Before entering

Before entering a tank or any other enclosed space, the following must as a minimum be in place.

  1. A work certificate must have been issued in accordance with order no. 372 issued by the Danish Working Environment Authority, “regulations on work on board vessels with tanks for oil, etc.” Annex 1 in this orientation can be used instead of the work certificate. A similar form with the same information and signature can be used.
  2. A new measurement of the atmosphere in the tank/space must be made immediately before the DMA’s inspection (max. ½ hour). Before measuring the atmosphere, the ventilation must have been stopped for ten minutes. The ventilation is re-started after the measurement. If there is a suspicion that the atmosphere in the tank/space is changed (for example, in connection with the moving of cargo or ballast, changes in trim, etc.), the inspection must be stopped and a new measurement is to be carried out.
  3. The measurement must be made by a competent person or by a recognized company, and measurements must be made for oxygen, explosion danger and toxic substances
  4. During the entire inspection, a man must be posted at the hatch at the entrance to the tank/space. The “hatch man” must be provided with a means of communication for alarming and he must have been instructed about what to do in case of an accident. Any equipment for evacuation must have been prepared and made ready for immediate use. The communication between the “hatch man” and the surveyor must have been arranged
  5. The mechanical ventilation must continue during the inspection. However, deviations can be made from this requirement for small tanks in accordance with the surveyor’s estimate. There must be awareness that, though the mechanical ventilation is turned on, there can be pockets in spaces/tanks that are not ventilated
  6. If there is any doubt whether the space is a tank/enclosed space, what is decisive is that the DMA’s surveyor considers it a tank/enclosed space.
  7. If the DMA surveyor is in doubt whether the atmosphere in the tank/space is secure, about the quality of the measurements or the competence of the person who has carried out the measurement, the surveyor must postpone the inspection.

Regulations and guidelines

  • Order no. 372 issued by the Danish Working Environment Authority, “Regulations on work on board vessels with tanks for oil, etc.”.
  • IMO Resolution A.1050 (27) Revised Recommendations for entering enclosed spaces aboard ships.

We hereby stress that the DMA surveyors have been instructed not to start inspecting tanks/enclosed spaces if the above-mentioned minimum guidelines are not observed


Annex 1 - Inspection of enclosed spaces / tanks