carbon monoxide in tanks - cozumel

[DandyDon]

I think your call to DAN is a good idea. Please let us know what you learn.

Also, I thought I posted a fairly good report on the actual incident a couple nights back. I have also completed a report with DAN and a report with PADI quality control. PADI has followed-up and seemed to have an established process in place to make sure the incident is researched. PADI already had any open case by the time I reported in, and my information was added to the existing case. DAN on the other hand has done a great job at making sure I've gotten any medical treatment I needed however, they have not even responded to my incident report. In contrast PADI emailed and called back within a couple hours assuring me they would obtain the dive shops reports of the incident and were already following up from a previous report that my information was being added with.

Yes indeed you did, and yeah yours was a first hand report. I am home on a faster connection now, but my mind is not up to speed. Sorry. :blush:

I fear that Padi and DAN will both give more of a show on this than pretense of actions on this as it was certainly not the first time nor will it be the last. YOU are in better position to get info and action from Padi and DAN since you were certainly a directly affected diver. Even tho you dismiss your injuries as minor, it was still traumatic I am sure. Hell, I bet the OP didn't even give you a refund. Ask for Dan Orr at DAN if you do as I am told he is more in the know than most staff.

Bottom-line. I'm sure the problem has now been corrected. However if 3-5% of tanks are CO loaded that means we as divers gets a bad tank on average every 25-33 dives. Portable tank testing for recreational divers must be advanced and educated just like testing Oxygen levels in Nitrox. My whole family dives (including my 10 year old son). Enforcing air standards at dive shops is great... but as divers we need the tools to insure are tanks are safe... and the industry groups should be leading the charge and seeing that as divers we are informed and making an air tester part of the basic dive equipment package should become a standard.

Also, when my 10 year old got certified (PADI) a year ago I participated with him. Bad air was hardly even talked about. If it smells bad or tastes bad get a new tank... That is a terrible standard as this incident has shown...

And I fear their idea of resolving the problem is only to move the truck, not change the position of the air intake much less install a CO monitor with cut off. Start asking to see those monitors at Ops and fill stations; see what you find.

Get one of these: Detect Carbon Monoxide I'll post a new thread in Basic Scuba this week about it and how to use it beyond the site instructions.

 

[augustib]

Occidental Grand used to be my preferred place to stay in Cozumel. I guess I am done with them until their in-house dive op takes the necessary steps to insure safe gas.

You may want to try the Iberostar Cozumel Resort (Just a little past the Occidental). The dive shop (Dressel Divers) does a good job... I took my 10 year old diving with me in October they provided a dive instructor for just the two of us during the whole week just to make sure he was safe since he is a new diver and doesn't have a lot of dives. Also the shop has only dive instructors. They didn't charge for this... but I did take care of them with the tips after I realized we were getting the white glove treatment and they wanted to insure my sons safety.

 

[shogan]

While it sounds like the CO poisoning would be accidental I think there is problems with the dive operation not figuring it out, or at least coming to the point of realizing they have a problem and stopping the dive. Then leaving the other divers down and boat gone it's a miracle there were not deaths.

I will be buying a CO detector and since the operation never came clean openly I will put them and the hotel on the do not use list.

$150 to stay alive it should be considered standard equipment for everyone.

 

[Doc Harry]

My BWT Gas Alert Extreme measures down to zero ppm. I test it with my breath, get readings anywhere from 1 to 4 pm. I pump and mix my own gas, and dive solo with the stuff, so I always measure every cylinder for CO.

I've asked this question before, how many "drownings" in scuba are actually the result of CO poisoning?

Calibrating the BWT unit (yellow) with 10 ppm calibration gas. The black unit is an Oxycheq O2 analyzer.

This an excellent analysis of the monitors presented. There are two major problems with the Pocket CO:

1.Calibration is very expensive, uses 100 ppm CO concentration, and takes too long.
2. Cross-sensitivity to other contaminants with this sensor is a real problem giving numerous false positives.

Another monitor worth looking at is the more expensive BW Tech Gas Alert Extreme which has a replaceable sensor ($200), however the display will not register until 3 ppm CO is present.
BW Technologies Gas Alert Extreme

It is too bad no one down there had a portable CO monitor to check the gas before the tanks mysteriously go missing or are emptied.

 

[redacted]

My BWT Gas Alert Extreme measures down to zero ppm. I test it with my breath, get readings anywhere from 1 to 4 pm. I pump and mix my own gas, and dive solo with the stuff, so I always measure every cylinder for CO.

I've asked this question before, how many "drownings" in scuba are actually the result of CO poisoning?

Calibrating the BWT unit (yellow) with 10 ppm calibration gas. The black unit is an Oxycheq O2 analyzer.

