After a nuclear accident leading to an important radionuclide deposition, the responsible authorities are faced to the question of complying with intervention levels. These regulations may be expressed as mass activities in foodstuffs, or individual doses for the populations. A situation of acute caesium 137 contamination of the environment was played in 1993 during a French and Russian joint crisis exercise. In answering the questions from the administration, the experts examined the conditions allowing agricultural practices 1) according to a set of intervention levels in foodstuffs, and 2) how that was compatible with a recommendation relative to an individual dose for the populations of 1 mSv/y, although this limit is applicable in normal conditions and is not intended for post-accidental situations.