Effects of electric current passing through the human body; factors normally providing protection from electric shock; lightning hazards; earthing of power supplies; earthing of electrical enclosures; the need for bonding; protection of personnel: RCDs, effects of electric and magnetic fields and electromagnetic radiation; electrosurgical hazards; electrical fires and their investigation; electrical discharges; electrical safety and the law; hazardous areas and their classification; gas grouping; temperature classification; Exd, Exi, Exe, Exn, Exp, Exs methods of protection; dust ignition proof; cabling and terminations for hazardous atmospheres; certification, marking, quality control and maintenance requirements for hazardous atmospheres.