In response to recent mass shootings at U.S. workplaces, 52 percent of employers have updated or implemented a “zero tolerance” workplace violence prevention policy, according to The Executive Employer Surveyfrom labor law firm Littler Mendelson.

The survey found that 40 percent of employers have developed an emergency response plan and a pre-employment screening process. Thirty-eight percent have conducted employee training sessions about recognizing and responding to a potentially violent situation; 33 percent have performed a safety and security audit; and 28 percent have conducted active shooter response training.

Eleven percent of employers responding to the survey say they have taken no action because violence is not considered an issue at their workplace, and another one percent have not acted for fear of violating disability or discrimination laws.