The scale for assessing and communicating accidents during radioactive material handling. INES was developed by the International Atomic Energy Agency and has been used since 1990 to assess nuclear power plant accidents. In 2006, the scale was extended to handle all radioactive sources. The scale considers three areas of impact: people and the environment, radiological barriers and defense-in-depth. It is divided into 7 levels, each accident classified in the next level is 10 times more severe. Levels 1—3 are called incidents, levels 4—7 are accidents. Level 1 is also referred to as an anomaly. Events without any safety significance are called deviations from the operating limits. They are classified below the scale and labelled 0.