PORTLAND — The runaway oil train that caused explosions and fires that killed 47 people in a Quebec town underscored the dangers of transporting hazardous materials via rail. But there are other materials as dangerous as oil that are shipped over rail lines in Maine.

On any given day, freight trains rumbling through Maine’s cities and across the countryside carry hazardous materials that have the potential to start fires, ignite explosions, harm the environment, make people ill and, in extreme cases, even kill.

Besides transporting oil, trains last year also carried about 20 other kinds of materials through Maine that are classified as hazardous, including chlorine, ammonia and sulfuric acid, according to records supplied by the Maine Department of Environmental Protection through a Freedom of Access request by The Associated Press. Those materials weighed a total of more than 300,000 tons and were bound for paper mills, chemical companies, a distillery, energy companies and other destinations both in and out of Maine.

Some materials labeled as hazardous are relatively harmless, such as paraffin wax and potassium chloride, a salt substitute, said University of Maine chemistry Professor Ray Fort. And while crude oil is dangerous because it can be explosive, many of the other materials are dangerous in different ways.

A spill of chlorine or ammonia, for instance, could be devastating because they damage lungs and mucous membranes if inhaled. Chlorine gas was used as a weapon during World War I.

“They would be environmental disasters of a different sort,” Fort said. “Chlorine is really nasty stuff.”

Trains carrying crude oil across Maine have come under scrutiny after an unattended Montreal, Maine & Atlantic Railway train barreled into Lac-Megantic, Quebec, derailed and set off explosions and fires that killed dozens of people and leveled much of downtown. The railroad is based in Hermon, Maine, and Lac-Megantic is about five miles from the Maine border.

Oil can be a dangerous material, but so are many other gases, liquids and solids that Montreal, Maine & Atlantic and Pan Am Railways reported to the DEP last year.

Capt. Mike Nixon of the Portland Fire Department said trains in Portland aren’t too susceptible to derailments because the tracks are relatively straight and trains travel at relatively slow speeds through most of the city. In his nearly 20 years as a firefighter, he’s only responded once to one hazardous spill from a train, when muriatic acid leaked from a rail car in 1991.

Nixon’s bigger concern is hazardous materials transported by truck. “Think about it,” he said. “How much of this material comes by truck?”

Robert Gardner, technological hazards coordinator for the Maine Emergency Management Agency, agreed that trucks have a greater likelihood of an accident than trains do. However, he added, there’s a vast difference in the volumes they carry.

“Trucks carry smaller amounts but we have more trucks on the road than we have rail cars. Rail cars when they derail, because of the amounts involved, have a greater risk,” he said. “A large propane tractor-trailer will hold maybe 9,000 gallons of propane. A rail car will hold 30,000 gallons. “

In his 17 years with MEMA, Gardner recalls three times that residents had to be evacuated because of a hazardous material spill from a train derailment.

As common carriers, railroads are required to ship any commodity that a company requests, said Cynthia Scarano, executive vice president of Pan Am Railways.

Tank cars have become much safer over the years, she said, and railroads, regulatory agencies, and first responders are better trained to respond to spills. Railroads also are required to take extra safeguards when handling hazardous materials, she said.

Montreal, Maine & Atlantic will no longer transport oil, Chairman Ed Burkhardt told the Montreal Gazette on Monday. Railroad President Robert Grindrod didn’t return a phone call for comment.

Hazardous materials can be found just about anywhere, Gardner said. A 20-pound propane tank used for a gas grill is the equivalent of 100 pounds of dynamite, he said.

He urged people who live along rail lines used to transport dangerous cargo to have a disaster-response plan in place.

“Everyone should have an emergency plan for themselves, ‘What do we do if?'” he said. “And it doesn’t matter if it’s a power outage, a hurricane, a river flooding or if you’re on a route for hazardous chemicals.”