The 1997 rules, however, allow ratifying nations to establish special zones with more stringent sulfur standards for fuel. Two have been set up, in the North Sea and the Baltic Sea. The United States, which is close to ratifying the 1997 regulations, is studying such a zone for North America.
Because shipping is a global industry, there is widespread agreement among maritime organization member states to establish uniform standards. But the agency's proceedings are complicated by various competing interests: ship owners, regulatory agencies and maritime nations with differing views about how far air quality standards should go.
Some IMO member states are Third World countries with ship registries that make it possible for vessel owners to avoid taxes, labor laws and the tougher regulations of developed nations.
Political pressure, however, has been mounting around the globe to have the maritime organization take a tougher stance on air pollution from main engines.
EPA officials say they want to see significant reductions in emissions from foreign-flagged vessels and regulations for engines on older ships.
"We want IMO standards that reflect the EPA's view on technology and limits," said Margo Oge, the agency's director of transportation and air quality.
In April, the month the IMO talks began, the International Assn. of Ports and Harbors called on the organization to establish more stringent air quality standards.
"Unfortunately, the IMO, because it works on a consensus basis, can fall prey to the lowest common denominator," said Geraldine Knatz, director of the Port of Los Angeles. "But there are too many things happening worldwide this time to have the IMO sit back and do nothing."
The talks also are overshadowed by recent developments at Maersk Inc., the world's largest shipping line. In May, the Danish company announced that all of its ships would switch to clean-burning low-sulfur fuel within 24 miles of California ports.
Maersk further revealed that it is testing pollution controls for ship engines that can reduce nitrogen oxide emissions by roughly 90%.
"Maersk can put pressure on the proceedings," Vagslid said. "It shows that shipping lines can be profitable and protect the environment."
Port officials in Los Angeles and Long Beach questioned whether the IMO could develop new standards soon enough and strong enough to satisfy port officials and state air quality regulators.
Though harbor authorities don't have the legal authority to regulate foreign-flagged ships, they are devising alternative strategies to deal with the vessels while they are in port.
Besides the proposed clean-air plan, both ports have established speed-reduction programs to cut emissions from ships coming into port. In addition, both ports are beginning to supply onshore sources of electricity to ships so they won't have to run their auxiliary engines.
"We'd like to see voluntary efforts as much as we can," said Bob Kanter, director of planning and environmental affairs for the Port of Long Beach. "We've got to convince terminal operators and shipping lines that it is in their best interests to do these things."
