Vaccine transport in dry ice
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Vaccine transport in dry ice
What are the procedures for carrying dry ice onboard aircraft? Can dangerous levels of carbon dioxide be detected?
https://www.nytimes.com/2020/12/10/b...ant=0_identity
For its vaccine, Pfizer designed special cooler containers that can be stuffed with dry ice, which is solid carbon dioxide. But aviation authorities limit how much dry ice can be carried on planes because it turns to gas, making the air potentially toxic for pilots and crews.
https://www.nytimes.com/2020/12/10/b...ant=0_identity
There are laid down limits for CO2 carriage. We carry a lot of it in the freight business for all sorts of applications. We have been using these new type containers on some specific routes for some time. Their design markedly reduces the sublimation rate (solid to gas) so the amount of CO2 we can carry if these containers are used has been increased approx 3 fold. We don’t have CO2 detection, relying on the integrity of containers and packaging.
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deltahotel,
dry ice sublimates, the containers and packaging are designed to allow the resultant gas to dissipate, if they were airtight causing gas build-up, this wouldn't make for a happy ending.
dry ice sublimates, the containers and packaging are designed to allow the resultant gas to dissipate, if they were airtight causing gas build-up, this wouldn't make for a happy ending.
TBH I don’t know all the technical details other than they work and allow carriage of a lot more dry ice. This all shows how little attention I’ve given to DG training in the past but happily I’m doing my annual refresher this week so will try to get some answers on Thursday! I do know that they have a lower sublimation rate which is presumably a comment on the level of insulation. This lower sublimation rate allows the gas to dissipate safely. I think.
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Carbon Dioxide risk to flight deck crew
What are the procedures for carrying dry ice on-board commercial aircraft? Is there a method of detecting dangerous levels of carbon dioxide?
From the New York Times article; https://www.nytimes.com/2020/12/10/b...ant=0_identity
I posted this thread some three hours ago and it was deleted. Not just moved which possibly i could understand, but completely deleted.
This time I have screen shot the post. This is a relevant flight safety issue and deserves consideration.
For its vaccine, Pfizer designed special cooler containers that can be stuffed with dry ice, which is solid carbon dioxide. But aviation authorities limit how much dry ice can be carried on planes because it turns to gas, making the air potentially toxic for pilots and crews.
I posted this thread some three hours ago and it was deleted. Not just moved which possibly i could understand, but completely deleted.
This time I have screen shot the post. This is a relevant flight safety issue and deserves consideration.
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Coronavirus vaccine transport
Airlines Gear Up to Transport Vaccines That Could Revive Travel[
Carbon Dioxide levels on commercial aircraft have to be an issue worth discussing on PPRuNe or is anything Covid related now censored?
OPENDOOR. Discuss away - there’ll be someone along to answer your questions.
Currently regs are in place to allow carriage of dry ice in appropriate packaging and quantities that will allow the sublimated gas to disperse safely. The amount is reduced eg if we only have one pack working. With this new packaging the sublimation rate is less, so more dry ice can be carried. It’s actually not that new - we’ve been using similar packaging for a while now, mainly for carriage of medical stuff to specific destinations. These regs have been in place for a very long time. One of my NOTOC checks is quantity of dry ice carried.
We don’t use detectors, good question though. But neither do we have detectors for any of the other DG that we carry eg acids, alkalis, solvents. Regs for packaging of DG are really stringent and rigorously applied.
Currently regs are in place to allow carriage of dry ice in appropriate packaging and quantities that will allow the sublimated gas to disperse safely. The amount is reduced eg if we only have one pack working. With this new packaging the sublimation rate is less, so more dry ice can be carried. It’s actually not that new - we’ve been using similar packaging for a while now, mainly for carriage of medical stuff to specific destinations. These regs have been in place for a very long time. One of my NOTOC checks is quantity of dry ice carried.
We don’t use detectors, good question though. But neither do we have detectors for any of the other DG that we carry eg acids, alkalis, solvents. Regs for packaging of DG are really stringent and rigorously applied.
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Sublimation rate should not exceed ventilation rate of the pack system hence the limitation on the carriage of the amount of dry ice (this should prevent CO2 buildup). Procedures in place for different air conditioning and pressurisation failures.
https://www.faa.gov/other_visit/avia.../SAFO20017.pdf
https://www.faa.gov/other_visit/avia.../SAFO20017.pdf
Last edited by marsipulami; 15th Dec 2020 at 17:56. Reason: Add.
We carry a fair amount of dry ice in the cabin, for keeping things like ice cream frozen. Also if the galley chillers are on the blink.
On many passenger aircraft that I know, the air comes into the cabin, some of it is recirculated and some of it goes through the hold and then is exhausted without passing back into the cabin. On that basis, you are very unlikely to be asphyxiated by sublimed CO2 from the hold, any more than you are from that produced by the respiration of your fellow passengers.
There are certain requirements, one of which being you have to be careful when packing not to have livestock and dry ice in the same compartment, for obvious reasons. All that said, given that CO2 is not classified as toxic, and is in widespread use almost everywhere, I’d worry more about all the other things that could float around inside an aeroplane...
On many passenger aircraft that I know, the air comes into the cabin, some of it is recirculated and some of it goes through the hold and then is exhausted without passing back into the cabin. On that basis, you are very unlikely to be asphyxiated by sublimed CO2 from the hold, any more than you are from that produced by the respiration of your fellow passengers.
There are certain requirements, one of which being you have to be careful when packing not to have livestock and dry ice in the same compartment, for obvious reasons. All that said, given that CO2 is not classified as toxic, and is in widespread use almost everywhere, I’d worry more about all the other things that could float around inside an aeroplane...
