Gas permeable materials improve safety of life saving appliances.

Spray-hoods are additional items of life jackets. They are very effective in reducing water contact of the breathing openings when victims have to stay in rough seas without boat or life raft. A life raft is also a very important life saving device. But both have a system problem. They consist of a more or less encapsulated space in which humans have to breathe. To ensure a sufficient amount of oxygen and to reduce the amount of carbon dioxide, spray-hoods have ventilation openings which reduce the efficiency of this equipment, but most of the life rafts have no ventilation. In a series of tests we used a new gas permeable material for the hoods. This reduced the flooding of victims to a very little amount, while O2 and CO2 stayed at acceptable levels. Our experiments with conventional rafts showed that the O2 level went down to less than 15% within 50 minutes while CO2 went up to 6%. These are dangerous levels. The canopy of some of the life rafts were modified with the above mentioned new gas permeable material. Identical rafts were used in comparative trials. The tests showed positive results for the new material. The minimum O2 level stayed at 20.2% and CO2 reached a maximum of 0.52%. The results prove that this material can lead to a much safer rescue system than the systems used so far.