A newly created database of New Yorkers deemed too mentally unstable to carry firearms has grown to roughly 34,500 names, a previously undisclosed figure that has raised concerns among some mental health advocates that too many people have been categorized as dangerous.

The database, established in the aftermath of the mass shooting in 2012 at the Sandy Hook Elementary School in Newtown, Conn., and maintained by the state Division of Criminal Justice Services, is the result of the Safe Act. It is an expansive package of gun control measures pushed through by the administration of Gov. Andrew M. Cuomo. The law, better known for its ban on assault weapons, compels licensed mental health professionals in New York to report to the authorities any patient “likely to engage in conduct that would result in serious harm to self or others.”

But the number of entries in the database highlights the difficulty of America’s complicated balancing act between public safety and the right to bear arms when it comes to people with mental health issues. “That seems extraordinarily high to me,” said Sam Tsemberis, a former director of New York City’s involuntary hospitalization program for homeless and dangerous people, now the chief executive of Pathways to Housing, which provides housing to the mentally ill. “Assumed dangerousness is a far cry from actual dangerousness.”

The way the law has played out, local officials said, frontline mental health workers feel compelled to routinely report mentally ill patients brought to an emergency room by the police or ambulances. County health officials are then supposed to vet each case before it is sent to Albany. But so many names are funneled to county health authorities through the system — about 500 per week statewide — that they have become, in effect, clerical workers, rubber-stamping the decisions, they said. From when the reporting requirement took effect on March 16, 2013 until Oct. 3, 41,427 reports have been made on people who have been flagged as potentially dangerous. Among these, 40,678 — all but a few hundred cases — were passed to Albany by county officials, according to the data obtained by The Times