The Scottish Ambulance Service has created new specialist teams to deal with any major chemical, biological, nuclear or terrorist incidents.
Three special response teams (Sort) have been created in Edinburgh, Glasgow and Aberdeen.
Training has included clinical skills, risk assessment, forensic awareness and decontamination procedures.
Previously, only police and fire services had been able to gain access to the inner cordon of major incidents.
A £4.3m investment has been put into the Sort initiative over three years.
Additional training in water rescue techniques means that ambulance staff can now also take a key role during flooding incidents.
Scottish Ambulance Service chief executive Pauline Howie, said: "Our Sort personnel are highly trained so that they can provide best quality clinical treatment to patients at the scenes of major incidents.
"The ability to work inside the inner cordon alongside other emergency responders will result in quicker access to patients and a much higher level of clinical care and triage at the scene."
Health Secretary Nicola Sturgeon, who attended a demonstration by the ambulance service, said: "It is important that all emergency services in Scotland are prepared to deal with large scale, hazardous incidents wherever they occur."