuric acid and 140 metric tons of residential fuel oil, sank March 13 in waters near Zhelang Island off Guangdong province, China Daily reported. Authorities are considering two different salvage methods for the ship, registered in South Korea, but both pose the risk of the sulfuric acid leaking and if it touches water, it could explode, an official who requested anonymity told China Daily. One method would involve removing the sulfuric acid tank, then setting the ship upright and pumping it so it could float. The other method would entail first salvaging the ship, then removing the sulfuric acid. China Central Television reported the first method would take about 25 days, the second, about 50 days. No decision has been made but officials are leaning toward removing the tank, then setting the ship upright, the station said. An oil slick covered about 8-9 1/2 square miles the ocean\'s surface southwest of the shipwreck, the SOA\'s South China Sea Branch said. When it touches water, sulfuric acid reacts violently, releasing extreme heat, and a spill of the acid would change the pH value in the water, which could threaten marine plants and animals, a marine environmental forecaster told China Daily.