Depending on whether you are shipping dangerous goods by road (ADR), rail (RID), sea (IMDG Code) or air (IATA-DGR), there are different requirements and regulations. In air transport (IATA-DGR), the requirements are very strict and you must complete a refresher training every 24 months. The ADR, RID and the IMDG Code prescribe training courses at regular intervals. As these rules and regulations are updated every 24 months, it is also advisable to take part in dangerous goods training every 2 years.