International Atomic Energy Agency (IAEA)
Emergency Worker Turn-back Dose Guidance 1

Personal dose equivalent not to be exceeded unless approved by Incident Commander


50 mSv 1

Actions to avert a large collective dose, such as:

  • Environmental sample collection and analysis for environmental monitoring of populated areas;
  • Localized decontamination if required to protect the public

500 mSv 1 2 3

Actions to prevent severe health effects or injuries, such as:

  • Evacuation/protection of the public;
  • Environmental monitoring of populated areas to identify where evacuation, sheltering, or food restrictions are warranted;
  • Rescue from potential threats of serious injury;
  • Immediate treatment of serious injuries;
  • Urgent decontamination of people.

Actions to prevent the development of catastrophic conditions, such as:

  • Prevention or mitigation of fires, etc.;
  • Apprehension of terrorist suspects.

1000 mSv 1 2 3 4

Lifesaving actions, such as:

  • Rescue from immediate threats to life;
  • Provision of first aid for life-threatening injuries;
  • Prevention/mitigation of conditions that could be life-threatening.

1 This dose guidance is set at levels that will allow completion of tasks and return to base without exceeding international guidance levels. Emergency worker dose level guidance values are expressed as an integrated external dose and it is assumed that all necessary precautions are taken to prevent internal exposure. The guidance is applicable for the entire time of the emergency.

2 Workers shall be volunteers and be provided with information on the potential health consequences of exposure to allow them to make an informed decision. For example: 3000 mSv exposure could be life-threatening, 500-1000 mSv can result in short-term vomiting, reduction in sperm count, and an increase in the chance (risk) of development of cancer from the normal rate of about 25% to about 30%. Exposure to a dose of 100 mSv will not result in any short-term effects, but will result in a small increase (about 0.5%) for the risk of development of fatal cancer.

3 Every effort should be made to keep doses below this dose while performing lifesaving actions.

4 In principle, there are no recommended dose restrictions for rescuers performing lifesaving activities. However, this applies if, and ONLY IF, the benefit to others clearly is more important than the rescuer's own risk.

Adapted from Manual for First Responders to a Radiological Emergency (PDF - 2.2 MB) (CTIF, IAEA, PAHO, WHO, October 2006, page 41)