Burned by chemical heat pack on deco - Scotland

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Idiotic, plain & simple. There are electric suit heaters that are specifically designed for diving. Using a chemical pack is stupid. Being unaware of the reaction with suit gas is stupid. And if he had been aware, he should have used a separate inflation gas than his enriched deco mix.

It is pretty warm here at the moment (relatively speaking) so I wouldn't assume he did it entirely for the cold.
 
The diver, according to the article, was not wearing the heat patch for warmth but to add localized heat to help with a back issue.
 
Why was he using deco gas for his drysuit?[emoji47]


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It's difficult to determine what happened from the article, especially with lines like "he was using gas enriched with oxygen instead of the oxygen tank he normally uses..." Does this mean he would normally do this dive with and oxygen tank?

He could have been using something around EAN22, air, or even trimix (although he probably wouldn't put He into his drysuit). Either way the PPO2 at 160' would probably be enough to overheat the pack, and the article did seem to indicate that the problem occurred at max depth.
 
Why was he using deco gas for his drysuit?[emoji47]


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Some folks plug their 50% bottle into their suit.

My hypothesis is that he had a standard-issue backgas for that dive (air or 21/35) and the elevated ppo2 at depth is what caused the accelerated reaction. .21 on the surface vs 1.2 or whatever at depth is a pretty big difference.
 
And how much pressure will these packs withstand anyway?
AFAIK, there's nothing in them that would be damaged by reasonable pressures, and this incident certainly indicates that they work just fine at nearly 6 ATA. Here's an abstract from a study that exposed some to 3ATA and 95% O2 (conditions that could be encountered in a hyperbaric chamber). They reached a maximum temperature of 269ºF but weren't destroyed and didn't spontaneously ignite.

Air-activated chemical warming devices: effects of oxygen and pressure. - PubMed - NCBI

Perhaps you could get one to ignite with >95% fO2 at some pressure above 3ATA. It would make for a really exciting dive if you managed that inside your drysuit. Which makes me wonder ...
Some folks plug their 50% bottle into their suit.
Does that require having your underwear O2 cleaned?
 
This is a clear case of someone who didn't think it through.

Anyone who knows how heat pads work would know that some of them react with O2 and therefore get hotter as you go deeper.... DUUUHHHH

R..
 
He was using this for back pain and not as a heater.

Idiotic, plain & simple. There are electric suit heaters that are specifically designed for diving. Using a chemical pack is stupid. Being unaware of the reaction with suit gas is stupid. And if he had been aware, he should have used a separate inflation gas than his enriched deco mix.
 
I didn't mean to imply that he was using it for warmth. Only that it was stupid to use a chemical pack in the first place for whatever reason. Even if he was using air for his suit inflation, it would still be an elevated pO2 at depth. And you know how much it bothers me to agree with AJ.


iPhone. iTypo. iApologize.
 
https://www.shearwater.com/products/peregrine/

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