Thousands of NSW health workers will walk off the job next month, demanding better security after a spike in violent attacks on staff.

The Health Services Union (HSU) says 22,000 paramedics, cleaners, administration staff and security guards are holding a four-hour strike on August 1, and there will be delays to routine services.

“We are not going to stop this campaign until such time as the government addresses the security within health services across the board,” HSU secretary Gerard Hayes said.

“We’ve seen too many people stabbed, too many people shot, too many people who are being spat upon or punched, too many people on workers comp, too many people getting PTSD because they went to work.

“It’s now time to take security within the health setting seriously and fundamentally changing what we’re currently seeing.”

The strike will not affect emergency patient treatment.

“All patients or potential patients within the ambulance area will always be looked after. In terms of any kind of emergency ambulance response, that would always occur,” he said.

“However, more routine matters would not be going forward during that period and ongoing we will be determining what other level of action could be required.

“It will slow the hospital system dramatically.”

The union is calling for at least 250 more guards to be stationed at facilities across the state.

“We want to change the security program to not be reactive, we want a proactive security program that is run by security specialists who have a training in health, who understand mental health, who understand drug addiction and drug abuse,” Mr Hayes said.

“We want to have a safe hospital system and that can only be done by the appropriately trained, the appropriately qualified and the appropriately resources numbers of security personnel in the health setting.

“We’re trying to get the government to get to a point to stop the violent in hospitals, resources appropriately, make the workplace safe.”

A total of 465 assaults were reported in hospitals across NSW last year, including a patient being stabbed and three nurses being attacked with scissors.