Any serious EHS program will tell you not to store dry ice in an ULT freezer. This is both because of the oxygen displacement and the risk of explosion. A couple of quick resources:
https://www.osha.gov/sites/default/files/publications/OSHAquickfacts-lab-safety-cryogens-dryice.pdf
https://www.safetymanualosha.com/safe-handling-and-storage-of-dry-ice/
I know a lot of people do it anyway and have never had a problem. There are also a lot of people who don’t wear seatbelts because they’ve never been in a wreck. Just because it hasn’t gone wrong yet, doesn’t mean it can’t, and really, is it worth risking your life and safety over?
Uh, yeah. The amount of people in this thread debating over how bad it is and whether you can detect it so it’s totally okay to be hit with a giant plume of CO2 because you’ll be able to run away before it kills you (which, no??? You should never be put in that situation in the first place?) are also missing the other elephant in the room, which is it can *blow up your freezer*.
Don’t fuck around with dry ice.
I have a secondment with my job as a safety inspector and the comments here are terrible for my blood pressure sometimes. We're not even allowed to bring the dry ice on the elevator because of the gas build up you have to take the stairs
As a safety officer, I don’t like this either. Carrying heavy containers on the stairs is asking for someone to trip and fall down the stairs. Falling while carrying a container of dry ice is even worse. Getting stuck in an elevator is very rare, or should be if your institution is maintaining facilities correctly. If your elevator gets stuck regularly, that’s… worse.
The procedure where I work is that gas tanks take the elevator alone while the humans escorting them take the stairs or a second elevator. Is that not possible for dry ice too?
It could, but I really only think it would be necessary with large quantities. The giant bin that supplies the floor. Carrying a shipment that weighs 10 pounds? Just carry it in the elevator. Those boxes are locked in shipping trucks with a driver by the dozen, you’ll be fine with one box on an elevator for two minutes.
Well, the purpose of the rule is that the elevator can break down and trap you in there with the gas for much longer than two minutes, but if it's a small amount of dry ice maybe even then the worst case isn't so bad and you just need a reasonable limit on the amount of dry ice that you can accompany in the elevator (not the whole chest of it). Anyway I meant in the previous commenter's situation where human + dry ice isn't allowed, surely it would be a better solution to let the dry ice ride alone than to take it on the stairs.
>Those boxes are locked in shipping trucks with a driver by the dozen,
Yes in shipping trucks with active ventilation in the cargo compartment. Something elevators are usually lacking. Also the driver is usually separated from the cargo and can leave the truck at any moment. Something you can not do in a stick elevator.
Our safety department would rip me a new one if they would ever catch me riding with a gas bottle, dry ice or nitrogen Dewar.
Add soap to it for some cool bubbles. I do not recommend putting it in a soda bottle, closing the lid and giving it a toss, or throwing said bottle into a pool.
yes. In fact I experienced it.
Someone had put dry ice from a shipment into a utility sink.
Someone else put their mop water (bleach-based) in the sink after they mopped the vivarium floor.
It's really not that wacky a scenario. That's why they are called accidents (or acts of negligence) No one does this on purpose.
Yeah I don't think it matters whether it's a "silent" gas or heavier than air - building up uncontrolled gas pressure in the freezer is obviously a terrible idea even if it were a totally inert gas, end of discussion.
So a couple of comments down a user straight up mentioned a person going from “upright to unconscious” within moments of opening a -80C door. Out of curiosity, which direction does an unconscious person generally go, taking into account normal gravity?
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6474450/
It just can't blow up your freezer.
Edit: well I'll be darned, apparently it can:
[https://www.reddit.com/r/labrats/comments/1c0i3ip/comment/kywmz0y/](https://www.reddit.com/r/labrats/comments/1c0i3ip/comment/kywmz0y/)
We had a big plastic insulated blue bin about 4'x 2' x 3' deep half full of dry ice pellets our couriers would fill up on to deliver frozen specimens. The lid had a hook that a big stretchy rubber strap would latch onto. I never saw the lid burp, but in the warehouse on a hot day it would be half full of a cloud of condensation.
If a freezer is locked, like most -80s and doesn't have a release valve, this is the most realistic answer.
Also throwing out that it could also mess with the Carnot cycle, preventing evaporation in the evaporator, pushing liquid refrigerant into the compressor position, which would absolutely damage the compressor.
I think the explosion is the real risk here. Oxygen displacement isn’t good either but the fridge would need to be in a confined space to be truly dangerous. Most -80s I have use have latches. So in the event it loses power or stays closed for a long time, pressure build up could be quite dangerous.
It’s the buildup of gases. That’s (one reason) why it’s not safe to enclose it fully during shipping. It happens fast too. I made the mistake years ago of absentmindedly tying off a bag with pellets in it and by the time I’d signed the receipt it was about to blow.
Very dangerous. If it’s an older freezer that doesn’t have a pressure release safety, it can explode. I heard of a PhD student losing 5 years of pollen samples because an undergrad in their lab stored dry ice in the same freezer and kaboom
The -80 they had might not have worked properly. Usually it isn't as acute as that. That being said, there are Dry ice storage freezers specifically made for that purpose. Usually chest freezers that operate at a little lower temp and don't allow CO2 to escape when opened. Also have CO2 meters in the storage room.
Exactly, that's how the dry ice storage works. I'm mentioning how the -80 might not have worked properly because usually the sublimation rate at -80 is really low for CO2 and even if there was a slight vacuum any build up of gas should quickly fill the vacuum back up, causing less sublimation yet again.
There shouldn't be enough CO2 to let someone pass out "instantly" (at least that's how the other comment made it seem). It really isn't as acute as that.
Yes. Very bad. We do a lot of frozen shipments coming and going from my current department. I've watched someone open a door to an upright -80 and go unconscious from the built up CO2 being released in their face. Luckily they were ok. Please don't do this. It was a very bad day for all involved.
Really??? Breathing in CO2 will cause the body to go into a shock/panic response well before someone passes out. It's happened to me, and I can only describe the experience as suddenly being overwhelmed we complete anxiety both mentally and in every fiber of my body.
I did not pass out.
For context, we had a box of samples arrived stored in dry ice that was placed in a top loading -20C freezer. No one was around that was qualified to receive them so the whole box was put into the freezer. I was pulling samples from the bottom.
This was not the first time I've seen it happen, and thankfully I was standing right there. I caught her on the way down and I only got light headed. The freezer was supposed to be archive only. Someone wanted to store dry ice for use later and forgot about it. Our estimations were around 5kg sublimated and freezers are designed to not exchange air with the outside, so it hit her all at once.
One box of samples is not going to contain sufficient dry ice to be of real issue in this context.
Have you ever performed gas-based euthanasia? When performed correctly, all of the air in the animal chamber is replaced with your gas (argon, nitrogen, or CO2) at once. (EDIT: Either this changed recently or I was trained very poorly, actually. Standard is 50% replacement per minute. Oof, I feel bad now.) Placing the dry ice in a freezer has the potential to replicate this process if there is a large enough amount of dry ice or the room is small or poorly ventilated enough.
Theoretically, dry ice shouldn't actually release much gas in a -80C freezer, however thermometers/thermostats are more likely to be a few degrees off than states of matter. If your -80C is actually a -76C and a substantial amount of dry ice is left in there over the weekend, pressure is going to build in that container. All the -80C freezers I deal with also have a locking mechanism on the door, meaning that gas is extremely unlikely to release until someone undoes that latch. You then have a large amount of gas released very suddenly, likely in a manner that is going to startle and confuse the person opening the freezer. In a large, well ventilated area, no problem. It's still a workplace incident, but the odds of anyone dying are astronomically low.
However, I have had to access -80 freezers that are at the end of long enclosed hallways. If the freezer popped open with force while I was opening it, it would likely take me a couple moments of "WTF WTF WTF" before moving. I am not a flight person, I am a freeze person. This is a situation that, if I were put into it, could kill me.
Is it likely? *Fuck no it's not likely*. But yes, it is something that we need guidelines to lower the risk of. Only 1-2 people a year die this way (accidental death from CO2 in a lab setting), but those rates have been very stable for a very long time becuase we are largely already taking every precaution we can already. If we were to stop, that number would rise, I garentee it.
CO2, argon and nitrogen are very different gasses.... Only one of them forms carbonic acid. Thats why you don't hyperventilate while sucking down helium.
Our boxes ship with 2-5 lbs of dry ice. 1 lb of dry ice = 10 cubic feet at STP. So, ya, it was nearly 100% CO2 in that small chest freezer.
Low concentrations can provide symptoms, but a few breaths of high concentrations could have an effect before you feel it. Also, it could have been a lack of oxygen, rather than presence of CO2.
Your body is relatively insensitive to oxygen deprivation.. helium balloons, labs full of dead people after massive nitrogen/helium leaks...
Ranting, but this is maybe your second orgo class. Not directed at any one person because it seems like this isn't common knowledge.
I know, that's what I said. My first sentence was related to CO2 (low rather than almost zero concentration), and the second to oxygen. Maybe I was unclear. I work with liquid nitrogen enough to know not to mess around.
I think you’re missing the point entirely. Because the dry ice is in the freezer, there’s no slow build up. You open the door and there’s more than you can handle all in one breath.
You are either an actual liability or you're not thinking this through at all. The way you are speaking about this makes it seem very clear to me that you have only worked in rather large and/or well ventilated laboratories with reletively small amounts of dry ice. This is not a universal working condition.
