Carbon Monoxide suspected in incident with 12 children - UK

[Bubblesong]

I insisted on testing my Nitrox tanks before accepting them, two of them only had 2,000, instead of 3,000, so right there I was glad I didn't just accept them!

 

[DandyDon]

I live in NJ and found this reference that indicates atmospheric CO can range from 1 to almost 4 ppm - so having tanks test up to 3 ppm would not be surprising (or avoidable), would it?

https://www.google.com/url?sa=t&source=web&rct=j&url=http://www.njaqinow.net/App_Files/2012/Carbon%20Monoxide%202012.pdf&ved=0ahUKEwin-p-3i-LUAhULcj4KHQG7D1QQFggdMAA&usg=AFQjCNGqCw54UiPsj5ImNBKxNaSD2RfZPw

That is a lengthy article to appreciate fully, but I gather than the message is that the state has worked to clean up its air, and one could expect exposures of 1 to 4ppm. I think that range could be expected in most urban areas across the US.

Professional fill stations can filter their intake air to reduce CO levels before compression tho. How accepting you chose to be is a personal call.

 

[BRT]

That is a lengthy article to appreciate fully, but I gather than the message is that the state has worked to clean up its air, and one could expect exposures of 1 to 4ppm. I think that range could be expected in most urban areas across the US.

Professional fill stations can filter their intake air to reduce CO levels before compression tho. How accepting you chose to be is a personal call.

The filter after the compressor should be turning the CO into CO2.

 

[DandyDon]

The filter after the compressor should be turning the CO into CO2.

Color me corrected, thanks.

 

[BoltSnap]

What is your limit that throws up a red flag?

I believe that in the US, the limit is 10ppm and in the UK is 3ppm. I wouldn't use anything that has more than 3ppm especially if going deeper. I live in a part of the world where they don't even know about testing CO in their tanks and I am probably the only one in the whole country that has and uses CO tester. I have tested air in tanks that was >20ppm CO. I helped a fill station here to go down from 17ppm to 0 - 2ppm by simply having them install a long hose on their intake pipe and hanging it high enough to be away from the compressor fumes (it is a gas powered compressor) and by making them change their filter more frequently. I test EVERY single tank that comes from filling outside our dive center.

 

[RayfromTX]

The filter after the compressor should be turning the CO into CO2.

Yep, Hopcalite is our friend and it works well if maintained and fed really dry air so maintaining the desiccant in the filter is also critical. CO after the filter may also mean other nasties that we aren't testing for and excessive moisture.

 

[Patoux01]

I test EVERY single tank that comes from filling outside our dive center.

To be completely honest, I'd even test it if it were my own center and I were responsible for the compressor. Currently trying to buy a CO analyser as someone took a CO hit nearby, got saved by his buddy. If that happens to me, not so lucky, because there's no buddy.

You always think that kind of stuff happens only in far-away-land, like Mexico, Vanuatu, Whatever-remote-country, apparently not.

 

[sunshower]

Any suggestions on CO analyzers to get or avoid?

 

[2airishuman]

I live in NJ and found this reference that indicates atmospheric CO can range from 1 to almost 4 ppm - so having tanks test up to 3 ppm would not be surprising (or avoidable), would it?

As others have indicated, the hopcalite in the filter stack should remove CO whether its origin is baseline atmospheric levels, contamination at the compressor input, or partial combustion of compressor lubricants. Most of the CO problems show up when there is a CO source so concentrated that the filter media is rapidly exhausted, or when the filter stack isn't maintained in a reasonable way.

I've had a long talk with my air supplier. They are in a freestanding building with no loading dock, use a Rix, change filters regularly, send out air samples to a lab regularly, and have a technical diver who supervises the compressor operation. I don't test.

 

[Patoux01]

They seem to be hard-ish to find in Europe. In the US there's at least oxycheq that has one and cootwo (or monox), neither of which I could find in Europe.