Medical waste caused lab fire, BU officials say

Smoldering medical waste left in a sterilizing machine spawned the cloud of smoke that wafted through a laboratory last month on the campus of Boston University's medical school, city health officials and the university said yesterday.

The March 20 fire forced the evacuation of a 10-story building on the school's South End campus and reignited concerns among neighborhood activists about BU's ability to operate safely a high-security research facility now under construction, where scientists will work with the world's deadliest germs.

Last month's lab fire resulted in no injuries, and city health investigators said no biological material escaped from the lab, which researches tularemia, also known as rabbit fever.

But while officials from BU and the Boston Public Health Commission said the university generally responded appropriately to the fire, the school also acknowledged that events leading up to the fire demonstrated shortcomings that are being addressed.

City health officials, who only learned about the lab fire incidentally, said the episode showed the need to make sure researchers understand the rigorous lab safety regulations adopted after three BU scientists were exposed in 2004 to the bacterium that causes tularemia.

"We learned some things we could do better and will do better," said Jack Murphy, chief of the section of molecular medicine at BU.

Investigations by the city and university showed that the fire began in an autoclave, a sterilizing machine that is a fixture in labs where scientists work with potentially dangerous substances. Gowns, gloves, and research equipment are routinely placed in the devices to be sterilized before they are thrown away.

In late February, researchers in a ninth-floor lab in BU's Center for Advanced Biomedical Research placed two large bags of medical waste in the autoclave.

After running the machine, they discovered that the door was stuck shut, triggering them to close the lab, known as a Biosafety Level-3 facility.

A technician replaced a motor in the door about two weeks later, on a Friday, and researchers were told they could resume their work. But the medical waste was left in the autoclave.

"It was Friday afternoon, and no one took the trash out," said Murphy, "so the waste was being cooked all weekend."

Why wasn't it removed?

"That's a good question," said Stephen Morash, BU's manager for emergency planning and response. "I wish I had a good answer for you."

"If they had removed that bag of trash Friday, this wouldn't have happened," Morash said.

The following Tuesday, March 20, a scientist entered the room housing the autoclave and opened the submarine-like door of the machine, detecting a strong aroma of plastic.

The concerned researcher closed the door but didn't fully seal it.

University officials said the failure to seal the door was not an error because after so many rounds of sterilization, there was no reason to believe the material inside was contaminated.

But because the door was not sealed, the university officials theorize, oxygen entered and caused a reaction that resulted in a fire.

The researcher sent an e-mail to a university safety official about her concern, but the official was on the school's Charles River campus and did not immediately receive the note.

"E-mail is a nice, cool tool, but if you want to make sure something happens, pick up the phone and call me, knock on my door," Morash said. "From hindsight, that's the thing that needs to be worked on."

When smoke began billowing from the autoclave, fire detection systems were sounded, and the Boston Fire Department was summoned.

However, officials from the city's Public Health Commission didn't learn of the fire until three hours later.

Lab safety regulations adopted by the city in 2006 require that certain serious incidents be reported immediately to the health commission.

University officials said that because the incident did not result in injuries or the spilling of dangerous materials, there was no need to immediately alert the city.

"What we said to them is that the regulations say any incidents that happen in a BSL-3 lab, we need to be notified ASAP," said Leon Bethune, director of the Health Commission's Environmental Health Office.

Stephen Smith can be reached at stsmith@globe.com.