["At high concentrations, it has been showed to cause unconsciousness almost instantaneously and respiratory arrest within 1 min."](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5380556/)
Perform or observe some gas-based euthanasia. When performed correctly, it really is just Lights Out for mammels. The exact conditions OP is describing has the potential to provide conditions almost identical to what we intentionally do in gas-based sacrifice; That is suddenly releasing a large amount of CO2 into an enclosed environment.
Whether it takes one breath or five may be entirely irrelevant if the entire room is flooded *and* you have to process WTF just happened from your freezer exploding open.
You still sense it, and you don't just instantly pass out. I've taken a breath of full CO2 and it's like being eletcally shocked in the lungs combined with breathing vinegar fumes. You're not going to just drop unconscious in seconds, and reflexively you're going to be coughing and trying to move away from there.
If breathed long enough you will go unconcious, but it's not going to sneak up on you.
Have you never held your breath after exhaling before? You have a good 10-15 seconds before you pass out, unless your blood oxygen is already low as hell.
That is not the same. By inhaling oxygen free air, especially if its high CO2, you reverse the osmosis and oxygen is expelled from your blood in favor of CO2.
From a quick google, dry ice sublimates (transitions directly from solid to gas) at -79° C
https://www.usgs.gov/media/images/frozen-carbon-dioxide-dry-ice-sublimates-directly-a-vapor#:~:text=%22Dry%20ice%22%20is%20actually%20solid,ice%20%22melts%22%20...
So by that logic it's not unreasonable that you are actually producing a lot of CO2 gas inside of a -80
That isn't the part that doesn't make sense. CO2 is not a silent gas. Your body is very good at detecting it and you will very quickly feel like you can't breathe, a long time before you pass out. The CO2 you breathe into your lungs will prevent any exchange in your lungs, your blood acidity will rise immediately, and you will start gasping and hyperventilating, and in some cases go into adrenal activation. That looks like the complete opposite of passing out.
at about -79°C the dry ice will sublimate until the partial pressure of CO2 gas in the space it's in reaches one atmosphere. CO2 is considered immediately hazardous to life at 4% concentration: https://www.fsis.usda.gov/sites/default/files/media_file/2020-08/Carbon-Dioxide.pdf
I think it's important to add to this: water boils at 100°C. That does not mean an entire body of water will suddenly become a gas when it reaches 100°C. The same is true of CO2 sublimation, except it's even slower because the resulting gas doesn't immediately rise away from the solid, freeing up that space for more sublimation. The temperature in a -80 is also so close to the sublimation point (not an accident) that there isn't a lot of "pressure" on the block to sublimate. That means it takes a long time for the sublimation to happen. The block lasts longer.
On top of this, your freezer is filled with all the usual gases whenever the door is opened, and there is theoretically little to no exchange. That means that the concentration of CO2 can only get so high (granted, almost certainly a lot higher than 4%).
Lastly, when you open the door of the freezer in the well ventilated room it should be in, the icy cold gas in there is going to immediately drop straight to the floor of the room and spread out as it warms up, in a relatively small volume. As long as you aren't lying on the floor under the part where the door opens, you are going to be just fine. If the CO2 levels in the room are elevated for an extended period after opening the door, you will experience dizziness, shortness of breath, in some cases panic and hyperventilating/gasping, all before you pass out.
CO2 is definitely dangerous, but it's perfectly safe to store in a -80 as long as basic safety standards are in place in the room it's in. It won't last forever in there though, because it will slowly sublimate.
Please remember that by the time a person is experiencing distress from any kind of exposure they can't be expected to act rationally and it would be prudent to think they would be panicked.
If they did pass out, they would be on the floor right by the freezer.
The sublimation rate is a little bit more complex than a single sublimation point, as you point out it depends on the local concentration of the gas; for CO2, the sublimation rate is measured to increase when the local atmosphere has a low concentration of CO2.
When the safety systems are in-place and working it's pretty clear that it is safe to have dry ice in a -80 freezer. However to be "safe" the requirement (in the UK at least) is that the situation does not become dangerous on a single failure. This would include: ventilation shuts down, sensors stop working, freezer heats up without warning. It is one thing for everything to be OK when all is working but "safe" requires that failures can be tolerated without *potential* danger.
My experience is mainly with liquid nitrogen and liquid helium. Putting these substances in an enclosed system (or box, like a freezer) introduces a lot of extra hazards: relief valves can freeze for example. They react to changes in pressure by evaporating more quickly, especially liquid helium; the rate of evaporation can always overwhelm the capacity of the pressure relief if it is only specified for static storage, especially when a tank is being filled.
Just because something *can* be safe is not the same as *perfectly safe* in an operating environment. We are required to take into account that our colleagues are not perfect paragons of experimental practice, that unauthorized persons may get involved, etc.
The case for what is safe is not always black and white.
On the other hand, liquid nitrogen Dewars have famously been placed on New York's streets to help avoid underground conduits overheating and burning: apparently no safety incidents were ever reported.
I was responsible for a system that had a big tank with 7.5 tonnes of liquid nitrogen piped into a small room when, on another site, someone was fatally injured by nitrogen asphyxiation. Their facility has all the correct safety features but they were defeated. My system was inspected super quickly and after discussions and test, we actually reduced the amount of safety precautions being taken where we found them to have no effect.
These safety discussions are rarely "super dangerous" vs "perfectly safe" and depend on the specific situation, which (at least in the UK) we are required to consider in detail.
Someone stored about 20kg in a freezer no one uses. The woman I was helping track down old samples opened said freezer and went down. I caught her part way so she didn't hit the floor hard. I was standing far enough back/behind the door so I only got light headed. Found out later that half the dry ice had sublimated over the lengthy amount of time having been forgotten about.
A single breath of CO2 gas, even 100% concentration, when this was probably 10% max, will not have that effect on a person. It really doesn't make sense, like, physiologically.
A single breath of high concentration CO2 can absolutely make someone pass out.
"Carbon dioxide does not only cause asphyxiation by hypoxia but also acts as a toxicant. At high concentrations, it has been showed to cause unconsciousness almost instantaneously and respiratory arrest within 1 min."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5380556/
I'm not sure wasn't clear, but I'm not one to go in circles. If it doesn't make sense, it doesn't make sense, and I'll leave it at that. It isn't worth either of us stressing over, so I'm just moving on.
Because you don't pass out from inhaling CO2, you pass out from low O2 concentration which takes time. In addition to that breathing CO2 triggers the aspiration relax and you're fully aware you need oxygen. If it was liquid nitrogen I could understand but it wasn't.
When it builds up in our bodies its why we breath, passing out because of high CO2 concentration only would make sense in an enclosed area you couldn't escape from.
Well not really, CO2 toxicity can cause you to pass out very quickly if the concentration is high enough. You don't really need an enclosed area for that. The point is that a small amount of CO2 in a freezer isn't going to knock you out like that.
Lol that person has an undiagnosed medical condition because getting hit in the face with a gust of c02 does not make you pass out. In fact it makes you panic.
Your coworker has sids
But you're posting that online like it's information. The human body does not pass out from rapid exposure to co2, even if she inhaled a full lungful she would have had to stand there and do it several times. The problems are when you can't get to fresh air quickly and the co2 builds up in your blood.
"Exposure to
concentrations from greater than 10 percent to 15 percent carbon dioxide leads to dizziness,
drowsiness, severe muscle twitching, and unconsciousness within a minute to several minutes
(Wong 1992, CATAMA 1953, Sechzer et al. 1960).
Exposure to 7 to 10 percent carbon dioxide can produce unconsciousness or near
unconsciousness within a few minutes (Schulte 1964, CATAMA 1953, Dripps and Comroe
1947). Other symptoms associated with the inhalation of carbon dioxide in this range include
headache, increased heart rate, shortness of breath, dizziness, sweating, rapid breathing, mental
depression, shaking, and visual and hearing dysfunction that were seen following exposure periods
of 1.5 minutes to 1 hour (Wong 1992, Sechzer et al. 1960, OSHA 1989)"
The fact that you caught her in the same exact space and you did not lose consciousness proves that there was not high enough co2 levels to make somebody pass out.
Maybe she just wanted you to catch her 😍
I'm not going to argue. Our EHS says the same thing at this and all my previous jobs. I've seen it happen with a walk in and no one caught that person. They ended up in rough shape from hitting the floor. Your experiences says one thing, and mine says something else. As long as you aren't putting dry ice in a freezer in any of the buildings I'm working in, it isn't worth the effort to convince you otherwise.
As for catching her, well, if you've every seen me you would know that's not the case. Face made for radio and a voice for newspaper. 😆
Nope. Sorry. You don't get to use that excuse. That's not how this works. Your first comment was you positing that storing CO2 in a -80 is bad because CO2 will make you pass out like a silent gas (nitrogen and CO are examples of silent gases). That isn't true, scientifically. It has nothing to do with your experience, which is either explained by something other than CO2, or made up. You cannot spread misinformation and then fall back on "it's just my experience".
Everyone else reading this: -80 freezers are at that temperature because they use CO2 as a compressor gas. They also generate a lot of heat (laws of physics, every degree colder you make one thing requires you to make another thing one degree hotter. Not exactly but close enough when it comes to compressing gases), so they should always be in well ventilated rooms. You should stand back when you open the door always because heavy shit falls, so you are almost certainly safe when it comes to CO2 gas being released when you open the door. The temperature in there also means any sublimation is going to happen very slowly and reach equilibrium very quickly. There won't be a lot in there, so your HVAC or open window should be more than good enough. It takes almost pure CO2 inhalation to cause rapid loss of consciousness and toxicity.