As a caver i've come across carbon dioxide a few times. Levels have been as high a 5.1%! At 3% one breathes very heavily which is an excellent warning. From memory Australian workplace regulations (coal mines) dictated 0.5% as a maximum. CO2 detectors should not be too hard to organise. Aircrew must all have suitable O2 readily available for the duration of flight.
Initially vaccines will be on vaccine only freighters. Later on they may be with mixed cargo but no animals. Further down the track even on regular pax flight. In the event of a CO2 build-up a depressurise and divert emergency procedure would apply.
Initially vaccines will be on vaccine only freighters. Later on they may be with mixed cargo but no animals. Further down the track even on regular pax flight. In the event of a CO2 build-up a depressurise and divert emergency procedure would apply.
I’ll take a wild stab at a 777-200 cabin being ~1000m3. 0.5% of that is 5m3 which is equivalent to ~10kg of CO2 at STP, should you want to get to that concentration. This assumes it all stays in cabin while the concentration is building up, which with the packs and/or fans running is highly unlikely. To get to a point where you’d physically notice it, you’d need 5-10x as much, which is a s@%# load of dry ice!
In other words, yes, we are aware of CO2 and it appears in Dangerous Goods legislation and is subject to the constraints thereof, but no, it’s not a major source of death in the sky. Carbon monoxide, OTOH...
In other words, yes, we are aware of CO2 and it appears in Dangerous Goods legislation and is subject to the constraints thereof, but no, it’s not a major source of death in the sky. Carbon monoxide, OTOH...
Fullwings beat me to the maths, thank you. So some numbers. Normal packaging is based on a sublimation rate of 2%/hr, this allows our 75s 2T of dry ice on the main deck. Our current enhanced packaging is based on 1%/hr, allowing 4T on the main deck. This new packaging allows 13T. Alongside this there are rules about other freight nearby, primarily animals. (All figures rounded).
Be assured, aircrew always have 100% O2 available.
There is no good reason to have a flight as vaccine only. You can get loads of doses in a very small space and I believe our first vaccine flights are mixed cargo. For us it’s just another pallet or bin of freight to be packed in a certain way.
As said before there are no plans for CO2 monitors, though I am happy to ask the question on Thursday.
With the exception of a main cargo deck fire there are no QRH drills requiring decompression. If I felt that my performance was impaired due CO2, smoke and fumes would be the place to start.
The biggest danger with CO2 would be Fullwings handling it with the ice cream and getting a cold burn. Ps Catering dry ice doesn’t count towards the totals above.
Be assured, aircrew always have 100% O2 available.
There is no good reason to have a flight as vaccine only. You can get loads of doses in a very small space and I believe our first vaccine flights are mixed cargo. For us it’s just another pallet or bin of freight to be packed in a certain way.
As said before there are no plans for CO2 monitors, though I am happy to ask the question on Thursday.
With the exception of a main cargo deck fire there are no QRH drills requiring decompression. If I felt that my performance was impaired due CO2, smoke and fumes would be the place to start.
The biggest danger with CO2 would be Fullwings handling it with the ice cream and getting a cold burn. Ps Catering dry ice doesn’t count towards the totals above.
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O2 for all crew for the full duration of the flight is NOT carried, O2 is carried sufficient to permit decent and travel to about 10000 ft In this case it will not be Oxygen that is the problem but CO2 which will still be present at lower altitude. You may find that you would not be aware performance is impaired. CO2 poisoning is a not very noticeable event leading to unconciousness and death. You not notice but some of the passengers may but not be able to do a thing about it.
Q Concentrations of more than 10% carbon dioxide may cause convulsions, coma, and death [1, 15]. CO2 levels of more than 30% act rapidly leading to loss of consciousness in seconds. Apr 4, 2017
Q Concentrations of more than 10% carbon dioxide may cause convulsions, coma, and death [1, 15]. CO2 levels of more than 30% act rapidly leading to loss of consciousness in seconds. Apr 4, 2017
Last edited by harrryw; 16th Dec 2020 at 06:57.
The biggest danger with CO2 would be Fullwings handling it with the ice cream and getting a cold burn.
Shocking!
For clarity and to try to pull some threads together.
This is not gaseous CO2 from a cylinder. This is solid dry ice which turns to gas (sublimes) at known rates depending on the packaging. It is already in packaging when it arrives at the ac. The ability of the ac air systems to change the air is known. All of this generates limits on the amount that can be carried. We have been doing this for years, it is known stuff and although it may sound new and scary it actually isn’t.
We’ve started moving vaccine around the world in mixed freight.
FWIW my 757 with 2 crew has sufficient O2 for 3 hours at 100% at 25000’.
I’ve deliberately confined myself to freight only ops as it’s 18+ years since I operated a pax ac.
Hope all of this helps, I’m not sure there’s much else to say on the matter. I hope that @OPENDOOR feels that questions have been answered.
For clarity and to try to pull some threads together.
This is not gaseous CO2 from a cylinder. This is solid dry ice which turns to gas (sublimes) at known rates depending on the packaging. It is already in packaging when it arrives at the ac. The ability of the ac air systems to change the air is known. All of this generates limits on the amount that can be carried. We have been doing this for years, it is known stuff and although it may sound new and scary it actually isn’t.
We’ve started moving vaccine around the world in mixed freight.
FWIW my 757 with 2 crew has sufficient O2 for 3 hours at 100% at 25000’.
I’ve deliberately confined myself to freight only ops as it’s 18+ years since I operated a pax ac.
Hope all of this helps, I’m not sure there’s much else to say on the matter. I hope that @OPENDOOR feels that questions have been answered.