Oxygen cells remain largely unavailable to the dive community due to production being switched to deliveries for medical orders.
Oxygen sensors, or "cells," which are used in rebreathers have a limited shelf life and need to be replaced every 12 to 18 months. However, new ones are currently not available to the dive community.
In the United Kingdom, oxygen cell manufacturers have been mandated by the UK government to supply cells to the medical industry, leaving the dive community with back orders.
At this juncture, it is not known when cells will become available for divers, but Martin Parker, managing director of AP Diving, which manufactures the Inspiration line of closed circuit rebreathers, stated in a response posted on a mailing list: "Contact the factory, put your name on the order list, we won't take payment, and you get the opportunity to refuse the sensors when we contact you."
Policies of other manufacturers are not yet known; we have sought comment and are awaiting responses.
Resist the temptation!
Some owners of closed circuit rebreathers with sensors being near or past their expiration date may be tempted to continue to go diving on their units. Please resist the temptation. Using cells that have exceeded their safe-usage date increases the likelihood of having an incident or even suffering a fatality.
Several cases, including some fatalities, which we have reviewed over the years were attributed to the use of expired cells in rebreathers, leading to misreadings of oxygen partial pressure.