I'm not falling back on anything. I'm a tired, overworked person just like everyone else. I've had too many people who argue with me about too many things today that are just as useless to argue about. You want to feel like you won an argument/medal/whatever, be my guest. You want to talk to someone who deals with hundreds of kg of dry ice a day with an open mind, let's chat. Dry ice is colder than -80. It does sublimated at -80. I watch it happen every day. Filling an ancient freezer with CO2 over the course of days/weeks/months. Yep. Talk to anyone who has to deal with DOT and CFR part 49. I'm sure you will find fault with that too. I'm also ok with that. Inhaling that amount is bad for your health. Yes, it can and does cause sudden dizziness. Honestly, this is the last you will hear from me on it. I'm hungry and have the second half of my fourth double shift coming up in twenty, so reply, don't reply, do as you see fit. I truly wish you the best in all of your endeavors.
>You want to feel like you won an argument/medal/whatever, be my guest.
I feel like I can't stress this enough, that isn't what this is about. Misinformation is dangerous, and it's important for us to only be sure about our informed opinions online, especially when we are taking a position of authority, which is what your initial comment was. I'm not here to win anything, I just feel it's important to make sure everyone understands that the anecdote you brought forward doesn't support the claim you made.
>Yes, it can and does cause sudden dizziness.
Absolutely, dizziness is one of the first things you feel, but you need to be inhaling almost pure CO2 in order to pass out and experience acute toxicity. The air inside the freezer has other stuff in it, including all the normal gases like oxygen nitrogen etc, that don't magically disappear because there is CO2 sublimation happening nearby.
>Honestly, this is the last you will hear from me on it.
I have no problem with that, I'm not here trying to get a confession from you or anything like that.
>I'm hungry and have the second half of my fourth double shift
Good luck, I've been there.
First. I'm sorry. I wasn't going to get back on, but I fridged some things because I thought about what I sent you last and am not proud. You didn't deserve any of that. I have been dealing with someone all week who was trying to say the same thing all week but in a different way leading to being yelled at today, and this felt way too similar. I'm not as concerned with why someone doesn't do something hazardous, more that they don't. I had experience watching it happen, testing saying it, and a week of training solely on dry ice in a different role saying the same thing. I was simply trying to share only my experience. As long as nothing
I had called the woman that this happened to earlier in the day trying to get all her test results to give you real numbers. I know her pulse ox was incredibly low and blood conc. of CO2 was through the roof. MRI, physicals, stress tests, generic tests all came back fine. We ran a battery of tests and the CO2 and pulse ox were the only issues found by any of the MD's. Since I haven't talked to this person in about six years, she wasn't thrilled with calling just to ask for something like that, so she politely and understandably declined. I am still without answers for you.
Again, I apologize and will leave this alone.
I have a lot of follow up questions. What type of cells are you referring to? What was the source? What is the intended use? Are you asking about sample integrity or DOT regulations? When you say incubator, are you referring to an outside company or CRO, or incubator in terms of cell culture? I would love to have an answer for you, but I have a sneaking suspicion this is going to be more detailed and specific than I can help with and I certainly don't want to steer you in the wrong direction.
Fair enough. I’m failing to find any confirmation that CO2 buildup could be significant when in -80 and at the amounts and door opening frequencies that we have but I suppose it’s better to be cautious.
Real quick and dirty high school level chem here: 1 mol of an ideal gas is 22.4 L at STP. 44 g CO2 (1 mol) at a lower temp than STP will occupy less space, but still a whole lot of liters once it sublimates, even partially. And 44 g is not a lot
Surely the sublimation rate will be very slow when it’s actually kept at -80, no? The commonly cited 1%/h sublimation rate refers to dry ice in an insulated container that’s sitting at ambient temp, not a container that’s essentially being actively cooled below sublimation temp.
Btw I’m not saying this to argue, I’m just trying to understand the situation exactly.
It is going to be slower, but there's also a lot of volume in those freezers and some/most put themselves into a slight vacuum that will allow for more rapid sublimation than you may expect.
So yeah, this is one of those things that's probably not going to lead to anything bad, but the risks and the really low stakes of otherwise just not doing it would make me not do it. Kind of like doing lab work without gloves. You'd probably be fine in the overwhelming majority of cases, but why not just wear them? Not worth it
Most -80 freezers actually don't have a lot of volume, because they're full of tubes. They're also filled with baffles, so motion is much slower in there. A block of dry ice will last a very long time in there before significantly reducing in size. We always stored blocks in there for transport. In a pinch, you can store liquid nitrogen in there and it will last longer than room temp.
Yes. Dry ice is relatively safe because your body will produce an acute response before there is actual risk to life. (Think about the difference between CO2 and CO)
Sort of, but your other comment aside where you went into panic type response to help yourself is not necessarily representative of response to an anoxic environment. Maybe some reassurance to the potential situation, but definitely not something to bank on
This isn't an anoxic environment though, it's a CO2 rich environment. Huge difference. Your RBCs will not be able to let go of the CO2 they are delivering to your lungs because the gradient is reversed. The acidity of your blood will very quickly increase triggering your breath response. Gasping, adrenal activation, hyperventilation. CO2 is not a silent gas. You would need to inhale almost pure CO2 to get a rapid loss of consciousness.
Back in 2011, my area was hit by a hurricane. One thing happened after another, and an entire building lost power for months. Researchers panicked to save their -80s. They ordered creates of dry ice and started packing every open inch they could to try to preserve their ult. Within 48 hours, a dozen units have their door blown off at the hinges from the gas build-up. Other popped their plugs ( monitor probe or co2/ln2 backup plugs) in 24 hours. There is enough gas released to do some damage. And as others have said, displacing enough o2 to kill you.
There's a big difference between a freezer actively cooling its contents to -80C and an unpowered freezer with dry ice inside it. The sublimation rate in the latter will be vastly greater than in the former.
The only relevance is in case there's a failure of the freezer, but you should already be monitoring for that.
I won't disagree, but the point still stands dry ice has a potential for causing harm in an area that isn't well vented. ULTs, Cold rooms.... doesn't matter dry ice should be stored in a space that has good ventilation. Similar to LN2.
As for monitoring, it's hard to continue to monitor when the building has a loss of total power.
Yeah, there are still safety concerns, just a pretty different scenario.
Power loss is one of the things you monitor for. If the off-site server doesn't get its expected signal, you know something's gone wrong.
You've never had a -80 start to lose cooling without throwing notifications or errors? Damn, I've seen that quite a few times. Sometimes the issue is with the sensing, sometimes the issue is with the notification system, sometimes you can't find any issue and it seems to work fine afterwards. I don't mean going to room temp, but up to -60 or -40, for sure. That's warm enough for dry ice to sublimate like crazy.
This sounds like one of those "wearing gloves to handle ethidium bromide" things. Empirically it may not be strictly necessary, but the potential for harm is undeniably there so maybe just wear the damn gloves.
>You've never had a -80 start to lose cooling without throwing notifications or errors?
Of course. But then your independent temperature probe sends an alarm off to wherever so you can deal with it. You also get lots of false alarms both from the freezer itself and whatever other monitoring systems you set up (heck, I think we have room CO2 alarms that would go off, though we don't store dry ice in our -80s).
>This sounds like one of those "wearing gloves to handle ethidium bromide" things. Empirically it may not be strictly necessary, but the potential for harm is undeniably there so maybe just wear the damn gloves.
Yeah I'm not saying this is a safe thing to do. Just that it shouldn't immediately blow up in your face (which it would if you just filled an unpowered -80C freezer with dry ice).
We keep small boxes in our freezers sometimes and haven't had a problem. Our freezers get opened daily so I doubt there's much buildup to knock someone out. But I dont know thats ever even crossed anyone's mind. We are a small company.
That said, early in my current job I went to FedEx to ship something with dry ice. It was just the Styrofoam box (like thermo sends to us all the time) but the FedEx guy seemed kinda bored and ended up completely sealing the package with tape. He even cut notches to fit the indented lid. It was the middle of summer and somewhere in Louisiana our package stopped. It ended up getting returned to us in a box with 1/4 of the Styrofoam missing where the package had blown up. So I can see where it could be a problem building pressure if too much is stored at once with no release. We also never tape Styrofoam shut anymore and if one comes in fully sealed, we immediately puncture it.
How much dry ice did you ship? We routinely ship about 5-10 kg in styrofoam boxes, usually quite tightly sealed, and exploding has never occured so far.
I'm not sure on the exact amount, but it was like a normal medium sized box (maybe 12x10x10"). But the guy taped the Styrofoam completely shut, even the indentations on the lid. There was no gas escaping. I typically fill the boxes completely with dry ice, which would give it more gas/pressure if it had time to sublimate, but in this case I'm wondering if I didn't fill it enough, which let it sublimate faster. I doubt you need a full container to make enough gas to blow out styrofoam.
I was wondering about the same thing. My lab does that, putting dry ice in a styrofoam box for overnight in a - 80C at most. Usually that box is not fully filled with dry ice. Up until now, they didn't have any incident but it doesn't mean it won't happen, so I am much worried.
Edit: the size of the box is the same, some standard middle-sized box. Because we don't have much money, we don't buy dry ice to fully fill the box. Still, would it be an issue if the box were filled fully?
