Update: Now I Have a Personal Carbon Monoxide Monitor/Tester

[DandyDon]

Being less than educated in the ways of CO contamination, forgive me if my question sounds silly.

If your reg were "contaminated" wouldn't it simply be solved by blowing a little "clean" air through it? Does CO adhere to all parts and stay for a long time?

TY! Good point. I was thinking of the instances that CO has been found along with other contaminants, but I didn't clarify that. CO can come from exhaust systems or can be produced within a compressor with lubrication problems. I'm not qualified to answer beyond that, but you're correct: CO is odorless and can be easily dispelled, which is part of the danger. One charter captain told me how he was saved from CO poisoning only because the Nitrox also contained oil contaminants that fouled his reg.

Does nitrox make a difference? Example: Your CO reading is X and you know that in standard air, you'll experience the listed symptoms in the chart after the given time because it deprives you of oxygen. I read that CO attaches to hemoglobin more readily than O2. However, if pure oxygen will flush out excess CO, wouldn't Nitrox slow/reduce the contamination?

If you got the recommended maximum number listed on that chart but you're diving with higher amounts of oxygen, wouldn't there be some degree of offset? I'm assuming those numbers all reflect CO readings in standard air. I wonder what the maximum allowable would be if they tested conditions in which greater percentages of o2 were present.

Somewhat I suppose. If you were diving 32% Nx, that's 50% richer in O2 some there could be some offsetting benefit, but not enough to get me to dive a tank with CO contamination. Notice in the above mentioned story that the captain found CO and oil contaminants in his Nx mix. Some weeks later, a Texas tourist and local DM were killed and others injured by foul Nx from that same Roatan compressor.

Lastly, don't misinterpret this post....I clearly see the benefits of testing/monitoring. Just using this to get learned. ;-)

Sure, thanks for pointing out the shortcoming in my previous post.

 

[Flfiremedic]

Based on work experience, I've checked SCBA tanks filled locally in an African country...found traces of H2S. A "4 Gas Meter" might be a better choice. Reads LELs, O2, CO, and H2S.

 

[DandyDon]

I am certainly interested in the ongoing threads about the Maldives accident that claimed one life and injured nine severely with CO contamination - more than ruining a dream vacation for all, but that is certainly not a one-time-deal. DAN admits that many "drowning deaths" are not well investigated. Two were killed in Roatan three years ago at a popular resort in all too similar circumstances and cover-up strangely supported by vocal members here on SB. "It's not what you know; it's who you know." The DAN annual report should be out any day now and I hope it includes information promised by the resort but never released; if it was in a previous report, I missed it. DAN also admits that they do not get reports on all deaths. News on scuba deaths at popular dive destinations outside of the US are very often suppressed to avoid hurting tourist business.

My monitor is on the way to Utila Is Honduras with my Tech Inst today. I'll look forward to his reports.

 

[Dadvocate]

I did a quick read of the links, thanks, Don! Is this device something that could be held to a tank with air running, or is it best used to check if the environment where the tanks are filled is at risk?

Cheers!

 

[DandyDon]

I did a quick read of the links, thanks, Don! Is this device something that could be held to a tank with air running, or is it best used to check if the environment where the tanks are filled is at risk?

Cheers!

How about all three...?

I understand it could be used with a cracked tank valve, but take 2 minutes - much longer than say a Nitrox tester, and longer than I want to leave a tank hissing. Turn it on, drop it in a plastic bag, squeeze air out of bag, fill sufficiently with tank air that it's surrounded, close bag and wait two minutes.

And inspect the compressor. You have that right; leave if they don't like the idea.

 

[DandyDon]

This has been mentioned before, but not here: Even among the operators who do send in quarterly samples for testing - 3% fail!

Excerpted from http://co-cop.com/danarticle.htm

To get a more representative reading on how frequently air samples from dive centers fail on the CO limit, we contacted some of the major air testing facilities and got a different story. In fact, sources at one major laboratory, TRI Environmental, report that 3 to 5 percent of the air samples tested exceeded the 10-ppm limit. TRI tests between 1,000 and 2,000 air samples monthly.

Another major testing lab, Lawrence Factor, shares similar results. "I probably test about 100 samples a day," reported Bob Laughlin, Director of Laboratory Services at Lawrence Factor. "Of those, about 10 contain CO, and maybe three will be over the limit. And, typically we're not splitting hairs. Those that are over the limit aren't just a little over, they are usually grossly over the limit - maybe 30 to 40 ppm. In fact, I have two right here on my desk today. One is 45 ppm and the other is 50 ppm."

