Two key L.A. city council members said Thursday they plan to introduce legislation Friday to require building owners and security contractors to boost training and health care benefits for security guards at the city’s major commercial office buildings.

In the city’s second attempt to improve working conditions for security guards, L.A. City Council President Eric Garcetti and Councilman Jack Weiss said they will propose an ordinance aimed at improving security of “major buildings.”

The proposal would require owners of high-rise commercial buildings and other highly trafficked venues to place on duty personnel that are trained in emergency response. Major building owners would also be required to file periodic reports with the city detailing the level of training provided to security guards and the level of turnover among guards at their buildings.

One of the more controversial elements of the proposal would require security contractors to spend a specified amount on health care for their employees in a bid to reduce turnover among workers.

A previous attempt to impose similar requirements on downtown building owners failed two years ago because of legal concerns; instead, the City Council made the program voluntary.

In their motion, Garcetti and Weiss said those voluntary measures have left the city vulnerable and that more stringent controls are needed.

“In an attack or disaster, private security officers can make split-second decisions that save lives before police and firefighters arrive. The city must ensure that security officers have the necessary training and experience to fulfill this responsibility,” Weiss said.

However, the motion does not specify what the threshold is for a “major building” or how many buildings in Los Angeles would be impacted. Garcetti spokesman Josh Kamensky said those issues would be hammered out in subsequent negotiations with building owners and security contractors.