If your task is potentially hazardous for you and your work colleagues or others working nearby, you might need a permit to work. This should include a safety assessment with all dangers and safeguards mentioned and should be available at the worksite. Some activities that might involve a permit to work include but not limited to: welding, cutting and burning, storage of chemicals, storage of electrical energy, working in confined spaces, diving, working at height, working in trenches, working over water, working with hazardous, toxic, flammable, radioactive or explosive substances. Also any work on hazard detection, alarms and fire protection systems.