Two workers accidentally triggered a smoke detector in Widener Library yesterday, the latest in a series of recent incidents that have forced Cambridge firemen to evacuate the building.

Two library employees who decided on their own to cut a wooden board for shelves produced enough sawdust to activate an alarm near the old bindery room in the Widener basement at 2:25 p.m., city fire department officials said yesterday.

Foolish

Edward J. Griffin, deputy fire chief yesterday termed the false alarm "foolish and avoidable," adding that after one of the recent incidents, he asked University officials to provide all personnel with written instructions on how to avoid triggering smoke detectors.

"These are very sensitive devices, and workers forget that things like sawdust can set them off," Griffin said.

Frank E. LaMentea, head of financial and business services for Widener, said yesterday he does not expect to adopt Griffin's recommendation.

"We could do it, but Buildings and Grounds (B & G) are the ones that bring in the workers," LaMentea said.

LaMentea, however, confirmed that yesterday's incident was caused not by B & G personnel but by library employees.

B & G officials were unavailable for comment yesterday.

LaMentea added that Widener officials would notify library workers not to construct anything on their own initiative in an attempt to curtail the false alarms.

The Worst

Griffin said the two workers "chose the worst possible place" to saw the board, adding that written instructions could have averted the accidental alarm.

The alarm required the use of two engines and one ladder company.