After a gasoline-carrying barge exploded at an Exxon-Mobil storage facility near Staten Island yesterday, lawmakers and environmental activists said that the fire on the edge of densely populated New York demonstrated the need to beef up chemical plant safety and security laws.

Attempts in Congress last year failed to require refineries and chemical factories -- particularly the 500 U.S. plants with deadly chemicals that are located near at least 100,000 people -- to size up their vulnerability to terrorist attack and write security plans to address those vulnerabilities. Industry opposition stalled the legislation, and some lawmakers said the plants remained vulnerable.

"If someone wanted to use these plants as weapons, this is indicative of what could happen," said Sen. Jon S. Corzine (D-N.J.), whose plant security bill died on the Senate floor. "Some of these plants have 7 or 8 million people in their plume. Not doing anything about it is one of the largest failures to protect the American people we have." Yesterday's explosion occurred while a barge was offloading 4 million gallons of unleaded gasoline at the Port Mobil facility on the Arthur Kill waterway, which is lined by several chemical plants.

Some lawmakers and environmental groups say safety breaches are akin to security lapses, and have pushed for new laws that require the use of safer processes and elimination of security vulnerabilities at plants. But industry groups have countered that safety and security are different, and have opposed legislation that would give an oversight role to the Environmental Protection Agency; instead, industry lobbyists say the Department of Homeland Security should oversee plant security.

Yesterday, some groups said safety lapses at the Exxon-Mobil petroleum storage facility indicated problems at the plant. State inspectors conducting a routine inspection in July found about 15 violations of state environmental laws, including "conducting transfer of hazardous substances improperly."

An Exxon-Mobil spokesman said those violations were not related to offloading of petroleum products from ships. Environmental groups said that reflected an overall laissez-faire attitude.

"We're just lucky it [Friday's accident] wasn't one of the several dozens of facilities in that area that could threaten millions of people," said Rick Hind, legislative director for Greenpeace, which has pushed for the legislation. "Just one facility in that area [has chemicals that, if spilled] could cover an area of 12 million people within five miles."

A series of federal and academic reports in the past several years have found security and safety deficiencies at chemical companies. In 1999, the Agency for Toxic Substances and Disease Registry found serious shortcomings at more than two dozen plants in two communities the agency did not name. "Most security gaps were the result of complacency and lack of awareness of the threat," the agency said.

Today, the Department of Homeland Security acknowledges the vulnerability. "The department realizes that a lot of work needs to be done in the chemical sector, and it is one of the top priorities," said spokesman Brian Roehrkasse. A bulletin from the department as recently as last week noted that nuclear and chemical plants could be targets of al Qaeda operatives.

Law enforcement agencies have also expressed frustration with some petrochemical plants. In May, Coast Guard officials sent a letter to the Phillips Bayway Refinery located along the Arthur Kill.

Coast Guard officials were upset over the mishandling of a highly explosive tanker of butane that had entered the Arthur Kill only to find that its berth was occupied by another ship. The tanker made an unassisted 130-degree turn, prompting the diversion of other ships in the area out of security concerns, the May 31 letter said.

"The Coast Guard and the New Jersey State Police take butane ship transits in the Port of NY/NJ very seriously," Coast Guard Capt. P.A. Harris wrote to the refinery and the ship pilots. "A cutter and three boats were diverted from important homeland security duties to provide an escort and facility security."

A labor union leader, John Pajak, secretary of Teamsters Local 877, said the incident reflected a "lack of sensitivity to the safety and well-being of the workers and the surrounding community."

Attempts to reach a spokesman for Conoco-Phillips were unsuccessful. Previously, a spokesman has accused the Teamsters of publicizing security lapses as a way of scaring the public after the terrorist attacks of Sept. 11, 2001.

A fireboat works in the Arthur Kill waterway between the Staten Island borough of New York and Woodbridge, N.J.