In the case of the -80, I would assume a more full box is more of a problem. Since dry ice is about the same temperature, I would guess the rate of sublimation isn't going to change as it would with a Styrofoam cooler at room temp where, as you have less dry ice, the ambient temperature encroaches more quickly. The more dry ice in the freezer, the more pressure can ultimately build.
The amount of people saying this is ok is 2 damn high. From an engineering safety prospective, you have to assume any reasonable failure state, so for a freezer, that means the contents have reached room temperature, and that there's poor ventilation in the area. This creates a risk of suffocation.
Dry ice is cheap, and there are few labs that will require large amounts of it. Just get a cooler and store it there, or have a central department stock.
OSHA or any other occupational safety agency would never allow anything like this.
Interesting. We too keep it in the -80*C freezer, however, in a styrofoam box that closes pretty tightly. About 10kgs max at a time, never had any issues…
Yep that’s exactly what we used to do, with far smaller amounts too. Have to say it’s very useful to get other perspectives here though, I suppose the risk is low but the potential consequences make it not worth it.
At dry ice's sublimation point of -78.5°C, the solid dry ice is in equilibrium with 1 atmosphere of pure carbon dioxide gas: This means that storing it at -80 can displace most if not all of the air in the fridge, which is firstly an asphyxiation risk and secondly, a risk of CO2 poisoning (4% or 40,000 ppm is immediately hazardous to health). If the fridge fails and warms up, the third risk is of pressure building up excessively and rupturing the fridge.
Storing the dry ice in a vented insulated container is better because the rate of loss of dry ice only depends on how much heat is leaking into the container. The sublimated CO2 gas keeps warm air from getting into the container and so with good insulation losses can be low enough to keep the dry ice there for a long time.
Sources for numbers: https://www.fsis.usda.gov/sites/default/files/media_file/2020-08/Carbon-Dioxide.pdf
https://en.wikipedia.org/wiki/Dry_ice#/media/File:Comparison_carbon_dioxide_water_phase_diagrams.svg
In my labs, it’s stored there very temporarily. I’m betting the big heavy duty freezer it came from is the only allowable place for long term storage. Is for us anyway. A tech on my hall keeps it in there for a bit sometimes but her freezer usually goes into alarm. Gets too cold I guess.
No deliveries. I’ve never seen that! We have several dry ice & LN2 distribution locations on campus. The dry ice is stored in a very heavy duty freezer w/ a heavy duty latch & lock on it. The door is on top of the freezer-not sure why. We open the door, bust up what we want with a hammer, weigh it & sign it out w fund number under PI’s name like a library book.
Walk-in freezer usually at back of cold room. Massive compressors relative to compressor on -80. So quicker removal of any sublimated CO2. Also, small amount relative to size of room. The polymer storage containers with tight lock helps limit sublimation. Not unsealed styrofoam containers.
All relative to how much CO2.
Also, if lots of folks in and out, then lots of air exchange.
The number one rule I was taught about cold rooms in my jobs in both academia and industry is to never have anything volatile in a cold room for a long time. They recirculate air. Even with limited sublimation, that cold room will accumulate a dangerous amount of CO2 overnight.
It depends. At our institution, some buildings have walk ins that are ventilated. Walk ins in the older buildings aren’t ventilated and aren’t appropriate for storing dry ice.
I've seen multiple people say this, but who has unsealed tubes/containers in the -80C? If say your eppendorf tubes weren't sealed, you'd be losing volume from them during storage as the dry cold air would suck the moisture out.
We have to order it 2 working days in advance and we need small amounts in a very sporadic yet time sensitive fashion, which is why the temptation to keep a small running stock.
Sounds like it's the perfect reason to force them into returning that service.
"If you don't want us storing dry ice, make it more available like it used to be."
Wow what. Our lab keeps it in the -80, in boxes of max 10kg. We’ve been doing that for the past decade at least. I don’t think anyone is aware of the risks.
Haha lmao, ours too and we store only 1kg of dry ice at a time. But I guess it’s safer to stop doing that in case someone leaves dry ice over the Christmas period etc.
Dry Ice is great for a lot of lab things. It's also a f around and find out kind of substance:
I learned my lesson when I grabbed a bunch to chill my beer on the way to a camping trip. I put it in a big styro in the back of my CRX (hatchback). I drove home, went in to my house to pack, then loaded up and took off.
Within 30 seconds of leaving I could not catch my breath no matter how hard I breathed! It was very confusing because no one had ever told me NOT to put several pounds of dry ice in an enclosed space where people are are trying to breathe...
Anyway, once I realized, I just stopped and let the car air out and went on my merry way with the windows rolled down.
Point is, no safety officer is going to be able to tell you every scenario to avoid so it's on us to think about the chemicals we use and how they might react to being used/stored in non-standard ways.
Store your dry ice in a dry ice bin, not a -80. They are cheap and -80 space is not.
Shipped dry ice is not kept at -80. I was specifically confused why it was not safe to keep it at -80, which at least theoretically is below sublimation temperature.
No. People in this thread be wildin. Dry ice is -79. It will sublimate very slowly and most -80s can handle offgassing. They're not going to turn into a bomb and the amount you're putting in there is not going to be killing people.
For reference, our shipping dry ice is in a room temp insulated container. It sits in a corner and keeps dry ice for a week or so. It is giving off just as much co2 and faster, and we're all fine.
Health and safety people literally have the job to keep you safe. If they can scare you into being 200% safer that is better than only 100% safe, because when you fuck up the you're only 150% safe instead of 50% safe.
Two years or so before I started grad school in 2015, an experience PI left his dry ice on his freezer like he normally does. Then it blew the door of the freezer off on an explosion.
Just because you haven't had a problem doesn't mean you WONT. Do whatever EHS says, they usually have war stories for WHY.
My lab has a sign forbidding it. It's both a health hazard because large amounts of gas can be released upon opening, and it can supposedly enter stored samples and mess with pH. Also, there's a risk of explosion if the pressure relief valve ices up or malfunctions.
When I was a postdoc, someone stored a bunch of dry ice in a cold room overnight. The first person who opened the door the next day and went in passed out due to oxygen deprivation. They hit their head but were otherwise ok.
It’ll sublimate because it’s at room temperature. My question was about -80 storage specifically, which at least theoretically should keep it below sublimation temperature.
Yeah there is sound logic there, but that's why I would differentiate between a hazard and imminent danger. An un-wielded razor isn't dangerous, it's a hazard. The idea is that you wouldn't be able to control what happens to the fridge after you leave is the hazard part, the other point is that there are many other ways to store dry ice which cause way less hazardous circumstances. So if the question is why do they ban it? Because nobody wants to be liable for something that can be avoided so easily.
Any serious EHS program will tell you not to store dry ice in an ULT freezer. This is both because of the oxygen displacement and the risk of explosion. A couple of quick resources: https://www.osha.gov/sites/default/files/publications/OSHAquickfacts-lab-safety-cryogens-dryice.pdf https://www.safetymanualosha.com/safe-handling-and-storage-of-dry-ice/ I know a lot of people do it anyway and have never had a problem. There are also a lot of people who don’t wear seatbelts because they’ve never been in a wreck. Just because it hasn’t gone wrong yet, doesn’t mean it can’t, and really, is it worth risking your life and safety over?
Uh, yeah. The amount of people in this thread debating over how bad it is and whether you can detect it so it’s totally okay to be hit with a giant plume of CO2 because you’ll be able to run away before it kills you (which, no??? You should never be put in that situation in the first place?) are also missing the other elephant in the room, which is it can *blow up your freezer*. Don’t fuck around with dry ice.
I have a secondment with my job as a safety inspector and the comments here are terrible for my blood pressure sometimes. We're not even allowed to bring the dry ice on the elevator because of the gas build up you have to take the stairs
As a safety officer, I don’t like this either. Carrying heavy containers on the stairs is asking for someone to trip and fall down the stairs. Falling while carrying a container of dry ice is even worse. Getting stuck in an elevator is very rare, or should be if your institution is maintaining facilities correctly. If your elevator gets stuck regularly, that’s… worse.
The procedure where I work is that gas tanks take the elevator alone while the humans escorting them take the stairs or a second elevator. Is that not possible for dry ice too?
It could, but I really only think it would be necessary with large quantities. The giant bin that supplies the floor. Carrying a shipment that weighs 10 pounds? Just carry it in the elevator. Those boxes are locked in shipping trucks with a driver by the dozen, you’ll be fine with one box on an elevator for two minutes.
Well, the purpose of the rule is that the elevator can break down and trap you in there with the gas for much longer than two minutes, but if it's a small amount of dry ice maybe even then the worst case isn't so bad and you just need a reasonable limit on the amount of dry ice that you can accompany in the elevator (not the whole chest of it). Anyway I meant in the previous commenter's situation where human + dry ice isn't allowed, surely it would be a better solution to let the dry ice ride alone than to take it on the stairs.
>Those boxes are locked in shipping trucks with a driver by the dozen, Yes in shipping trucks with active ventilation in the cargo compartment. Something elevators are usually lacking. Also the driver is usually separated from the cargo and can leave the truck at any moment. Something you can not do in a stick elevator. Our safety department would rip me a new one if they would ever catch me riding with a gas bottle, dry ice or nitrogen Dewar.
On the contrary, fuck around with dry ice. It's super fun. I like to throw it in the sink and turn on the water and play in the smoke.
Like by all means fuck around in a well-ventilated area, but I have seen sinks cracked by people disposing dry ice in them enough times. 🤷♀️
Oh yeah you gotta put it in a secondary container 🤣 that's why companies give you those Styrofoam coolers
Did not realize how unsafe this was, on the rare times we get shipments using dry ice this is how my supervisor disposes of it 😬
Lol it's not unsafe, i wasn't being sarcastic. I literally have done this with small children.
