The SBX backpack system from Safeback is designed to pull and deliver oxygen from snow if the wearer is buried by an avalanche, thus increasing their survival time. A group of intrepid volunteers has now proven how well the system works.
The 2025/2026 ski season has seen a significant number of avalanches across the world. Since December, scores of people have lost their lives to the phenomenon in the European Alps, the Pyrenees, and mountain ranges in Japan, Utah and Colorado in the US. Annually, about 150-200 people die from avalanches, which occur when upper layers of snow become unstable and rush downhill at speeds of up to 190 mph (about 300 km/h).
When someone is buried beneath the snow from an avalanche, it's estimated that they have about 15 minutes to be rescued before their oxygen runs out and they asphyxiate. The SBX backpack extends that time to a theoretical 90 minutes by sucking oxygen out of the surrounding snow, which is porous, and delivering it through the straps of a backpack. The oxygen-delivery system also pushes carbon dioxide away from the breather's face, dealing with two problems at once.
The system, which is detailed in the following video, is activated with a pull cord, and operates using six Energizer Ultimate Lithium batteries, which the makers selected for their ability to operate at extremely low temperatures.
To test the SBX system, an international group of researchers buried 24 volunteers face-down under at least 50 cm (about 20 inches) of snow. Half of them were buried with an activated SBX system and half weren't.
All participants wore devices to monitor their Spo2 levels, a measurement of the amount of oxygen-saturated hemoglobin in the blood. The reading is generally a mark of how well oxygen is traveling from the lungs into the bloodstream, and levels below 90% indicate hypoxia – a lack of sufficient oxygen. Readings below 80% can rapidly cause people to become confused or even lead to organ damage if not corrected in a reasonable amount of time.
For testing purposes, the team defined an adverse event as someone's Spo2 levels falling below 80%.
The team found that those using the SBX backpack stayed buried for a median time of 35 minutes with no adverse events, while those without the backpacks stayed buried for a median time of 6.4 minutes and reported seven events.
The results of those tests were published in the Journal of the American Medical Association and, while they certainly showed the effectiveness of the SBX system, they also drew the attention of other researchers. In a letter to the publication, a group of three French scientists specializing in mountain rescue in the French Alps took issue with a few parts of the study.
First, they said that in real-world conditions, someone who had just been buried under snow would have much higher respiration rates than those undergoing a voluntary burial in a highly monitored and safe environment. Those breathing rates could deplete oxygen much faster than in the tests, they argued. They also said that snow density can play a major role in oxygen permeability and that the device needs to be tested in a broader range of conditions, an assertion echoed by the original research team as well.
While the researchers didn't disparage the use of the backpack as a safety device, they did say that they felt devices such as airbags and avalanche transponders should also be considered by anyone engaging in winter sports where avalanches are likely.
Source: Safeback