It should be noted that the data on CO-laden air comes not from the testing of individual cylinders, but from periodic testing of the air produced by compressors at air stations around the country. One bad air station could result in untold numbers of individual cylinders contaminated with CO. Most dive centers have their air verified quarterly. For those operating in the state of Florida, it's a legal requirement.

 

[mblake]

Ok I like the Pocket CO 300, is there a nitrox/co combination portable meter?
Since I understand I should check both in my future undeveloped country dives...
-Mike

 

[DandyDon]

Ok I like the Pocket CO 300, is there a nitrox/co combination portable meter?
Since I understand I should check both in my future undeveloped country dives...
-Mike

Not that I am aware of.

I was a little disappointed that I couldn't get the other CO tester I found, since I found it so much cheaper mostly - but that was an artificial clearance price, the cartridges had to be replaced every few tanks at about $1/tank overall, and did not give an accurate reading.

It did take me a while to decide that this $140 tester combined with a 24/7 monitor was a worthy idea, but I like the user replaceable battery, user calibration, accuracy from 5-500 ppm, 24/7 protection while traveling in strange environments, etc.

If testing every tank of Nitrox is a good idea - and it is, then checking every tank for the most common poison must be a good idea, IMO.

 

[mrlipis]

Great thread Don, thanks for the leg work. I hope you are on a commission from this company.

Does nitrox make a difference? Example: Your CO reading is X and you know that in standard air, you'll experience the listed symptoms in the chart after the given time because it deprives you of oxygen. I read that CO attaches to hemoglobin more readily than O2. However, if pure oxygen will flush out excess CO, wouldn't Nitrox slow/reduce the contamination?

If you got the recommended maximum number listed on that chart but you're diving with higher amounts of oxygen, wouldn't there be some degree of offset? I'm assuming those numbers all reflect CO readings in standard air. I wonder what the maximum allowable would be if they tested conditions in which greater percentages of o2 were present.

While this might be true you have to understand exactly what is happening. As the CO attaches itself to the Hemoglobin and you are at depth, the PPO2 is also increased and your blood is moving enough oxygen through the system, do to the elevated PPO2 but as soon as you start to surface and the PPO2 is reduced. BLAMO... no oxygen in the system, the Hemoglobin is saturated with CO. Blackout.... Drown... The CO doesn't gas off like nitrogen. It is attached like super glue, and now the PPO2 is like a .3 and there arent' enough molecules to get the job done.

The first symptom, is a headache and that should be huge red flag. I believe all of the divers on the Baani experienced their problems upon surfacing.

In summary, while one might be getting enough O2 at depth while breathing a toxic mix of CO, as soon as they ascend to 1 1/2 ATA or 15 to 20 feet, it is all over, even with a EAN32. Heck you could get to the surface and still blackout.

I was diving in Roatan a few months back and while on a dive I noticed a strange taste in my mouth. My first thought was I had gotten something on my regulator, like lotion or something. But after the dive my wife complained of the same thing. Something was weird about that air and although there was no incident, I will never make an assumption again and if I even suspect something is different I will thumb it.

These threads have been VERY informative and I will have a CO tester before my next trip.

Bruce

 

[DandyDon]

Great thread Don, thanks for the leg work. I hope you are on a commission from this company.

Haha, nope! That would ruin my intent here anyway...

I was diving in Roatan a few months back and while on a dive I noticed a strange taste in my mouth. My first thought was I had gotten something on my regulator, like lotion or something. But after the dive my wife complained of the same thing. Something was weird about that air and although there was no incident, I will never make an assumption again and if I even suspect something is different I will thumb it.

Scary! CO has no taste or smell, but may accompany certain tastes and/or smells. So often we work at safety at every other angle, but take air for granted, not asking to look at the compressor, not checking for inline CO monitors, not doing anything but hopping it's safe.

I don't know that Honduras has any rules or enforcements like in the US on tank air quality? We'd like to think that they'll protect the guests as injuries are bad for business, but nothing public came out of the death of the DM and the Texas tourist who died with CO tank poisoning at Coco View three years ago and their business seems to be still going well. The big difference between the CCV deaths and the Maldives death, both with other injuries...

1. CCV promised a full disclosure, then started deleting information on their board with CCV fans defending them on this board, and none of the injured posting here. The one thread was eventually pulled.
   
2. Some of the Maldives survivors came onto SB to tell us their stories and continued to discuss it all with us.

These threads have been VERY informative and I will have a CO tester before my next trip.

Bruce

Good. I hope it turns out to be just good testing experience and peace of mind. If you ever do get a reading, I hope you'll post about it.