BANGOR – Though the liquefied natural gas industry goes to great lengths to demonstrate the relatively nontoxic properties of the petroleum product, there is no way to protect against the threat of a devastating fire in the event of a major spill in the waters of Passamaquoddy Bay, a national authority on fuel spills said Saturday.

A terrorist attack most likely would be the cause of such an event, James Fay, professor emeritus and senior lecturer at Massachusetts Institute of Technology, said during an interview.

“We’ve never seen a fire like this,” he said. “The fire at the World Trade Center was caused by the burning of two tanks of jet fuel; this fire would make that one look like a fire in your living room fireplace.”

Waylaid by a messy weather system, Fay spent the weekend in Bangor, unable to make his scheduled presentation Saturday afternoon at the elementary school in Perry. Instead, he visited the Bangor Daily News to explain his opposition to a proposed liquefied natural gas terminal on Passamaquoddy Tribe land at Pleasant Point in Washington County.

Fay’s visit to Maine was organized by the Save Passamaquoddy Bay Three-Nation Alliance, a local group that opposes the LNG project.

Interest in LNG as a fuel for generating electricity is growing rapidly. While there are only a handful of facilities in the United States, more than 30 new ones have been proposed recently.

Produced primarily in the Middle East, Africa and South America, LNG is transported by ship, stored at onshore tank farms and piped underground hundreds of miles to generating plants. LNG is expected eventually to replace coal at generating facilities in the United States.

Fay, who lives in a Boston suburb and summers near Bath, has testified against LNG storage terminals in Maine and around the country, most recently in the Cumberland County town of Harpswell, where local opposition defeated a proposal late last year. A similar proposal was turned down in the town of Corea before Passamaquoddy leaders invited developers’ interest in tribal lands at Pleasant Point.

Fay said Saturday that his greatest concern about LNG is public safety.

Smaller but deadly blazes have occurred as a result of more limited spills, he pointed out, including one during World War II at a tank farm in Cleveland and more recently at a shipping terminal in Algeria.

Transported in large, oceangoing tankers in its superchilled liquid form – at minus 260 degrees Fahrenheit – LNG vaporizes quickly on contact with air, water or the ground. Though the resulting vapor is considered safe to breathe, it is highly combustible. If a major spill meets a spark, Fay said, the resulting inferno could reach 1,000 feet across and send flames as high as 3,000 feet.

The professor said LNG tanker traffic through pristine Passamaquoddy Bay would disrupt the fishing economy and passenger ferry traffic as well as interfere with progress to develop ecotourism in hardscrabble Washington County.

Ultimately, he said, residents should consider whether they want to transform the scenic and undeveloped coastal area into an industrial zone.

“Is this kind of activity really compatible with the aspirations of the community?” he asked.

Fay’s concerns were brushed aside by Dennis Bailey, spokesman for the project’s developer, Quoddy Bay LLC.

Reached by phone for comment, Bailey characterized the academic as “an LNG gadfly … [with] no personal experience.” He called Fay’s theoretical terrorist attack “fearmongering.”

Bailey acknowledged that it’s possible a terrorist attack might split open the hull of a tanker and cause a major conflagration, and it is for that reason that LNG tankers entering Boston Harbor and other densely developed areas are closely guarded.

“But it’s implausible,” he said. “If I were I terrorist … would I rather attack Boston Harbor or Passamaquoddy Bay? It’s far more likely that the Irving station in downtown Perry is going to explode, and we don’t seem too worried about that.”

Bailey said the LNG “industry standard” requires all tankers to be double- or triple-hulled, lessening the likelihood of a spill. Because LNG floats atop the water and vaporizes quickly, he said, a spill poses essentially no danger to fish or wildlife. Coast Guard escorts and mandated safety perimeters around all tankers further minimize environmental hazards, he said.

LNG, Bailey maintained, is “cleaner, less volatile and better protected” than other fuels that routinely enter heavily developed Portland Harbor and other congested waterfront areas.

The Pleasant Point LNG terminal would be constructed on land that is owned by the Passamaquoddy Tribe but protected by development restrictions. Residents of Perry will vote March 28 on whether to approve the project.

If approved, construction may provide work for up to 2,000 people. An estimated 70 full-time positions will be available after operations commence.