LINCOLN — A smelt water explosion in a chemical recovery boiler at Lincoln Paper and Tissue LLC on Saturday shook neighborhood houses and forced the mill to shut down temporarily. No injuries were reported, officials said.

The explosion occurred at the Katahdin Avenue mill’s recovery boiler, which is used to burn or recycle leftover chemicals and materials generated by the pulping process, at about 7:23 a.m. Lincoln, Lowell and Mattawamkeag firefighters cleared the scene about 40 minutes later, said Dan Summers, Lincoln’s public safety director.

“We don’t know why it happened,” said Bill Peterson, the mill’s personnel director and spokesman, “and we won’t know how much damage was done [to the boiler and surrounding structure] until we get a chance to get in there and look at it.”

Already located in a restricted-access area that during weekdays would have been populated by only two or three workers, the boiler will be quarantined for 24 hours to allow any potentially hazardous gases to dissipate, Peterson said. No significant environmental damage is expected.

However, tissue production will likely resume late Saturday or sometime Sunday morning, he said.

Several Katahdin Avenue residents said they slept through the explosion, first realizing trouble when they heard the mill’s warning alarms, which were still audible Saturday afternoon, and firetruck sirens.

Thirty-five-year old Katahdin Avenue resident Laura Burrill was in bed asleep said she heard “what sounded like my furnace backfiring, and then the whole house shook.”

Within 10 minutes, Burrill heard sirens from firetrucks leaving the Lincoln Public Safety Building about two streets away. Hearing loud hissing sounds, Burrill went outside her house and saw steam billowing from a multistory mill building about 75 yards north and slightly west of the mill’s front security building, she said.

“There are all kinds of debris [panels] missing from the building,” Burrill said.

She said missing were at least five of what appear to be large aluminum panels arrayed horizontally along the front of the building about three stories up. Several other panels had been missing for years, Burrill said.

Katahdin Avenue resident Leanna Haines said she heard the explosion. The vibrations from it were strong enough to startle Chevy, her deaf American bulldog, she said.

It was unclear how many workers were near the boiler when the explosion occurred. The federal Occupational Safety and Health Administration and other agencies have been notified of the incident, mill co-owner Keith Van Scotter said.

When the explosion occurred, company officials immediately instituted their incident command procedures, which include counts of workers, and found no one missing, said Van Scotter, who was out-of-state at an industry conference.

Van Scotter described the recovery boiler as burning dissolved lignin, the chemical that binds pulp fibers during the paper and tissue-making process, and as recovering chemicals used to make paper.

Boiler water temperatures typically rise to several hundred degrees Fahrenheit, Peterson said. The system’s alarm controls were damaged in the explosion. Workers would shut off the alarms as soon as they could determine how to, he said.

Peterson was glad that the mill was on its typical near-skeleton weekend staffing. He praised millworkers for following their emergency-response and incident command plans flawlessly.

“Everything worked the way it was supposed to,” Peterson said. “The Lincoln Paper and Tissue family of workers is still intact. That’s No. 1.”