Article 5
1. Save to the extent that point 2 of Annex IV allows other measures to be applied, the user shall apply the general principles and the appropriate containment and other protective measures set out in Annex IV corresponding to the class of the contained use, so as to keep workplace and environmental exposure to any GMMs to the lowest reasonably practicable level, and so that a high level of safety is ensured. 2. The assessment referred to in Article 4(2) and the containment and other protective measures applied shall be reviewed periodically, and forthwith if: (a) the containment measures applied are no longer adequate or the class assigned to the contained uses is no longer correct; or (b) there is reason to suspect that the assessment is no longer appropriate judged in the light of new scientific or technical knowledge.