fsw (9 msw), for further periods on oxygen according to the schedule. Air breaks of 5 minutes are taken at the end of each 30 minutes of oxygen breathing. Saturation systems emergency gas supply During decompression from saturation, a pressure will be reached where raising the oxygen concentration further would cause an unacceptable fire hazard, while keeping it at an acceptable level for fire risk would be inefficient for decompression. BIBS supply of breathing gas with higher oxygen content than the chamber atmosphere can solve this problem. If the atmosphere in a saturation habitat is contaminated, the inhabitants can use the available BIBS masks during the emergency and be supplied with non-contaminated breathing gas until the problem has been solved. Submarine emergency gas supply Submarine BIBS systems are intended to provide the crew with diving quality air or nitrox breathing gas in an emergency escape situation where the interior may be partly or completely flooded, and may be at a significantly higher than atmospheric pressure. The supply gas is provided from a high pressure storage bank at a pressure automatically compensated for depth and is distributed around the vessel to points where the breathing units can be connected as required. References Submarine rescue equipment Diving support equipment Diving medicine Decompression equipment