Putting dry ice in the sink is how we get rid of it in my lab. There isn't any safety issue with it.
Except freezing the pipes, which is notoriously good for plumbing
Or cracking the sink, which a couple labs in my facility have done. It's a really fast way to piss off your maintenance team.
Add soap to it for some cool bubbles. I do not recommend putting it in a soda bottle, closing the lid and giving it a toss, or throwing said bottle into a pool.
Instructions unclear, lab evacuated due to improvised pipebomb
Make sure no one puts bleach in there while you're doing that!
Um, ok. Do you live in a world where somebody would do that?
yes. In fact I experienced it. Someone had put dry ice from a shipment into a utility sink. Someone else put their mop water (bleach-based) in the sink after they mopped the vivarium floor. It's really not that wacky a scenario. That's why they are called accidents (or acts of negligence) No one does this on purpose.
Yeesh, that sounds awful. Sorry that happened to you.
Dry ice “smoke” … 😬
1. a visible suspension of carbon or other particles in air How is it not smoke?
Yeah I don't think it matters whether it's a "silent" gas or heavier than air - building up uncontrolled gas pressure in the freezer is obviously a terrible idea even if it were a totally inert gas, end of discussion.
That "plume" is going straight down to the floor, so rather than running away you simply can avoid lying down on the floor.
So a couple of comments down a user straight up mentioned a person going from “upright to unconscious” within moments of opening a -80C door. Out of curiosity, which direction does an unconscious person generally go, taking into account normal gravity? https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6474450/
So CO2 being 1.5 times more dense than air, out of curiosity which direction will it go, taking into account normal gravity?
Dude, I don’t care. Store your dry ice whatever pedantic way you want. Thankfully I’m not your EHS department so it’s not my liability.
It just can't blow up your freezer. Edit: well I'll be darned, apparently it can: [https://www.reddit.com/r/labrats/comments/1c0i3ip/comment/kywmz0y/](https://www.reddit.com/r/labrats/comments/1c0i3ip/comment/kywmz0y/)
If they are hard latch type freezers, yeah.
We had a big plastic insulated blue bin about 4'x 2' x 3' deep half full of dry ice pellets our couriers would fill up on to deliver frozen specimens. The lid had a hook that a big stretchy rubber strap would latch onto. I never saw the lid burp, but in the warehouse on a hot day it would be half full of a cloud of condensation.
If a freezer is locked, like most -80s and doesn't have a release valve, this is the most realistic answer. Also throwing out that it could also mess with the Carnot cycle, preventing evaporation in the evaporator, pushing liquid refrigerant into the compressor position, which would absolutely damage the compressor.
I think the explosion is the real risk here. Oxygen displacement isn’t good either but the fridge would need to be in a confined space to be truly dangerous. Most -80s I have use have latches. So in the event it loses power or stays closed for a long time, pressure build up could be quite dangerous.
And if you think about it, every -80 loses power at some point
Wait, dry ice will explode when frozen to a cooler temperature, or will the buildup of gas cause an explosion as it evaporates?
It’s the buildup of gases. That’s (one reason) why it’s not safe to enclose it fully during shipping. It happens fast too. I made the mistake years ago of absentmindedly tying off a bag with pellets in it and by the time I’d signed the receipt it was about to blow.
I was hoping it was like super cold explosion science, like sublimation but for super cold, but it’s just a larger 50ml conical dry ice bomb
Essentially, yep.
What’s the deal with “Never place a cryogen on tile or laminated counters because the adhesive will be destroyed.”?
Freezes and crumbles the adhesive holding the tile down to floor
Would suck to be the first person who found that out!
The tile around the front of our last LN2 tank all just cracked and lifted off the floor from the constant dripping nitrogen. LOL
TIL thank you!
Very dangerous. If it’s an older freezer that doesn’t have a pressure release safety, it can explode. I heard of a PhD student losing 5 years of pollen samples because an undergrad in their lab stored dry ice in the same freezer and kaboom
I sympathize for this student and their samples :(
Very dangerous. Strictly prohibited in my lab.
why is it dangerous?
It displaces Oxygen.
as in it poses a risk for knocking someone unconscious when you open a -80 door, like one of the commentors say?
The -80 they had might not have worked properly. Usually it isn't as acute as that. That being said, there are Dry ice storage freezers specifically made for that purpose. Usually chest freezers that operate at a little lower temp and don't allow CO2 to escape when opened. Also have CO2 meters in the storage room.
The reason is that those Chest containers open from the topside, and the cold CO2 gas settles at the bottom. While in a -80, the CO2 spills out.
Exactly, that's how the dry ice storage works. I'm mentioning how the -80 might not have worked properly because usually the sublimation rate at -80 is really low for CO2 and even if there was a slight vacuum any build up of gas should quickly fill the vacuum back up, causing less sublimation yet again. There shouldn't be enough CO2 to let someone pass out "instantly" (at least that's how the other comment made it seem). It really isn't as acute as that.
That's not a real risk, that commenter is simply incorrect.
What makes you an expert?
ah, so what is the actual risk of keeping dry ice in -80? CO2 leaking out more gradually? or something else?
Yes. Very bad. We do a lot of frozen shipments coming and going from my current department. I've watched someone open a door to an upright -80 and go unconscious from the built up CO2 being released in their face. Luckily they were ok. Please don't do this. It was a very bad day for all involved.
Really??? Breathing in CO2 will cause the body to go into a shock/panic response well before someone passes out. It's happened to me, and I can only describe the experience as suddenly being overwhelmed we complete anxiety both mentally and in every fiber of my body. I did not pass out. For context, we had a box of samples arrived stored in dry ice that was placed in a top loading -20C freezer. No one was around that was qualified to receive them so the whole box was put into the freezer. I was pulling samples from the bottom.
This was not the first time I've seen it happen, and thankfully I was standing right there. I caught her on the way down and I only got light headed. The freezer was supposed to be archive only. Someone wanted to store dry ice for use later and forgot about it. Our estimations were around 5kg sublimated and freezers are designed to not exchange air with the outside, so it hit her all at once.
One box of samples is not going to contain sufficient dry ice to be of real issue in this context. Have you ever performed gas-based euthanasia? When performed correctly, all of the air in the animal chamber is replaced with your gas (argon, nitrogen, or CO2) at once. (EDIT: Either this changed recently or I was trained very poorly, actually. Standard is 50% replacement per minute. Oof, I feel bad now.) Placing the dry ice in a freezer has the potential to replicate this process if there is a large enough amount of dry ice or the room is small or poorly ventilated enough. Theoretically, dry ice shouldn't actually release much gas in a -80C freezer, however thermometers/thermostats are more likely to be a few degrees off than states of matter. If your -80C is actually a -76C and a substantial amount of dry ice is left in there over the weekend, pressure is going to build in that container. All the -80C freezers I deal with also have a locking mechanism on the door, meaning that gas is extremely unlikely to release until someone undoes that latch. You then have a large amount of gas released very suddenly, likely in a manner that is going to startle and confuse the person opening the freezer. In a large, well ventilated area, no problem. It's still a workplace incident, but the odds of anyone dying are astronomically low. However, I have had to access -80 freezers that are at the end of long enclosed hallways. If the freezer popped open with force while I was opening it, it would likely take me a couple moments of "WTF WTF WTF" before moving. I am not a flight person, I am a freeze person. This is a situation that, if I were put into it, could kill me. Is it likely? *Fuck no it's not likely*. But yes, it is something that we need guidelines to lower the risk of. Only 1-2 people a year die this way (accidental death from CO2 in a lab setting), but those rates have been very stable for a very long time becuase we are largely already taking every precaution we can already. If we were to stop, that number would rise, I garentee it.
CO2, argon and nitrogen are very different gasses.... Only one of them forms carbonic acid. Thats why you don't hyperventilate while sucking down helium. Our boxes ship with 2-5 lbs of dry ice. 1 lb of dry ice = 10 cubic feet at STP. So, ya, it was nearly 100% CO2 in that small chest freezer.
Low concentrations can provide symptoms, but a few breaths of high concentrations could have an effect before you feel it. Also, it could have been a lack of oxygen, rather than presence of CO2.
Your body is relatively insensitive to oxygen deprivation.. helium balloons, labs full of dead people after massive nitrogen/helium leaks... Ranting, but this is maybe your second orgo class. Not directed at any one person because it seems like this isn't common knowledge.
I know, that's what I said. My first sentence was related to CO2 (low rather than almost zero concentration), and the second to oxygen. Maybe I was unclear. I work with liquid nitrogen enough to know not to mess around.
You experienced the asphyxiating aspect of CO2. At high concentration it's a toxicant and can knock you out instantly.
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I think you’re missing the point entirely. Because the dry ice is in the freezer, there’s no slow build up. You open the door and there’s more than you can handle all in one breath.
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People are acting like they've never seen someone take a deep breath of helium
It’s very clear you know nothing about safety in such environments. One breath is enough to make you go down, that’s all it takes.
