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When we think of CO, we think of CO being produced in a fire. However there is a unexpected CO source we need to understand too: sometimes living organic matter produces CO. And people have died not knowing this. At first I thought that people telling me about CO production in living organic matter had mistaken CO2 for CO. But now I know I was wrong. CO CAN be produced next to CO2 ! And CO, being produced in this way, has also killed.

Hazardous Off-Gassing of Carbon Monoxide and Oxygen Depletion during Ocean Transportation of Wood Pellets

Five ocean vessels were investigated for the characterization and quantification of gaseous compounds emitted during ocean transportation of wood pellets in closed cargo hatches from Canada to Sweden. The study was initiated after a fatal accident with several injured during discharge in Sweden. The objective with the investigation was to better understand the off-gassing and issues related to workers' exposure. Air sampling was done during transport and immediately before discharge in the undisturbed headspace air above the wood pellets and in the staircase adjacent to each hatch. The samples were analyzed with Fourier transform infrared spectroscopy and direct reading instruments. The following compounds and ranges were detected in samples from the five ships: carbon monoxide (CO) 1460-14650 ppm, carbon dioxide (CO2) 2960-21570 ppm, methane 79.9-956 ppm, butane equivalents 63-842 ppm, ethylene 2-21.2 ppm, propylene 5.3-36 ppm, ethane 0-25 ppm and aldehydes 2.3-35 ppm. The oxygen levels were between 0.8 and 16.9%. The concentrations in the staircases were almost as high as in the cargo hatches, indicating a fairly free passage of air between the two spaces. A potentially dangerous atmosphere was reached within a week from loading. The conclusions are that ocean transportation of wood pellets in confined spaces may produce an oxygen deficient atmosphere and lethal levels of CO which may leak into adjacent access spaces. The dangerous combination of extremely high levels of CO and reduced oxygen produces a fast-acting toxic combination. Measurement of CO in combination with oxygen is essential prior to entry in spaces having air communication with cargo hatches of wood pellets. Forced ventilation of staircases prior to entry is necessary. Redesign, locking and labeling of access doors and the establishment of rigorous entry procedures and training of onboard crew as well as personnel boarding ocean vessels are also important.
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After having read the article above, I wrote the researcher the following email:.

"I was very pleased with your articles on CO formation by wood pellets. As a hazmat officer in the Amsterdam fire dept. (dangerous goods not only being my job but also my hobby) I always try to understand technical principles behind accidents.

Two years ago I received questions on the formation of dangerously large amounts of CO2 in onions during sea transport. I know that fresh, living organic (plant)matter like onions, being stored in the dark, breath like we do. In the dark they do not produce oxygen – and consume CO2 as they normally do in the light, using photosynthesis. In the dark they consume O2 and produce CO2. I sometimes heard people say that they did not produce CO2 but CO. I always took that for an error, thinking that people mixed up CO and CO2 , as is often done.

Having this opinion, I was puzzled by a ship accident that happened some years ago in Rotterdam. One man died and one man got severely injured on board of a sea vessel loaded with dry corn (grain). The ships hull turned out to be full of CO – and this CO did not come from an engine, nor was it brought in the ship on purpose for fumigation purposes. The riddle of where the CO came from, was never solved. I could not believe that the grain could have produced the CO itself. But now that I read your reports on CO formation from wood pellets, I think that the same principle might occur in other kinds of organic matter.

Could you perhaps give me your opinion on this? And do you perhaps have more reports, either from you or from other researchers – on (biological?) CO formation from organic matter?"

I hope the reseacher will answer my email. If he does, I will inform you too. There is a lot still to be learned about this phenomenon of CO formation in living organic matter!

Keep it safe out there,


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