The evacuation of three MIT buildings on Ames Street last month was caused by the deliberate introduction of a small amount of the chemical pyridine into an air-handling system, an investigation has determined. The buildings affected were E17, E18 and E19.
Senior Vice President William R. Dickson immediately ordered an investigation by Campus Police in the wake of the June 25 incident, which he called a "wanton and deliberate act which placed others in a serious degree of discomfort and inconvenience." About 1,000 people had to leave their offices from just before 10am until about 3:30pm. The buildings house several laboratories and a variety of administrative offices.
"When those responsible are apprehended, the Institute will prosecute to the full extent of the law," Mr. Dickson said.
MIT Police Chief Anne P. Glavin has requested the assistance and cooperation of the community in the investigation. She asked community members who may have information to call the department's 24-hour hot line, x3-4545. "All information received will be treated confidentially," Chief Glavin said.
Pyridine can be smelled in concentrations that are well below the levels associated with any health risks, Mr. Dickson said in a memorandum posted throughout the affected buildings after the incident. "Monitoring of building air throughout the day of the incident indicated no measurable concentrations of pyridine," he said.
The MIT Medical Department said no one sought treatment for exposure to the chemical as a result of the incident.
When the odor was detected personnel from Physical Plant, the Safety Office and the Environmental Medical Service were called.
The presence of the odor suggested a chemical spill and the buildings were cleared. MIT emergency teams moved quickly through the buildings with detecting equipment, but there was no evidence of a spill and no indication from the monitoring devices of a measurable concentration of pyridine anywhere in the three buildings. Traces of pyridine were later found on a filter for one of the air-handling systems located on an upper floor of one of the buildings. Traces of the chemical were also found on the floor near the filter.
Investigators concluded that a small amount of pyridine had been sprinkled on the filter, probably by shaking it from a small bottle, and a few drops had fallen to the floor.
A version of this article appeared in the July 15, 1992 issue of MIT Tech Talk (Volume 37, Number 1).