The regulations require domestic and foreign cargo ships, tankers and cruise vessels sailing in and out of California ports to use cleaner fuel to power their engines and boilers.

The California fuel mandate comes amid similar international efforts, but air regulators say the 27 million Californians who breathe polluted air from the state's ports can't wait for those rules, which are being drafted to take effect in 2015.

"The health of our residents is too important to wait for some other international organisation to take action," said Jerry Hill, a member of the California Air Resources Board.

"The lives saved by the action we took today are significant."

International shipping companies oppose the rules, adopted unanimously by the air board.

They argue California has no jurisdiction to regulate their operations outside the state's coastal zone.

The Pacific Merchant Shipping Association said California at best can regulate only ships within state waters that extend three nautical miles from the coast under a federal law known as the Submerged Lands Act.

The rule adopted on Thursday would cover ships within 24 nautical miles of the coast.

"International ships running in international waters under international treaties should be handled under international laws," said T L Garrett, vice president of the association, which represents about 60 ocean carrier lines and cargo terminals.

"We know it's the right thing to do. The question is, 'Who should be telling us to do it?'"

Source: By DDNEWS