# Is it dangerous to let dry ice subliminate inside the house?
**URL:** https://boards.straightdope.com/t/is-it-dangerous-to-let-dry-ice-subliminate-inside-the-house/1002200
**Category:** Factual Questions
**Created:** [May 28, 2024, 10:05pm UTC](https://boards.straightdope.com/t/is-it-dangerous-to-let-dry-ice-subliminate-inside-the-house/1002200 "2024-05-28T22:05:56Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@Velocity](https://boards.straightdope.com/u/Velocity)
#### Post date: [May 28, 2024, 10:05pm UTC](https://boards.straightdope.com/t/is-it-dangerous-to-let-dry-ice-subliminate-inside-the-house/1002200/1 "2024-05-28T22:05:56Z")
I get food deliveries to my home, and in the past, when the delivery involved a big package of dry ice, I just let it subliminate away inside the house.
Is this a risk for putting too much CO2 in the house air? Never thought about it before until today.
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### Author:  [@Skywatcher](https://boards.straightdope.com/u/Skywatcher)
#### Post date: [May 28, 2024, 10:14pm UTC](https://boards.straightdope.com/t/is-it-dangerous-to-let-dry-ice-subliminate-inside-the-house/1002200/2 "2024-05-28T22:14:10Z")
> [@Velocity](#):
>
> Is this a risk for putting too much CO2 in the house air?
It depends on how well the immediate area is ventilated.
[https://www.grainger.com/know-how/safety-health/management/kh-tips-handling-dry-ice-safely](https://www.grainger.com/know-how/safety-health/management/kh-tips-handling-dry-ice-safely)
> **Q: Can dry ice cause carbon dioxide poisoning?**
>
> **A** : Dry ice can produce large quantities of carbon dioxide as it turns from a solid to a gas. Carbon dioxide is in the air we breathe, but it makes up only a tiny percentage of it (less than a tenth of one percent), and at high concentrations it has toxic effects. Carbon dioxide poisoning can be caused by dry ice in enclosed, poorly ventilated spaces.
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### Author:  [@nearwildheaven](https://boards.straightdope.com/u/nearwildheaven)
#### Post date: [May 28, 2024, 10:26pm UTC](https://boards.straightdope.com/t/is-it-dangerous-to-let-dry-ice-subliminate-inside-the-house/1002200/3 "2024-05-28T22:26:33Z")
As long as you handle it with tongs, or pour it into the sink or another container, and the area is well ventilated, you should be fine.
The biggest hazard of dry ice is actually frostbite.
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### Author:  [@Folly](https://boards.straightdope.com/u/Folly)
#### Post date: [May 28, 2024, 10:49pm UTC](https://boards.straightdope.com/t/is-it-dangerous-to-let-dry-ice-subliminate-inside-the-house/1002200/4 "2024-05-28T22:49:09Z")
It wouldn’t be the worst idea to let it sublimate outside if that’s an option.
While the body has a strong carbon dioxide suffocation alarm system (and famously not a lack of oxygen alarm system), it isn’t foolproof and weird circumstances have led to dry ice causing deaths.
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### Author:  [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)
#### Post date: [May 28, 2024, 11:00pm UTC](https://boards.straightdope.com/t/is-it-dangerous-to-let-dry-ice-subliminate-inside-the-house/1002200/5 "2024-05-28T23:00:42Z")
> [@Folly](#):
>
> It wouldn’t be the worst idea to let it sublimate outside if that’s an option.
Agreed that it shouldn’t be a problem in a well-ventilated area but I would recommend putting it outside for safety. Alternatively, you could do [one of these things](https://www.thoughtco.com/cool-dry-ice-projects-606405) with it, although you should be very careful about putting it into a container and sealing it to make a “bomb”; even in plastic it can develop enough pressure to be a moderate hazard, and it can freeze polypropylene hard enough that it will be sharp enough to easily cut skin.
Stranger
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### Author:  [@markn\_1](https://boards.straightdope.com/u/markn_1)
#### Post date: [May 29, 2024, 12:33am UTC](https://boards.straightdope.com/t/is-it-dangerous-to-let-dry-ice-subliminate-inside-the-house/1002200/6 "2024-05-29T00:33:06Z")
[There was a case](https://abcnews.go.com/US/woman-dies-dry-ice-back-car-seattle/story?id=56937163) a few years ago in which a person died of suffocation from exposure to sublimating dry ice, but it was in a car, not in a house. It seems unlikely to be a problem in a large well-ventilated room, but I play it safe and always put dry ice outdoors (when I’m finished playing with it in the sink).
