Most of the 600 inspections of unsafe buildings performed by a group of inexperienced and uncertified inspectors for the Department of Licenses and Inspections last month appear to be invalid, The Inquirer has learned.

In an e-mail Wednesday, officials of the state's Department of Labor and Industry said that inspections that follow the tenets of the Pennsylvania Uniform Construction Code must be performed by a person certified under the UCC.

"Any UCC inspection not performed by a UCC-certified individual is not valid," Department of Labor and Industry officials concluded.

The vast majority of the 600 inspections - involving 100 to 200 individual structures - fell under UCC code, according to people in Philadelphia familiar with the situation. State guidelines required those inspections to have been conducted by UCC-certified inspectors.

Furthermore, city officials have acknowledged that the inspectors themselves were not certified under the code.

The Department of Labor and Industry concluded that the inspections "would require an appropriately UCC-certified individual to conduct an acceptable inspection."

On Monday, The Inquirer reported that nine newly hired inspectors without certification recorded their work in the L&I database under the name of a more experienced inspector with the agency.

Licenses and Inspections Commissioner Carlton Williams wrote in an e-mail to The Inquirer that the nine were being trained "by performing actual inspections on properties that are classified as unsafe" - badly damaged or deteriorated. They would then input their findings in the agency database. They were not yet set up in the system, and so were compelled to all sign in as the experienced man, he said.

Williams added that while the trainees were not certified, they were nevertheless qualified to do the work because they had passed standardized building-code testing.

On Wednesday, state officials disagreed, writing: "In order for any inspection for UCC to be legal, the individual must maintain a valid UCC certification issued by Labor & Industry."

City officials did not address the specifics of the Labor and Industry findings.

Mayor Nutter's spokesman, Mark McDonald, wrote: "With a significant infusion of new funding, staff, and other resources, the City of Philadelphia is increasing the capacity of L&I to protect public safety. New inspectors are getting comprehensive training both in the classroom and in the field in order to implement the new requirements of a greatly strengthened regulatory framework aimed at protecting Philadelphians as the city transforms with new development."

Disputing Williams' assertion that the inspections were a training exercise, L&I personnel said they were an attempt by the agency to quickly clear up a backlog of uninspected, unsafe buildings.