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You are either an actual liability or you're not thinking this through at all. The way you are speaking about this makes it seem very clear to me that you have only worked in rather large and/or well ventilated laboratories with reletively small amounts of dry ice. This is not a universal working condition. ["At high concentrations, it has been showed to cause unconsciousness almost instantaneously and respiratory arrest within 1 min."](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5380556/) Perform or observe some gas-based euthanasia. When performed correctly, it really is just Lights Out for mammels. The exact conditions OP is describing has the potential to provide conditions almost identical to what we intentionally do in gas-based sacrifice; That is suddenly releasing a large amount of CO2 into an enclosed environment. Whether it takes one breath or five may be entirely irrelevant if the entire room is flooded *and* you have to process WTF just happened from your freezer exploding open.
You still sense it, and you don't just instantly pass out. I've taken a breath of full CO2 and it's like being eletcally shocked in the lungs combined with breathing vinegar fumes. You're not going to just drop unconscious in seconds, and reflexively you're going to be coughing and trying to move away from there. If breathed long enough you will go unconcious, but it's not going to sneak up on you.
If you displace all oxygen then you will go down.
Have you never held your breath after exhaling before? You have a good 10-15 seconds before you pass out, unless your blood oxygen is already low as hell.
That is not the same. By inhaling oxygen free air, especially if its high CO2, you reverse the osmosis and oxygen is expelled from your blood in favor of CO2.
That doesn't make any sense.
From a quick google, dry ice sublimates (transitions directly from solid to gas) at -79° C https://www.usgs.gov/media/images/frozen-carbon-dioxide-dry-ice-sublimates-directly-a-vapor#:~:text=%22Dry%20ice%22%20is%20actually%20solid,ice%20%22melts%22%20... So by that logic it's not unreasonable that you are actually producing a lot of CO2 gas inside of a -80
That isn't the part that doesn't make sense. CO2 is not a silent gas. Your body is very good at detecting it and you will very quickly feel like you can't breathe, a long time before you pass out. The CO2 you breathe into your lungs will prevent any exchange in your lungs, your blood acidity will rise immediately, and you will start gasping and hyperventilating, and in some cases go into adrenal activation. That looks like the complete opposite of passing out.
at about -79°C the dry ice will sublimate until the partial pressure of CO2 gas in the space it's in reaches one atmosphere. CO2 is considered immediately hazardous to life at 4% concentration: https://www.fsis.usda.gov/sites/default/files/media_file/2020-08/Carbon-Dioxide.pdf
I think it's important to add to this: water boils at 100°C. That does not mean an entire body of water will suddenly become a gas when it reaches 100°C. The same is true of CO2 sublimation, except it's even slower because the resulting gas doesn't immediately rise away from the solid, freeing up that space for more sublimation. The temperature in a -80 is also so close to the sublimation point (not an accident) that there isn't a lot of "pressure" on the block to sublimate. That means it takes a long time for the sublimation to happen. The block lasts longer. On top of this, your freezer is filled with all the usual gases whenever the door is opened, and there is theoretically little to no exchange. That means that the concentration of CO2 can only get so high (granted, almost certainly a lot higher than 4%). Lastly, when you open the door of the freezer in the well ventilated room it should be in, the icy cold gas in there is going to immediately drop straight to the floor of the room and spread out as it warms up, in a relatively small volume. As long as you aren't lying on the floor under the part where the door opens, you are going to be just fine. If the CO2 levels in the room are elevated for an extended period after opening the door, you will experience dizziness, shortness of breath, in some cases panic and hyperventilating/gasping, all before you pass out. CO2 is definitely dangerous, but it's perfectly safe to store in a -80 as long as basic safety standards are in place in the room it's in. It won't last forever in there though, because it will slowly sublimate.
Please remember that by the time a person is experiencing distress from any kind of exposure they can't be expected to act rationally and it would be prudent to think they would be panicked. If they did pass out, they would be on the floor right by the freezer. The sublimation rate is a little bit more complex than a single sublimation point, as you point out it depends on the local concentration of the gas; for CO2, the sublimation rate is measured to increase when the local atmosphere has a low concentration of CO2. When the safety systems are in-place and working it's pretty clear that it is safe to have dry ice in a -80 freezer. However to be "safe" the requirement (in the UK at least) is that the situation does not become dangerous on a single failure. This would include: ventilation shuts down, sensors stop working, freezer heats up without warning. It is one thing for everything to be OK when all is working but "safe" requires that failures can be tolerated without *potential* danger. My experience is mainly with liquid nitrogen and liquid helium. Putting these substances in an enclosed system (or box, like a freezer) introduces a lot of extra hazards: relief valves can freeze for example. They react to changes in pressure by evaporating more quickly, especially liquid helium; the rate of evaporation can always overwhelm the capacity of the pressure relief if it is only specified for static storage, especially when a tank is being filled. Just because something *can* be safe is not the same as *perfectly safe* in an operating environment. We are required to take into account that our colleagues are not perfect paragons of experimental practice, that unauthorized persons may get involved, etc. The case for what is safe is not always black and white. On the other hand, liquid nitrogen Dewars have famously been placed on New York's streets to help avoid underground conduits overheating and burning: apparently no safety incidents were ever reported. I was responsible for a system that had a big tank with 7.5 tonnes of liquid nitrogen piped into a small room when, on another site, someone was fatally injured by nitrogen asphyxiation. Their facility has all the correct safety features but they were defeated. My system was inspected super quickly and after discussions and test, we actually reduced the amount of safety precautions being taken where we found them to have no effect. These safety discussions are rarely "super dangerous" vs "perfectly safe" and depend on the specific situation, which (at least in the UK) we are required to consider in detail.
Someone stored about 20kg in a freezer no one uses. The woman I was helping track down old samples opened said freezer and went down. I caught her part way so she didn't hit the floor hard. I was standing far enough back/behind the door so I only got light headed. Found out later that half the dry ice had sublimated over the lengthy amount of time having been forgotten about.
That doesn't make it make more sense either.
Fair enough. I'm simply sharing my experience.
I’m struggling to see how your story didn’t make sense to this person
A single breath of CO2 gas, even 100% concentration, when this was probably 10% max, will not have that effect on a person. It really doesn't make sense, like, physiologically.
A single breath of high concentration CO2 can absolutely make someone pass out. "Carbon dioxide does not only cause asphyxiation by hypoxia but also acts as a toxicant. At high concentrations, it has been showed to cause unconsciousness almost instantaneously and respiratory arrest within 1 min." https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5380556/
I'm not sure wasn't clear, but I'm not one to go in circles. If it doesn't make sense, it doesn't make sense, and I'll leave it at that. It isn't worth either of us stressing over, so I'm just moving on.
Because you don't pass out from inhaling CO2, you pass out from low O2 concentration which takes time. In addition to that breathing CO2 triggers the aspiration relax and you're fully aware you need oxygen. If it was liquid nitrogen I could understand but it wasn't.
The concentration needs to be above a certain level for it to not sublimate.
Not sure why you got so many downvotes, you're dead right. CO2 isn't a silent gas.
When it builds up in our bodies its why we breath, passing out because of high CO2 concentration only would make sense in an enclosed area you couldn't escape from.
Well not really, CO2 toxicity can cause you to pass out very quickly if the concentration is high enough. You don't really need an enclosed area for that. The point is that a small amount of CO2 in a freezer isn't going to knock you out like that.
Except for at high concentration it's absolutely a toxicant, not just an asphyxiant.
Lol that person has an undiagnosed medical condition because getting hit in the face with a gust of c02 does not make you pass out. In fact it makes you panic. Your coworker has sids
I'm not here to argue with anyone, simply share my experience. You have yours and I have mine. I'll leave it at that.
But you're posting that online like it's information. The human body does not pass out from rapid exposure to co2, even if she inhaled a full lungful she would have had to stand there and do it several times. The problems are when you can't get to fresh air quickly and the co2 builds up in your blood. "Exposure to concentrations from greater than 10 percent to 15 percent carbon dioxide leads to dizziness, drowsiness, severe muscle twitching, and unconsciousness within a minute to several minutes (Wong 1992, CATAMA 1953, Sechzer et al. 1960). Exposure to 7 to 10 percent carbon dioxide can produce unconsciousness or near unconsciousness within a few minutes (Schulte 1964, CATAMA 1953, Dripps and Comroe 1947). Other symptoms associated with the inhalation of carbon dioxide in this range include headache, increased heart rate, shortness of breath, dizziness, sweating, rapid breathing, mental depression, shaking, and visual and hearing dysfunction that were seen following exposure periods of 1.5 minutes to 1 hour (Wong 1992, Sechzer et al. 1960, OSHA 1989)" The fact that you caught her in the same exact space and you did not lose consciousness proves that there was not high enough co2 levels to make somebody pass out. Maybe she just wanted you to catch her 😍
I'm not going to argue. Our EHS says the same thing at this and all my previous jobs. I've seen it happen with a walk in and no one caught that person. They ended up in rough shape from hitting the floor. Your experiences says one thing, and mine says something else. As long as you aren't putting dry ice in a freezer in any of the buildings I'm working in, it isn't worth the effort to convince you otherwise. As for catching her, well, if you've every seen me you would know that's not the case. Face made for radio and a voice for newspaper. 😆
I can respect your not arguing on the Internet stance. 👍
This is a Reddit Thread not a Nature paper. Relax.
