WARREN – Three independent corrections inspectors have probed the Maine State Prison inside and out and recommended the maximum-security facility for national accreditation.

It means that, for the first time in Maine history, the state’s largest penal institution has earned a shot at national accreditation, Warden Jeffrey Merrill said Thursday.

“The old facility never would have made it,” he said, referring to the state prison in nearby Thomaston that was torn down in 2002.

Bolduc Correctional Facility in Warren was inspected at the same time, and Maine Correctional Center in Windham and Long Creek Youth Development Center in South Portland earned accreditation from the American Correctional Association, based in Lanham, Md., in recent months.

In March, Merrill will go before the ACA board in Maryland to review the team’s findings, answer questions about weaknesses, and, presumably, receive certificates of accreditation.

From inside prisoner cells to the bottom of employees’ purses, the prison met safety standards on a national level, Merrill said. For example, female employees used to bring in aerosol hair spray in their pocketbooks, which can be dangerous in the wrong hands. That practice was banned.

For three years, the Maine State Prison has been preparing for the visit from the team of independent inspectors, Merrill said. The state had never attempted accreditation at the Thomaston prison because of its shortcomings.

During the 2 1/2-day review, the Maine State Prison and the Bolduc units were inspected for compliance with 493 standards, ranging from record keeping to cleanliness. Of those standards, 44 are mandatory life and health safety standards, Merrill said, meaning that if those requirements are not met, the inspection terminates.

Maine State Prison and Bolduc scored 100 percent on mandatory requirements. At least 90 percent of non-mandatory standards must be met. Maine State Prison scored 98.3 percent, and Bolduc, 98 percent.

An example of unmet standards: not having enough shower heads per inmate due to overcrowding, Merrill said. He said that is beyond the prison’s control.

At the March session, the ACA board could adjust the scores higher if the noncompliance is explained, Associate Commissioner Denise Lord said Friday.

All three inspectors are experienced prison administrators, Merrill said, who focused on different areas. One evaluated prison security at both facilities. Another inspector reviewed some 800 administrative files. The third team member conducted a “white glove” inspection of the prisons for cleanliness and organization.

Staff and inmates were questioned by inspectors on various issues during 15-hour days spent exploring the inner workings of the prisons. For example, a guard might be asked how many keys he has in his possession and what each is for, Merrill said.

Keeping records for such large facilities is a daunting task, he said, noting the administration has to account for every tool in the prison, where inmates crank out wood furniture and products for retail sales at the state’s Thomaston showroom.

“We have over 6,000 drill bits,” administrative coordinator Bob Costigan said. “You have to know where they are.”

More than 500 fire extinguishers are checked monthly, and housing units are inspected daily. In November, maintenance workers completed more than 500 work orders.

Every action must be documented and each item inventoried, Merrill said, praising the staff for a remarkable accomplishment.

“We were committed to passing the first time,” Merrill said. “Now our mission is to maintain these standards and the documentation.”