It was held by the Washington County Special Operations Team at the Hagerstown Fire Department Training Center on Bowman Avenue.
The training exercises were a good way "to reinforce what I already know," said Allegany County Captain Tim Growden, who took part in the residential propane tanker exercise.
About 125 hazardous materials firefighters from numerous counties in Maryland came to Hagerstown for free classroom and hands-on training on such topics as propane emergencies, confined spaces, gasoline tanker emergencies and biological and chemical terrorism, said Greg Socks, Washington County Special Operations coordinator.
"It's been a big success. Next year we want to double the attendance," he said.
The event will be held in Washington County in October next year and will feature confined-spaces exercises and other emergency drills, he said.
On Sunday, firefighters also learned to handle a leaky 6,000-gallon propane tanker truck and propane car fires during the event. A four-door sedan was ignited and rescuers practiced putting out the blaze.
Such vehicle fires are becoming more common with the use of alternative fuels such as propane, said Socks.
A Montgomery County fire instructor taught participants what to do in the event of a chemical warfare or if a biological agent was released.
Firefighters were taught to look for symptoms of the substance, protect the first responders, to detect the presence of chemicals and then proceed with decontamination procedures.
For Baltimore firefighter Jerry Flilipiak, the seminar provided valuable experience working in confined spaces, he said.
"The whole setup was interesting and provided excellent training," he said.