How often do you have to calibrate? What causes calibration to drift?

 

[swamp diver]

How often do you have to calibrate? What causes calibration to drift?

The BWT manufacturer recommends a minimum calibration interval of 180 days but I try and calibrate quarterly. As DocHarry mentions prior to each day of use one can 'bump' check the unit is responding to CO by just breathing gently into the sensor. Our body produces its own CO as a gaseous neurotransmitter so there will always be low levels in the breath of non-smokers. Otherwise one can use the same 10 ppm CO calibration gas to verify the calibration is accurate before a weekend of diving, but having sat for a month or two.

Drift is a long-term phenomena whereby the output of the sensor slowly declines over time. The electrodes in the electrochemcial sensor slowly become poisoned by small amounts of contaminants such as VOCs and sulfur compounds in the atmosphere. Since divers generally run VOC-free air over the sensor the process is delayed which prolongs its life. The manufacturer warranties the sensor for two years but with intermittent use and exposing the sensor to only clean air they will easily last four or five years.

 

[Ayisha]

So it sounds like the breath test can adequately replace the calibration/test kit? Is that true?

 

[swamp diver]

So it sounds like the breath test can adequately replace the calibration/test kit? Is that true?

No the breath test really is a very crude 'bump' or functional test which only ensures the sensor is responding that day, but an ideal daily bump test should be done with a known concentration of gas that is above the alarm set points. The known gas concentration is applied, the alarms are activated, and the final concentration is confirmed as accurate taking into account the sensor's tolerance range.

If for example the bump gas concentration is 10 ppm but the unit reads 7 ppm then a full calibration will be required to reestablish accuracy. The calibration process uses a calibration gas concentration which is known and verified against a reference standard usually provided by an organization such as NIST. Calibration reestablishes two reference points on a linearity curve, one for the zero point and the second for the calibration gas concentration typically at 10 ppm for dive gas applications.

As it is not possible to take a tank of calibration gas on the airplane to a dive resort one can blow into the unit to set off the alarms and verify daily function. Your local smoker's breath can easily set off a 3 ppm and 5 ppm low and high alarm.

 

[vladimir]

Hey fellow divers, Patti here with Analox Sensor Technology. This is an important issue in our industry and EVERY diver should seriously consider testing every fill unless it comes from a compressor equipped with a Carbon Monoxide monitor/alarm.

Analox Sensor Technology is driving a revolution in diver safety with the COClear compressor monitor. While shops currently test for CO quarterly, the COClear compressor monitor is a cost effective way for every shop and resort to ensure EVERY fill is COClear EVERY time. Look for the COClear window sticker at your local dive shop.

Analox recognizes the need for a portable CO monitor for the traveling diver. We have a unit in development so stay tuned.

Safe and Happy Diving!

I just want to echo the sentiments of a few other posters. I am not a huge fan of businesses jumping in with marketing messages, but in this case I think it was totally appropriate. One of the best things about Scubaboard is the opportunity to interface directly with manufacturers. I own an Analox nitrox analyzer, which is a quality product, and will buy a CO monitor as soon as you introduce it.

 

[suprane]

My BWT Gas Alert Extreme measures down to zero ppm. I test it with my breath, get readings anywhere from 1 to 4 pm. I pump and mix my own gas, and dive solo with the stuff, so I always measure every cylinder for CO.
Calibrating the BWT unit (yellow) with 10 ppm calibration gas. The black unit is an Oxycheq O2 analyzer.

Well! I just got off of the phone after speaking with a representative of CanarySense.com. They are an autherized retailer for BW Technologies analyzers. Here is what I have learned thus far:
1) Bw Technologies is a Canadian based subsidiary of Honeywell.
2) They recommend that you calibrate your unit with a 100 ppm CO gas (which they will gladly sell to you at a cost of $140).
3) Oh, and by-the-way, you will need a regulator to hook up to that bottle of calibration gas!... Uh, that's another $150!.... See where this is going yet? :depressed:
4) Now the analyzer itself will set you back $265. It is, however, calibrated at the time you receive it. So (as the rep was quick to point out!), you can deffer the cost of regulator and calibration gas for a "few months" if you so desire.... Bottom line: You will be out those costs eventually!
5) They have no adapters/methods for testing directly from a SCUBA tank. Therefore, you are relegated to purging gas into a Zip-lock bag, or what ever alternative method you can come up with!
6) When it is all said and done, you will have forked out $550 for the analyzer and equipment to calibrate it!

Wow!!! Seems steep to me! Surely there is a more "palatable" approach to this problem! Much as I am in favor of testing my tanks, I know I would have a hard time dropping that sort of money on a single gas analyzer!