Several supervisors on the Fairfax County Board called for an investigation yesterday after learning that Warren E. Isman had taken 43 weeks in leave during his first four years as the county's fire chief.

Their reaction came to a report in yesterday's Washington Post that detailed Isman's leave, most of which has been compensatory time, and his speeches at fire conferences and organizations around the world.

"I was absolutely amazed and shocked," Vice Chairman Martha V. Pennino (D-Centreville) said of Isman's time away from the department. "If he's so damned good, he better be spending his time in Fairfax County and not running all over the world. Frankly . . . if he can be absent that long from the county we don't need him."

Pennino called for an executive session to discuss whether Isman should be fired and to consider whether top officials like Isman, who is paid $75,877 a year to run one of the county's largest agencies, should be eligible for compensatory time.

"Comp time is clearly not appropriate" for top officials, said Supervisor Thomas M. Davis III (R-Mason), also calling on board members, all of whom are on Tuesday's ballot, to review the issue.

According to his county leave records, Isman has earned more than 43 weeks in compensatory time since he was hired in July 1983, and he has used 26 weeks of it during the four-year period.

Isman, who could not be reached for comment yesterday, has said in interviews that he earned the compensatory time by making after-hour visits to the county's 31 fire stations, working late in his Fairfax City office and attending civic association and other night meetings.

All county employes except the county executive are eligible for comp time, but most top officials said they do not use what they earn because they cannot get away from their demanding jobs.

Isman has said he delegates "a great deal" of authority to his staff and vigorously disputed contentions from within the fire department that administrative duties are delayed when he is away.

In response, Eric S. Lamar, president of the Fairfax County Professional Fire Fighters, which represents most of the county's 950 firefighters, said that low-level promotions and grievances are routinely delayed. "Chief Isman may say that 'nothing waits for him,' but many things go undone in his absence," Lamar said.

"We're outraged at the comp time statistics," he said. "In order to be promoted in the fire department now, we are expected to attend many extra training classes on off-day time with no compensation. The idea that the fire chief receives comp time for going into a fire station is incredible."

Isman has used part of his compensatory time, as well as annual and administrative leave, to travel abroad and give speeches. He said his foreign trips have been paid for either by the governments and organizations he visited or by himself.

The fire chief maintains that he does not travel a lot. However, during one 13-month period he traveled to Singapore, the Netherlands, Israel and New Zealand and twice to Australia, according to his 14-page resume. During the same period, he attended work-related conferences in Memphis, Dallas and Williamsburg, county travel vouchers stated.

While most officials had sweeping praise for the fire and rescue department, county supervisors -- including Davis, Chairman John F. Herrity, Audrey Moore (D-Annandale) and Elaine N. McConnell (R-Springfield) -- said yesterday that they want to know more about Isman's leave and activities away from the job, including his fire and rescue consulting business.

Moore, who is challenging Herrity for the chairman's seat, said she was "shocked" upon learning of Isman's time away from his job but would reserve judgment pending a review. Herrity said he "doesn't make rash statements without checking out the facts first."

County board members, and candidates hoping to unseat them on Tuesday, questioned the propriety of engaging in related outside work.

"Don't our supervisors exert any oversight?" said Linda Douglas, a Republican running against Pennino. "He's {Isman's} not just any top county staff person; his job is to oversee emergencies."

Richard King, deputy county executive for public safety, and County Executive J. Hamilton Lambert have defended Isman. King said he had no comment yesterday; Lambert could not be reached for comment.

Referring to an earlier statement from Lambert that leadership of the fire and rescue department is "superb," Pennino said the county executive "appears to be defensive." Said Pennino: "My phone is ringing off the hook. People are upset."