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### Author:  [@Balthisar](https://boards.straightdope.com/u/Balthisar)
#### Post date: [May 29, 2024, 2:00am UTC](https://boards.straightdope.com/t/is-it-dangerous-to-let-dry-ice-subliminate-inside-the-house/1002200/7 "2024-05-29T02:00:25Z")
For what it’s worth, emptying 20 pounds of CO2 into my basement by mistake didn’t hurt anyone. Well, me, via my pocketbook (about $20).
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### Author:  [@needscoffee](https://boards.straightdope.com/u/needscoffee)
#### Post date: [May 29, 2024, 2:05am UTC](https://boards.straightdope.com/t/is-it-dangerous-to-let-dry-ice-subliminate-inside-the-house/1002200/8 "2024-05-29T02:05:52Z")
> [@markn\_1](#):
>
> [There was a case](https://abcnews.go.com/US/woman-dies-dry-ice-back-car-seattle/story?id=56937163) a few years ago in which a person died of suffocation from exposure to sublimating dry ice, but it was in a car, not in a house.
They both ended up dying. So sad.
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### Author:  [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)
#### Post date: [May 29, 2024, 2:24am UTC](https://boards.straightdope.com/t/is-it-dangerous-to-let-dry-ice-subliminate-inside-the-house/1002200/9 "2024-05-29T02:24:28Z")
Related note: there’s a myth that sleeping in the same room as house plants can cause CO2 toxicity because plant respiration at night releases CO2 instead of taking it in as they do during photosynthesis.
The reality is that the amount of CO2 produced by plants is minimal compared to, say, another human sleeping next to you and will not be harmful. There supposedly was once a test conducted by NASA in a greenhouse (something to do with determining what plants might contribute to gases in a closed system in space) and the person(s) in the greenhouse didn’t suffocate at night.
I worry just a bit about passing by my potted pitcher plants and accidentally falling into one of their bug-catching receptacles, but am not concerned about horticultural carbon dioxide poisoning.
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### Author:  [@Bosda\_Di\_Chi\_of\_Tricor](https://boards.straightdope.com/u/Bosda_Di_Chi_of_Tricor)
#### Post date: [May 29, 2024, 2:33am UTC](https://boards.straightdope.com/t/is-it-dangerous-to-let-dry-ice-subliminate-inside-the-house/1002200/10 "2024-05-29T02:33:59Z")
Could you use Dry Ice as an insecticide?
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### Author:  [@needscoffee](https://boards.straightdope.com/u/needscoffee)
#### Post date: [May 29, 2024, 2:36am UTC](https://boards.straightdope.com/t/is-it-dangerous-to-let-dry-ice-subliminate-inside-the-house/1002200/11 "2024-05-29T02:36:24Z")
> [@Bosda\_Di\_Chi\_of\_Tricor](#):
>
> Could you use Dry Ice as an insecticide? -
I vaguely remember using CO2 to kill the Madagascar cockroches before dissection in college back in 1978, though I may be misremembering…but I think that’s right.
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### Author:  [@DrDeth](https://boards.straightdope.com/u/DrDeth)
#### Post date: [May 29, 2024, 2:36am UTC](https://boards.straightdope.com/t/is-it-dangerous-to-let-dry-ice-subliminate-inside-the-house/1002200/12 "2024-05-29T02:36:43Z")
> [@Jackmannii](#):
>
> I worry just a bit about passing by my potted pitcher plants and accidentally falling into one of their bug-catching receptacles,
Either you are very small, or your plants are gigantic!
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### Author:  [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)
#### Post date: [May 29, 2024, 2:39am UTC](https://boards.straightdope.com/t/is-it-dangerous-to-let-dry-ice-subliminate-inside-the-house/1002200/13 "2024-05-29T02:39:50Z")
> [@Balthisar](#):
>
> For what it’s worth, emptying 20 pounds of CO2 into my basement by mistake didn’t hurt anyone.
That could be risky if you have a pet or small child (or even an adult under the wrong conditions). CO2 is ~2 kg/m^3, so 10 kg makes for 5 m^3. That would cover the bottom 20 cm of a 250 ft^2 / 25 m^2 room. The gas isn’t going to mix very well, and anything breathing from a low height could easily suffocate.
It could even be a problem in a small apartment with well-sealed doors, but a small basement could be especially dangerous.
Not a problem for just a couple of pounds, though.
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### Author:  [@needscoffee](https://boards.straightdope.com/u/needscoffee)
#### Post date: [May 29, 2024, 2:50am UTC](https://boards.straightdope.com/t/is-it-dangerous-to-let-dry-ice-subliminate-inside-the-house/1002200/14 "2024-05-29T02:50:51Z")
> [@Dr.Strangelove](#):
>
> That could be risky if you have a pet or small child
You reminded me of when my sister inadvertently let a Teflon-coated pan of water boil dry, and a dozen or more pet lovebirds succumbed to the fumes.
