People are the weakest link in most safety chains. Hazardous areas are no exception and the IECEx International Certification System has introduced a Certification Scheme for Personnel Competence covering most aspects relevant to working with equipment in hazardous areas. This was developed at the request particularly of the oil and gas industry where contract workers need to be assessed for operating in many different parts of the world. From small beginnings, it is estimated that more than 50,000 individuals are likely to become certified within the scheme.