HARRISBURG -- For years, health care unions have been trying to eliminate, or at least limit, mandatory overtime for nurses and other workers in hospitals and nursing homes.

Under a bill approved unanimously by the state Senate today, they made some significant progress.

House Bill 834, introduced by Rep. Dan Surra, D-Elk, prohibits a health care facility from requiring nurses and other health care employees "to work in excess of agreed to, predetermined and regularly scheduled daily work shifts.''

After completing a 12-hour shift, health care employees can still voluntarily work overtime shifts but they can't be fired for refusing overtime, the bill says.

But there are three exceptions when overtime can still be required. One is an "unforeseeable, declared national, state or municipal emergency;" another is "a highly unpredictable and extraordinary event," such as the Sept. 11, 2001, terrorist attacks; the third is when a hospital or nursing home has large number of unforeseen absences by workers or last-minute calloffs.

Long work hours by nurses and forced overtime can contribute to medical errors and lead to patient deaths, supporters of the bill said.

The measure still needs final approval from the House, which is expected, and would take effect 90 days after Gov. Ed Rendell signs it.