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### Author:  [@kayaker](https://boards.straightdope.com/u/kayaker)
#### Post date: [May 29, 2024, 12:07pm UTC](https://boards.straightdope.com/t/is-it-dangerous-to-let-dry-ice-subliminate-inside-the-house/1002200/15 "2024-05-29T12:07:53Z")
Long story, but I once transported a dewar of liquid nitrogen in my car. It was seat-belted in the passenger seat. When I hit a pothole, it would jiggle the dewar enough to release a small cloud.
All went well, I never even considered the risk until later.
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### Author:  [@Shalmanese](https://boards.straightdope.com/u/Shalmanese)
#### Post date: [May 29, 2024, 12:54pm UTC](https://boards.straightdope.com/t/is-it-dangerous-to-let-dry-ice-subliminate-inside-the-house/1002200/16 "2024-05-29T12:54:20Z")
To quantify in a very rough sense:
A typical bedroom/office might be roughly 3m x 3m x 3m or ~30 cubic meters
30 m^3 \* the density of air = ~40kg
Typical outdoor CO2 levels are ~400ppm and indoor is 400 - 1000ppm therefore ~16 - 40 grams of CO2 are currently present in that room.
Every 40g (~1.5oz) of dry ice you let sublimate adds another 1000ppm to the room (assuming zero ventilation).
_Health effects_ of CO2 are detectable as low as [1000ppm](https://learn.kaiterra.com/en/resources/carbon-dioxide-co2) to [10,000ppm](https://www.fsis.usda.gov/sites/default/files/media_file/2020-08/Carbon-Dioxide.pdf) depending on who you listen to but _serious danger_ tends to be in the [~100,000 ppm](https://nap.nationalacademies.org/read/11170/chapter/5) range.
So 4kg (10lb) of dry ice would possibly kill you, 400g (1lb) would definitely start causing health issues and as little as an ounce or two would cause a sharp spike on CO2 levels, leading to feelings of the room being stuffy and drowsiness/fatigue/lack of clear thinking.
I was surprised going through the math as I thought a few ounces were generally harmless but I’ll make sure to let my dry ice packs vent outdoors from now on. Still, anyone with a gallon jug sized chunk of dry ice should hopefully know to take appropriate precautions and ventilate from a pure common sense perspective.
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### Author:  [@asterion](https://boards.straightdope.com/u/asterion)
#### Post date: [May 29, 2024, 1:24pm UTC](https://boards.straightdope.com/t/is-it-dangerous-to-let-dry-ice-subliminate-inside-the-house/1002200/17 "2024-05-29T13:24:02Z")
The nice thing about dry ice is that you will know if the concentration of local CO2 is increasing to any significant degree because we evolved to sense carbon dioxide in higher amounts. The risk will depend on total amount (44 g sublimates to 22.4 L gas), rate of sublimation, overall ventilation and air turnover, size of room, and so on. Probably best to stick it outside if you’re at all worried but if you’ve never noticed anything before you’re fine.
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### Author:  [@jjakucyk](https://boards.straightdope.com/u/jjakucyk)
#### Post date: [May 29, 2024, 8:44pm UTC](https://boards.straightdope.com/t/is-it-dangerous-to-let-dry-ice-subliminate-inside-the-house/1002200/18 "2024-05-29T20:44:58Z")
> [@asterion](#):
>
> The nice thing about dry ice is that you will know if the concentration of local CO2 is increasing to any significant degree because we evolved to sense carbon dioxide in higher amounts.
That wouldn’t seem to be the case with those women who died in a car because of it.
I recall a similar story that may very well have been told here in another thread. A group of people were going on a trip, and they had a big cooler of food with dry ice in the back of the SUV. It was hot out so they had the a/c on, and crucially, in air recirculating mode. They all started to get very drowsy after a while, and when someone realized what was happening, opened a window and then everyone perked right back up. That’s a scary close call, because the reaction was just to get tired. That’s basically what happens with carbon MONoxide poisoning too.
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### Author:  [@Dr\_Paprika](https://boards.straightdope.com/u/Dr_Paprika)
#### Post date: [May 29, 2024, 9:17pm UTC](https://boards.straightdope.com/t/is-it-dangerous-to-let-dry-ice-subliminate-inside-the-house/1002200/19 "2024-05-29T21:17:33Z")
You need to worry if your plant starts singing “Feed me, Seymour”.
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### Author:  [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)
#### Post date: [May 29, 2024, 9:23pm UTC](https://boards.straightdope.com/t/is-it-dangerous-to-let-dry-ice-subliminate-inside-the-house/1002200/20 "2024-05-29T21:23:34Z")
Just remember that CO2 is heavier than air (molecular wt 44 compared to air that averages around 29 so it settles. There was a story about a town in, IIRC, Africa that suffocated when a giant bubble of CO2 came out of a lake and settled on the town.
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