A US environmental group has raised concerns over the use of a dispersant being used to tackle the oil leak threatening disaster along the Gulf Coast, saying its impact on marine life was unclear.
Published: 7:00AM BST 07 May 2010
Larry Schweiger, National Wildlife Federation head, said the method of using underwater dispersant at the source of the leak was untested and could have devastating effects.
"The problem with putting the underwater dispersant where they're putting them is that they've never done that before," said Mr Schweiger.
He said concerns included how the chemical would migrate after being deployed and whether it would severely harm marine life since it was already deep underwater, unlike when it is deployed on the surface.
"The increasing use of dispersant has left a number of questions about where this material is moving to," said Mr Schweiger.
The US Environmental Protection Agency acknowledged in a statement that the ramifications of the underwater dispersant were unclear and said it had only authorized two tests of the method for that reason.
"The tests were done to determine if the dispersant would be effective in breaking up the oil and helping to control the leaks," the EPA said.
"No further use of dispersants underwater is planned until BP provides the results of these tests for our review."
The agency said "the effects of underwater dispersant use on the environment are still widely unknown, which is why we are testing to determine its effectiveness first and foremost."
It noted that BP remains authorised to use the dispersant on the water's surface.
An organisation representing Gulf Coast shrimp fishermen has also raised concerns about the use of dispersants.
An official from US oceans and weather agency NOAA, Doug Helton, said dispersant was one tool to fight the oil leak and "any response technique is a tradeoff."
He stressed the importance of fighting the slick offshore, before it enters fragile wetlands on the Gulf Coast.
The leak from a British Petroleum well in the Gulf is spewing out oil at a rate of some 5,000 barrels, or 210,000 gallons, a day.