Burned by chemical heat pack on deco - Scotland

[PfcAJ]

And you know how much it bothers me to agree with AJ.


iPhone. iTypo. iApologize.

 

[nadwidny]

I think argon is often used because it insulates better than air. I've heard suggestions that argon tanks should have different valves and regs so that a diver could no mistakenly put a breathing reg on an argon bottle, but I don't know how common that risk is.

It's not.

 

[Jack Hammer]

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 ...

Does that require having your underwear O2 cleaned?

You might want re-read what you posted (no offense intended). Damage to the pack is not the issue. The pack reaching 269*F is hot enough to quickly boil water and cause quite a serious burn. There have been several cases over the years of divers getting burned using air activated heat pads while diving. Using them while diving is a bad idea. [emoji2]

 

[archer1960]

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 ...

Does that require having your underwear O2 cleaned?

269F is plenty hot to produce that kind of burn with extended exposure time.

 

[Dhboner]

Hind sight being 20/20 I am not sure it is a good idea to dive with back pain that is so severe you feel you need a heat pack on your back during the actual dive. I remember considering using small chemical heat packs in my dry gloves in the winter, but was too worried about how the chemicals might behave at depth...guess I know now!

 

[scagrotto]

You might want re-read what you posted (no offense intended). Damage to the pack is not the issue.

It should be clear that I was was addressing chilly's question, which asked about damage. The original story makes it clear that the pads aren't damaged at pressures of nearly 6ATA. The abstract I linked offers another example showing that they work perfectly (or too) well at increased pressures, and provides some additional info about just how well they work under those particular conditions.

The pack reaching 269*F is hot enough to quickly boil water and cause quite a serious burn.

I'm guessing that almost everybody realizes that 269º is really hot and can cause burns. If somebody reads this thread and still can't figure out that using chemical heat pads under increased pressure is a bad idea I'll have a hard time mustering much sympathy if they hurt themselves.

 

[iamrushman]

thanks for posting this I'm using it to illustrate what happens in hyperbarics. i am always frightened that a patient will wear one of these in the chamber...i can't do a strip search on patients prior to insertion.

 

[elizagem]

I am new'ish to diving, is it safe to use a heat pack with a wetsuit above 30mt?

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[nadwidny]

I am new'ish to diving, is it safe to use a heat pack with a wetsuit above 30mt?

Just don't. There are a lot of better options than introducing an unknown kludge into the mix.

 

[Diver0001]

I am new'ish to diving, is it safe to use a heat pack with a wetsuit above 30mt?

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The sodium acetate ones (clear liquid with a little metal disc inside) are safe to use. They have a self-contained system that creates an exothermic chemical reaction but doesn't rely on a reaction with oxygen, and they're reusable. They reach peak temperatures of about 54C and won't get any hotter regardless of depth. Being that they are self contained, you could put them in a wetsuit if you wanted to.

R..