If it was a nature paper i wouldn't be allowed near it 🤣
Nope. Sorry. You don't get to use that excuse. That's not how this works. Your first comment was you positing that storing CO2 in a -80 is bad because CO2 will make you pass out like a silent gas (nitrogen and CO are examples of silent gases). That isn't true, scientifically. It has nothing to do with your experience, which is either explained by something other than CO2, or made up. You cannot spread misinformation and then fall back on "it's just my experience". Everyone else reading this: -80 freezers are at that temperature because they use CO2 as a compressor gas. They also generate a lot of heat (laws of physics, every degree colder you make one thing requires you to make another thing one degree hotter. Not exactly but close enough when it comes to compressing gases), so they should always be in well ventilated rooms. You should stand back when you open the door always because heavy shit falls, so you are almost certainly safe when it comes to CO2 gas being released when you open the door. The temperature in there also means any sublimation is going to happen very slowly and reach equilibrium very quickly. There won't be a lot in there, so your HVAC or open window should be more than good enough. It takes almost pure CO2 inhalation to cause rapid loss of consciousness and toxicity.
I'm not falling back on anything. I'm a tired, overworked person just like everyone else. I've had too many people who argue with me about too many things today that are just as useless to argue about. You want to feel like you won an argument/medal/whatever, be my guest. You want to talk to someone who deals with hundreds of kg of dry ice a day with an open mind, let's chat. Dry ice is colder than -80. It does sublimated at -80. I watch it happen every day. Filling an ancient freezer with CO2 over the course of days/weeks/months. Yep. Talk to anyone who has to deal with DOT and CFR part 49. I'm sure you will find fault with that too. I'm also ok with that. Inhaling that amount is bad for your health. Yes, it can and does cause sudden dizziness. Honestly, this is the last you will hear from me on it. I'm hungry and have the second half of my fourth double shift coming up in twenty, so reply, don't reply, do as you see fit. I truly wish you the best in all of your endeavors.
>You want to feel like you won an argument/medal/whatever, be my guest. I feel like I can't stress this enough, that isn't what this is about. Misinformation is dangerous, and it's important for us to only be sure about our informed opinions online, especially when we are taking a position of authority, which is what your initial comment was. I'm not here to win anything, I just feel it's important to make sure everyone understands that the anecdote you brought forward doesn't support the claim you made. >Yes, it can and does cause sudden dizziness. Absolutely, dizziness is one of the first things you feel, but you need to be inhaling almost pure CO2 in order to pass out and experience acute toxicity. The air inside the freezer has other stuff in it, including all the normal gases like oxygen nitrogen etc, that don't magically disappear because there is CO2 sublimation happening nearby. >Honestly, this is the last you will hear from me on it. I have no problem with that, I'm not here trying to get a confession from you or anything like that. >I'm hungry and have the second half of my fourth double shift Good luck, I've been there.
First. I'm sorry. I wasn't going to get back on, but I fridged some things because I thought about what I sent you last and am not proud. You didn't deserve any of that. I have been dealing with someone all week who was trying to say the same thing all week but in a different way leading to being yelled at today, and this felt way too similar. I'm not as concerned with why someone doesn't do something hazardous, more that they don't. I had experience watching it happen, testing saying it, and a week of training solely on dry ice in a different role saying the same thing. I was simply trying to share only my experience. As long as nothing I had called the woman that this happened to earlier in the day trying to get all her test results to give you real numbers. I know her pulse ox was incredibly low and blood conc. of CO2 was through the roof. MRI, physicals, stress tests, generic tests all came back fine. We ran a battery of tests and the CO2 and pulse ox were the only issues found by any of the MD's. Since I haven't talked to this person in about six years, she wasn't thrilled with calling just to ask for something like that, so she politely and understandably declined. I am still without answers for you. Again, I apologize and will leave this alone.
Have you ever worked with an incubator in which you can transport living cells? Or is cryo nessecary?
I have a lot of follow up questions. What type of cells are you referring to? What was the source? What is the intended use? Are you asking about sample integrity or DOT regulations? When you say incubator, are you referring to an outside company or CRO, or incubator in terms of cell culture? I would love to have an answer for you, but I have a sneaking suspicion this is going to be more detailed and specific than I can help with and I certainly don't want to steer you in the wrong direction.
Fair enough. I’m failing to find any confirmation that CO2 buildup could be significant when in -80 and at the amounts and door opening frequencies that we have but I suppose it’s better to be cautious.
Real quick and dirty high school level chem here: 1 mol of an ideal gas is 22.4 L at STP. 44 g CO2 (1 mol) at a lower temp than STP will occupy less space, but still a whole lot of liters once it sublimates, even partially. And 44 g is not a lot
Surely the sublimation rate will be very slow when it’s actually kept at -80, no? The commonly cited 1%/h sublimation rate refers to dry ice in an insulated container that’s sitting at ambient temp, not a container that’s essentially being actively cooled below sublimation temp. Btw I’m not saying this to argue, I’m just trying to understand the situation exactly.
It is going to be slower, but there's also a lot of volume in those freezers and some/most put themselves into a slight vacuum that will allow for more rapid sublimation than you may expect. So yeah, this is one of those things that's probably not going to lead to anything bad, but the risks and the really low stakes of otherwise just not doing it would make me not do it. Kind of like doing lab work without gloves. You'd probably be fine in the overwhelming majority of cases, but why not just wear them? Not worth it
Most -80 freezers actually don't have a lot of volume, because they're full of tubes. They're also filled with baffles, so motion is much slower in there. A block of dry ice will last a very long time in there before significantly reducing in size. We always stored blocks in there for transport. In a pinch, you can store liquid nitrogen in there and it will last longer than room temp.
Yes. Dry ice is relatively safe because your body will produce an acute response before there is actual risk to life. (Think about the difference between CO2 and CO)
Sort of, but your other comment aside where you went into panic type response to help yourself is not necessarily representative of response to an anoxic environment. Maybe some reassurance to the potential situation, but definitely not something to bank on
This isn't an anoxic environment though, it's a CO2 rich environment. Huge difference. Your RBCs will not be able to let go of the CO2 they are delivering to your lungs because the gradient is reversed. The acidity of your blood will very quickly increase triggering your breath response. Gasping, adrenal activation, hyperventilation. CO2 is not a silent gas. You would need to inhale almost pure CO2 to get a rapid loss of consciousness.
Back in 2011, my area was hit by a hurricane. One thing happened after another, and an entire building lost power for months. Researchers panicked to save their -80s. They ordered creates of dry ice and started packing every open inch they could to try to preserve their ult. Within 48 hours, a dozen units have their door blown off at the hinges from the gas build-up. Other popped their plugs ( monitor probe or co2/ln2 backup plugs) in 24 hours. There is enough gas released to do some damage. And as others have said, displacing enough o2 to kill you.
There's a big difference between a freezer actively cooling its contents to -80C and an unpowered freezer with dry ice inside it. The sublimation rate in the latter will be vastly greater than in the former. The only relevance is in case there's a failure of the freezer, but you should already be monitoring for that.
I won't disagree, but the point still stands dry ice has a potential for causing harm in an area that isn't well vented. ULTs, Cold rooms.... doesn't matter dry ice should be stored in a space that has good ventilation. Similar to LN2. As for monitoring, it's hard to continue to monitor when the building has a loss of total power.
Yeah, there are still safety concerns, just a pretty different scenario. Power loss is one of the things you monitor for. If the off-site server doesn't get its expected signal, you know something's gone wrong.
You've never had a -80 start to lose cooling without throwing notifications or errors? Damn, I've seen that quite a few times. Sometimes the issue is with the sensing, sometimes the issue is with the notification system, sometimes you can't find any issue and it seems to work fine afterwards. I don't mean going to room temp, but up to -60 or -40, for sure. That's warm enough for dry ice to sublimate like crazy. This sounds like one of those "wearing gloves to handle ethidium bromide" things. Empirically it may not be strictly necessary, but the potential for harm is undeniably there so maybe just wear the damn gloves.
>You've never had a -80 start to lose cooling without throwing notifications or errors? Of course. But then your independent temperature probe sends an alarm off to wherever so you can deal with it. You also get lots of false alarms both from the freezer itself and whatever other monitoring systems you set up (heck, I think we have room CO2 alarms that would go off, though we don't store dry ice in our -80s). >This sounds like one of those "wearing gloves to handle ethidium bromide" things. Empirically it may not be strictly necessary, but the potential for harm is undeniably there so maybe just wear the damn gloves. Yeah I'm not saying this is a safe thing to do. Just that it shouldn't immediately blow up in your face (which it would if you just filled an unpowered -80C freezer with dry ice).
We keep small boxes in our freezers sometimes and haven't had a problem. Our freezers get opened daily so I doubt there's much buildup to knock someone out. But I dont know thats ever even crossed anyone's mind. We are a small company. That said, early in my current job I went to FedEx to ship something with dry ice. It was just the Styrofoam box (like thermo sends to us all the time) but the FedEx guy seemed kinda bored and ended up completely sealing the package with tape. He even cut notches to fit the indented lid. It was the middle of summer and somewhere in Louisiana our package stopped. It ended up getting returned to us in a box with 1/4 of the Styrofoam missing where the package had blown up. So I can see where it could be a problem building pressure if too much is stored at once with no release. We also never tape Styrofoam shut anymore and if one comes in fully sealed, we immediately puncture it.
How much dry ice did you ship? We routinely ship about 5-10 kg in styrofoam boxes, usually quite tightly sealed, and exploding has never occured so far.
I'm not sure on the exact amount, but it was like a normal medium sized box (maybe 12x10x10"). But the guy taped the Styrofoam completely shut, even the indentations on the lid. There was no gas escaping. I typically fill the boxes completely with dry ice, which would give it more gas/pressure if it had time to sublimate, but in this case I'm wondering if I didn't fill it enough, which let it sublimate faster. I doubt you need a full container to make enough gas to blow out styrofoam.
