Ships entering North American waters would have to comply with emissions standards once a UN proposal takes full effect.
Members of the UN's International Maritime Organization's marine environment protection committee adopted a plan that creates a 230-mile buffer around U.S. and Canadian shorelines, reports Reuters.
The idea is to control emissions of nitrogen oxides, sulphur oxides and particulate matter from ships.
Most IMO plans take 16 months to be fully adopted, meaning the emissions control area would not be mandatory until July of 2011 at the earliest.
Shipping companies counter that the plan sets arbitrary boundaries using faulty science. Complying with the rules would mean using pricier low-sulphur fuels.
Still, a Japanese envoy at the IMO talks described the new proposal as "weak," reports Business Week. Vessels not meeting the guidelines would face limits on power output.
In response to a similar rule in California, ships have been sailing outside the typical shipping route to the ports of Los Angeles and Long Beach. Complying with the CARB rules for low-sulphur fuel costs up to $30,000 per trip, shipping companies say.
Last fall, shipping companies were more amenable to emissions standards than they are now.
In September, international shipping industry, leary of the prospect of varying national and regional regulations on ship emissions, wanted the United Nations to forge a set of rules that spell out the expectations for maximum emissions.
In 2008, the UN International Maritime Organization put forth regulations on vessel emissions, known as Annex VI of the International Convention for the Prevention of Pollution from Ships, or Marpol.
