Did Methane Contribute To The Hyperbaric Explosion on Fiday?

A comment from Steve Wood posted today on the blog states:

“The troubling part of this incident is that it was an explosion, and, at least based on press reports,there was not a fire that led to a structural failure (as in the 1996 Yamanachi Kosai fire in Japan).  Following a presentation on veterinary HBO at the UHMS meeting in Maui, a group of us were having a typical bar conversation, and during the discussion, we raised the potential risks of methane in veterinary chambers (the presenter had mentioned the use of HBO in treating GI-related issues in horses). Consider the explosive potential of a large methane release in an oxygen-pressurized (or air pressurized for that matter) chamber – the ignition energy is so low that even a very small static spark, much less than a steel-on-steel percussion spark, could trigger an explosive event.  Obviously, the jury is still out in this case, but I’d suspect that methane is a factor in this incident.”

Steve does bring up a great point with the Methane and LEL/UEL (Lower explosive levels and Upper explosive limits).  I spoke to a friend who happens to be an Arson and Explosives Investigator for the last 22 years in the L.A. County Sheriff’s Bomb Squad about this today and he agreed that even in normal non-hyperbaric conditions, the combination of 5 to 6% Methane, above 21% oxygen, a very small ignition source, and perfect conditions can cause an explosive event.  Now increase the amount of oxygen, seal it all up in a hyperbaric chamber, add double the amount of pressure and a huge spark and the result speaks for itself.  We are not saying this actually happened – but it is definitely a possibility and cannot be ruled out.

Here is some reference material on this subject: (If you are a safety director anywhere, this is great reference material to have around)

Avoiding Static Ignition Hazards in Chemical Operations


Investigation of Fire  & Explosion Accidents in the Chemical, Mining, and Fuel Industries (A manual, Kuchta)


Facts About Methane that are Important to Mine Safety

Gas Explosion Handbook (Combustion Properties of Fuel/Air mixtures)

As it stands, it may be quite some time before the details of what actually happened is released.

A couple of questions for the industry (Ron please post these questions on hyperbariclink.com as well if you do not mind)

1.  Does anyone remember exactly what happened in 2009?  The cause of the fire and death of two people?

2.  What caused the accident in 2009?  Where is the report from the investigating agency so that IDIOTS & WING-NUTS out there learn a little something before they make the same mistake again.

3.  Do animal chambers get some sort of FDA 510k pre-market notification?  The FDA regulates pet food, I could not find anything about HBO chambers for animals on their website.

4.  What are the manufacturing regulations for animal chambers?  PVHO stands for Pressure Vessel for HUMAN Occupancy, is there one for animals? PVAO? Catchy.

Looking forward to some great responses.


Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s