Blog Archives

CNBA Oxygen Content Analysis

A recent International Marine Contractors Association (IMCA) safety flash (01/16) contains details of an incident where a commercial diver collapsed due to low oxygen content of what was believed to be air which was supplied to  him.   Fortunately this occurred on the surface and there was no long term impact.

This incident is a useful reminder of the importance of testing diving gas before use.

As most service divers should be aware, it is mandatory for testing of Compressed Natural Breathing Air (CNBA) used by AT divers to be completed using a FACTAIR F2235.  As part of this test, the oxygen content should also be tested using an Analox Oxygen Analyser and this forms part of  the FACTAIR F2235 kit.

The oxygen content is then recorded on the test form (either included with the kit or downloadable from the FACTAIR website) which needs to be sent to the Diving Standards Team (DST).

It is hoped that by the use of the FACTAIR F2235 and Analox Oxygen Analyser incidents like that above can be avoided by AT divers.



Updated FACTAIR F2235 Operating Manual

The manufacturer of the FACTAIR F2235 breathing gas testing device has just produced a revision to the manual which is now available to download from their website. The latest manual is dated March 2015 and previous versions should now be replaced.

Link –


Gas Testing with FACTAIR F2235

In order to comply with the regulations concerning testing of breathing gas used for sub aqua AT it is necessary to use the FACTAIR F2235 gas testing kit.  In order to bring together information relating to the demand process, support arrangements and the training process for this equipment, 2015DIN04-078 has just been published on the Defence Intranet .

[Updated May 2016 – The DIN is now incorporated into BRd 2806(5) as Annex K]