Discussion Inert gas methods comparison

[sucktobeagdguy]

Hi,

First of all English is not my native language so apologies for any mistakes in advance.

I have been looking into the inert gas methods (exit bag, eebd, scuba & scba) on this forum for the past few days, and I want to summaries the pro and con of each method (based on what I understand) and see if anyone agrees, please share your thoughts and discuss which method is more reliable.

Exit bag:
Pros:
- parts can be gathered very easily
- cheapest and quite easy to setup

Cons:
- lots of uncertainties, bag could be blown off due to high pressure, the person could tear off the bag due to SI, slight movement after becoming unconscious could break the seal and let oxygen get inside the bag
- high failure rate for unknown reasons


Eebd hood:
Pros:
- much more sturdy than exit bag
- movement after becoming unconscious will unlikely interrupt the process
- cost more than making an exit bag but not as expensive as scuba and scba

Cons:
- the most well known yellow chinese eebd hood seems to have quality issues resulting in unsuccessful ctb
- some other hoods such as drager eebd hood don't have an exhaustion valve, so whether they are suitable for the inert gas method is still unknown
- quite difficult to set up as you need to extend and cramp the hose, and that might cause leaks


Scuba mask:
Pros:
- fairly easy to setup and source the parts
- tightly secured on your face so any movement after becoming unconscious will unlikely interrupt the process
- it uses 1st and 2nd stage regulator to control the flow, so gas will only flow in when the person inhale through the 2nd stage regulator, resulting in less gas usage and faster unconscious time

Cons:
- parts are very expensive
- it uses np (negative pressure) so the breathing resistance is higher, there are concerned about whether the weaker breath after becoming unconscious is enough to pop open the valve and keep the airflow (however, the breathing resistance of some 2nd stage regulators can be adjusted)


Scba mask:
Pros:
- Appears to be the most reliable method if you can obtain the parts
- it works similar to scuba but uses pp (positive pressure) instead, so the breathing resistance is very low, keeping airflow after becoming unconscious shouldn't be an issue

Cons:
- not much info regarding how to setup and source parts
- very difficult to source parts (I can only find pre-owned parts in the UK)
- also very expensive


I think scba will be too difficult to adapt for many of us, so out of the other 3 (exit bag, eebd & scuba), which one do you think is the most reliable method?

 

[Crescendo]

I think your assessment is largely correct. I have a few things to add to your pros & cons list, though keep in mind some of these are subjective.

Exit bag:
- While it may be reportedly easy to setup by some, others claimed having trouble constructing the bag as it takes some precision and that the tutorial isn't as easy to follow as 1-2-3.
- It's possible exhaled CO2 may not be properly flushed out by the flow of inert gas, unlike with an exhalation valve or other dedicated way of removing CO2.
+ No potential concern of unresponsive exhalation/inhalation valves when user goes unconscious, which seems to be a potential point of concern for the commercial breathing apparatuses.

SCBA:
Regarding setup and sourcing, have you read GasMonkey's setup thread - https://sanctioned-suicide.net/threads/gasmonkey-setup-nitrogen-scba.115434/? Lot of good info including mention of brands and sources later down the pages. Gasmonkey confirmed the name of the mask + regulator/ldv he used here btw: https://sanctioned-suicide.net/threads/exit-bag-and-inert-gas-megathread.8393/post-2017712.

I was able to find a supplier who sold full scba gear first-hand (factory new) in the US. I believe they also ship internationally. No need to register as a company to make a purchase or anything like that. But yes it is quite expensive. Idk if buying second-hand is safe or not, it very likely could be fine, but it's not something I wanted to risk.

 

[sucktobeagdguy]

I think your assessment is largely correct. I have a few things to add to your pros & cons list, though keep in mind some of these are subjective.

Exit bag:
- While it may be reportedly easy to setup by some, others claimed having trouble constructing the bag as it takes some precision and that the tutorial isn't as easy to follow as 1-2-3.
- It's possible exhaled CO2 may not be properly flushed out by the flow of inert gas, unlike with an exhalation valve or other dedicated way of removing CO2.
+ No potential concern of unresponsive exhalation/inhalation valves when user goes unconscious, which seems to be a potential point of concern for the commercial breathing apparatuses.

SCBA:
Regarding setup and sourcing, have you read GasMonkey's setup thread - https://sanctioned-suicide.net/threads/gasmonkey-setup-nitrogen-scba.115434/? Lot of good info including mention of brands and sources later down the pages. Gasmonkey confirmed the name of the mask + regulator/ldv he used here btw: https://sanctioned-suicide.net/threads/exit-bag-and-inert-gas-megathread.8393/post-2017712.

I was able to find a supplier who sold full scba gear first-hand (factory new) in the US. I believe they also ship internationally. No need to register as a company to make a purchase or anything like that. But yes it is quite expensive. Idk if buying second-hand is safe or not, it very likely could be fine, but it's not something I wanted to risk.

Thanks for sharing the info regarding SCBA, I read gasmonkey's setup thread but didn't know he confirmed the equipment that he used on the megathread, guess I didn't look deep enough.

And I do agree with your pros and cons as well as they are also my concerns. Making the seal too loose will risk letting oxygen flow into the bag, while making the seal too tight will cause the problem that you suggested, the key is to find the perfect tightness which is one of the most crucial and challenging part of the exit bag method.

Also it seems I can't edit my post anymore but I would like to add one more con for the eebd hood:
- require a minimum of 25lpm airflow, so you will be running out of gas a lot faster and this can be a huge risk if you don't have a large tank