liquid n2 insect extermination

[dragonstar57]

would flooding a house in LN2 kill any insects in it?

where would one get bulk LN2??

Edited September 27, 2010 by cipher510

[Moontanman]

would flooding a house in LN2 kill any insects in it?

where would one get bulk LN2??

 

 

LN2?

[Cap'n Refsmmat]

Liquid nitrogen.

[Moontanman]

Then yes, lowering the temperature of the house to liquid nitrogen temps and the materials it is made of would kill all insects living there... However there are some resting eggs of arthropods that might live through the low temps, I'm not sure if any insect eggs are that tough...

[Mr Skeptic]

Some insects can survive freezing just fine. However, nitrogen can also kill by suffocation by displacing oxygen. So if you put a few semi-insulated containers of liquid nitrogen in the house, it would leave your house oxygen-free for quite a while, which would eventually kill the insects. (You it will kill quickly, and no you won't notice being short on breath).

[Moontanman]

Some insects can survive freezing just fine. However, nitrogen can also kill by suffocation by displacing oxygen. So if you put a few semi-insulated containers of liquid nitrogen in the house, it would leave your house oxygen-free for quite a while, which would eventually kill the insects. (You it will kill quickly, and no you won't notice being short on breath).

 

I'm not sure I understand, there is no difference between simply freezing something and dropping the temp to liquid nitrogen temps? A great many insects survive freezing temps in the winter, mostly by hibernating someplace where the temps do not fall completely below freezing, sometimes by producing antifreeze type chemicals in their bodies but i am sure liquid nitrogen temps is far below the antifreeze can cope with.

[Mr Skeptic]

Oh, I meant actual freezing, not just freezing temperatures. Once frozen, lowering the temp more doesn't really change much, and would probably be beneficial since it would slow down any reactions that are still occurring.

 

mm, bugsicles.

[dragonstar57]

Some insects can survive freezing just fine. However, nitrogen can also kill by suffocation by displacing oxygen. So if you put a few semi-insulated containers of liquid nitrogen in the house, it would leave your house oxygen-free for quite a while, which would eventually kill the insects. (You it will kill quickly, and no you won't notice being short on breath).

and why do you assume i will be there?

[Moontanman]

Oh, I meant actual freezing, not just freezing temperatures. Once frozen, lowering the temp more doesn't really change much, and would probably be beneficial since it would slow down any reactions that are still occurring.

 

mm, bugsicles.

 

I disagree, antifreeze type chemicals lower the temp that freezing occurs and that ice crystals form but they do not prevent it completely and once the temps fall low enough the "bug" would freeze with all the resulting problems of ice crystals and cell destruction. Liquid nitrogen temps are plenty cold enough to over come any natural antifreeze...

[Mr Skeptic]

Oh, it depends on how quickly you can set it up and how quickly it is evaporating, and how much ventilation in the house. If you faint it's game over.

[Moontanman]

I don't know about nitrogen but helium will over come you quite quickly, I remember many many many years ago when my sons were in grade school being at an event where i was giving out helium balloons and filling them on order from a cylinder and amusing the kids by talking in the high pitched voice by breathing in helium and i almost passed out in front of several dozen kids. It put me on my butt, very emabarrassing.....

[insane_alien]

you might have some problems with how the structure survive the extreme cooling. buildings tend to be made of lots of materials with different thermal expansion coefficients. you might find something breaks from the stresses created.

[CharonY]

In addition you would need enormous amounts to cool something the size of a house significantly. Cooling it down to liquid N2 temps is of course impossible but even getting close to it would require literally flooding the house in it. Most likely you could suffocate the insects, however many can survive lack of oxygen for quite a while.

[dragonstar57]

what if it was a localized cooling?

like just the carpet or the bedding?

would A quick douse in LN2 kill the bugs (if any (larva and egg)) present?

[BurningKrome]

It would probably kill your electrical work too. Try orthoboric acid instead.

[insane_alien]

why would it kill your elctrical work?

 

if anything electronics would run better

[dragonstar57]

what about filling the house with carbon monoxide?

that would kill everything there.

[CaptainPanic]

what about filling the house with carbon monoxide?

that would kill everything there.

Your neighbors will love you for it... but most likely you will get arrested for not having a permit. CO is toxic, odourless, colorless. Don't mess around with it. You die faster than the bugs.

 

I think that setting your house on fire would also kill the bugs... but like the CO plan it is a bad idea.

 

Btw, what the hell can be so bad that normal bug sprays wouldn't work? Or maybe I should ask: are we dealing with a theoretical issue - and just doing some brain exercise, or is there a practical issue which just needs to be solved in the most efficient way?

 

In other words: what are the boundary conditions to the solution you want from us?

[Mr Skeptic]

The nice thing about using liquid N2 is that it is non-toxic and all noticeable traces of it will be gone as soon as you ventilate, unlike bug spray. Using CO2 is probably even better since it can be sprinkled as a solid, and since a smaller concentration is needed to kill and it will kill quicker (the CO2 displaces O2 in the blood).

 

Using CO would be a very bad idea as you might kill your neighbors or yourself. Also some of it may stay longer than you'd think in a porous substance or poorly ventilated spaces, and while that wouldn't matter with a non-toxic gas. for CO it would.

[Klaynos]

Any pure gas breathed in will knock you out nearly immediately, this is because you are tipping the difference in o2 from being more o2 in your lungs than your blood to more o2 being in the blood than your lungs so the "air" in your lungs sucks the oxygen out of the blood flow...

 

We do a cryogens course at the start of doing phd's here, where one of the things we're made to work out is the amount of liquid nitrogen it'd take to displace all of the air in a lift if it all evaporated quickly (which is quite likely if you say knock the bottle over and it fills the flood). The maths is quite simple, give it a go...

 

We also do a couple of tricks for people on open days and other things which range from pouring a small amount of liquid nitrogen into a pringles tube and popping the top to putting some in a 2l coke bottle dropping it in a bin full of water and running away... both impress.

[John Cuthber]

Since CO is flammable there's every chance you could poison yourself then destroy the evidence with a house-fire.

If that's the plan, then you might want to consider using liquid hydrogen cyanide which, in addition to being very toxic and seriously flammable, is also explosively unstable.

 

A less extraordinarily stupid idea would be bug spray.

[dragonstar57]

just looking for a cheep way to solve a "theoretical" problem

because even "thought" problems have B) "theoretical" B) budgets

[CharonY]

The nice thing about using liquid N2 is that it is non-toxic

 

Just want to emphasize Klayno's point. N2 is all but harmless, especially in badly ventilated rooms. There have been a few reported deaths due to asphyxiation. At least two were graduated students prepping samples or filling containers with liquid nitrogen for transport.

[dragonstar57]

but would 30-40 degrees below not be enough to kill all the bugs

 

Oh, it depends on how quickly you can set it up and how quickly it is evaporating, and how much ventilation in the house. If you faint it's game over.

time until canisters are opened and first breath of nitrogen gas 30 seconds time to get out of house roughly 15 seconds

things are looking good

[Mr Skeptic]

Incidentally, breathing pure nitrogen will remove oxygen from your lungs, which is worse than holding your breath, and in addition you won't feel out of breath because your body measures CO2 not oxygen.

 

I think that if anyone truly wants to try this method they should have some portable oxygen.