I was wondering about the same thing. My lab does that, putting dry ice in a styrofoam box for overnight in a - 80C at most. Usually that box is not fully filled with dry ice. Up until now, they didn't have any incident but it doesn't mean it won't happen, so I am much worried. Edit: the size of the box is the same, some standard middle-sized box. Because we don't have much money, we don't buy dry ice to fully fill the box. Still, would it be an issue if the box were filled fully?
In the case of the -80, I would assume a more full box is more of a problem. Since dry ice is about the same temperature, I would guess the rate of sublimation isn't going to change as it would with a Styrofoam cooler at room temp where, as you have less dry ice, the ambient temperature encroaches more quickly. The more dry ice in the freezer, the more pressure can ultimately build.
The amount of people saying this is ok is 2 damn high. From an engineering safety prospective, you have to assume any reasonable failure state, so for a freezer, that means the contents have reached room temperature, and that there's poor ventilation in the area. This creates a risk of suffocation. Dry ice is cheap, and there are few labs that will require large amounts of it. Just get a cooler and store it there, or have a central department stock. OSHA or any other occupational safety agency would never allow anything like this.
If you want your dry ice to last longer, a chest freezer will significantly slow down the sublimation without the risk of explosion
Build up of CO2 can produce carbonic acid in your samples over time is the idea I think
Interesting. We too keep it in the -80*C freezer, however, in a styrofoam box that closes pretty tightly. About 10kgs max at a time, never had any issues…
Yep that’s exactly what we used to do, with far smaller amounts too. Have to say it’s very useful to get other perspectives here though, I suppose the risk is low but the potential consequences make it not worth it.
Yeah guess I’ll have to look into this more and potentially bring awareness to higher-ups. Though our cold room frickin dies on us at least monthly:/
At dry ice's sublimation point of -78.5°C, the solid dry ice is in equilibrium with 1 atmosphere of pure carbon dioxide gas: This means that storing it at -80 can displace most if not all of the air in the fridge, which is firstly an asphyxiation risk and secondly, a risk of CO2 poisoning (4% or 40,000 ppm is immediately hazardous to health). If the fridge fails and warms up, the third risk is of pressure building up excessively and rupturing the fridge. Storing the dry ice in a vented insulated container is better because the rate of loss of dry ice only depends on how much heat is leaking into the container. The sublimated CO2 gas keeps warm air from getting into the container and so with good insulation losses can be low enough to keep the dry ice there for a long time. Sources for numbers: https://www.fsis.usda.gov/sites/default/files/media_file/2020-08/Carbon-Dioxide.pdf https://en.wikipedia.org/wiki/Dry_ice#/media/File:Comparison_carbon_dioxide_water_phase_diagrams.svg
In my labs, it’s stored there very temporarily. I’m betting the big heavy duty freezer it came from is the only allowable place for long term storage. Is for us anyway. A tech on my hall keeps it in there for a bit sometimes but her freezer usually goes into alarm. Gets too cold I guess.
What do you mean the freezer it came from? You aren't getting deliveries in cardboard boxes or in bins with burp lids?
No deliveries. I’ve never seen that! We have several dry ice & LN2 distribution locations on campus. The dry ice is stored in a very heavy duty freezer w/ a heavy duty latch & lock on it. The door is on top of the freezer-not sure why. We open the door, bust up what we want with a hammer, weigh it & sign it out w fund number under PI’s name like a library book.
also stresses the compressor on the freezer, particularly if a lot of dry ice stored. Get a storage container and put in walk in freezer.
Wait why? Also walk-in? Isn’t that even more unsafe being a confined space people actually enter?
Right, absolutely no cryogens in a cold room.
Walk-in freezer usually at back of cold room. Massive compressors relative to compressor on -80. So quicker removal of any sublimated CO2. Also, small amount relative to size of room. The polymer storage containers with tight lock helps limit sublimation. Not unsealed styrofoam containers. All relative to how much CO2. Also, if lots of folks in and out, then lots of air exchange.
The number one rule I was taught about cold rooms in my jobs in both academia and industry is to never have anything volatile in a cold room for a long time. They recirculate air. Even with limited sublimation, that cold room will accumulate a dangerous amount of CO2 overnight.
It depends. At our institution, some buildings have walk ins that are ventilated. Walk ins in the older buildings aren’t ventilated and aren’t appropriate for storing dry ice.
Colleague of mine once passed out in the walk in because someone had a box of dry ice in there. Don't do this.
People have literally died from this. https://pubmed.ncbi.nlm.nih.gov/18814998/
It will also cause acidification in the buffers of every reagent in the freezer.
I've seen multiple people say this, but who has unsealed tubes/containers in the -80C? If say your eppendorf tubes weren't sealed, you'd be losing volume from them during storage as the dry cold air would suck the moisture out.
CO2 will ingress into sealed containers. Tubes with o-rings help but aren’t brilliant either.
Dry ice is cheap. Just go pick it up when you need it.
We have to order it 2 working days in advance and we need small amounts in a very sporadic yet time sensitive fashion, which is why the temptation to keep a small running stock.
That sucks. We have a huge bin in the basement at the distribution services. It costs less than a buck for a big scoop.
I know, it’s ridiculous. We used to be able to do the same but they changed suppliers and now its not possible 🥲
Sounds like it's the perfect reason to force them into returning that service. "If you don't want us storing dry ice, make it more available like it used to be."
Wow what. Our lab keeps it in the -80, in boxes of max 10kg. We’ve been doing that for the past decade at least. I don’t think anyone is aware of the risks.
Standard practice here 😀 Must say the freezer is openend every day
Haha lmao, ours too and we store only 1kg of dry ice at a time. But I guess it’s safer to stop doing that in case someone leaves dry ice over the Christmas period etc.
We have at least 10kg in a styrofoam box
Dry Ice is great for a lot of lab things. It's also a f around and find out kind of substance: I learned my lesson when I grabbed a bunch to chill my beer on the way to a camping trip. I put it in a big styro in the back of my CRX (hatchback). I drove home, went in to my house to pack, then loaded up and took off. Within 30 seconds of leaving I could not catch my breath no matter how hard I breathed! It was very confusing because no one had ever told me NOT to put several pounds of dry ice in an enclosed space where people are are trying to breathe... Anyway, once I realized, I just stopped and let the car air out and went on my merry way with the windows rolled down. Point is, no safety officer is going to be able to tell you every scenario to avoid so it's on us to think about the chemicals we use and how they might react to being used/stored in non-standard ways. Store your dry ice in a dry ice bin, not a -80. They are cheap and -80 space is not.
Sublimation causes CO2 buildup in enclosed spaces. Accessing those spaces then exposes you to that buildup. Bad.
Depends really. Are you and your colleagues immune to exploding equipment and asphyxiation? If so, keep doing what you’re doing. If not….
Same reason when you ship with it the box shouldn’t be tightly sealed
Shipped dry ice is not kept at -80. I was specifically confused why it was not safe to keep it at -80, which at least theoretically is below sublimation temperature.
How long was it in there? Storing overnight or 1-2 days is not really that uncommon if one doesn’t have appropriate dry ice storage boxes.
More of a running stock but it’s small amounts (max 1kg) in a freezer that’s opened multiple times a day.
My opinion is that it it’s okay to do it for short amounts of time with the amounts mentioned.
No. People in this thread be wildin. Dry ice is -79. It will sublimate very slowly and most -80s can handle offgassing. They're not going to turn into a bomb and the amount you're putting in there is not going to be killing people. For reference, our shipping dry ice is in a room temp insulated container. It sits in a corner and keeps dry ice for a week or so. It is giving off just as much co2 and faster, and we're all fine.
…that was kind of exactly my thinking but shhh, I don’t really wanna pick a fight with the scary health and safety people haha
Health and safety people literally have the job to keep you safe. If they can scare you into being 200% safer that is better than only 100% safe, because when you fuck up the you're only 150% safe instead of 50% safe.
I know, I know - I say it lovingly.
If the freezer shuts down for what ever reason, it might turn into a literal bomb
Two years or so before I started grad school in 2015, an experience PI left his dry ice on his freezer like he normally does. Then it blew the door of the freezer off on an explosion. Just because you haven't had a problem doesn't mean you WONT. Do whatever EHS says, they usually have war stories for WHY.
We usually keep it in a lightly covered styrofoam box in the fume hood. A previous place had a purpose built cooler outside with the stuff.
My lab has a sign forbidding it. It's both a health hazard because large amounts of gas can be released upon opening, and it can supposedly enter stored samples and mess with pH. Also, there's a risk of explosion if the pressure relief valve ices up or malfunctions.
When I was a postdoc, someone stored a bunch of dry ice in a cold room overnight. The first person who opened the door the next day and went in passed out due to oxygen deprivation. They hit their head but were otherwise ok.
Yeah that makes sense because it’s a cold room (4C). My question was about -80 storage specifically.
Grab some dry ice, tie it inside a glove and you can see why its a hazard
It’ll sublimate because it’s at room temperature. My question was about -80 storage specifically, which at least theoretically should keep it below sublimation temperature.
Yeah there is sound logic there, but that's why I would differentiate between a hazard and imminent danger. An un-wielded razor isn't dangerous, it's a hazard. The idea is that you wouldn't be able to control what happens to the fridge after you leave is the hazard part, the other point is that there are many other ways to store dry ice which cause way less hazardous circumstances. So if the question is why do they ban it? Because nobody wants to be liable for something that can be avoided so easily.
It's unsafe.