Method Exit bag and inert gas megathread

[winterparty]

Would these EWOT masks work? How does the CO2 get let out? Where does that go?

Hi I think they would be less comfortable than a eebd hood if you were to ask me because you can pre-fill a hood with nitrogen and shorten the length of time till you're unconscious. If you need any help I'm still alive and can help you

 

[ClownWorld2023]

Would these EWOT masks work? How does the CO2 get let out? Where does that go?

Are those things expensive?

What price range are we talking about?

 

[RazorWing]

Hello, I am from the UK. I have been reading a number of threads on this site about the Exit Bag, SCBA and EEBD. I have been able to identify where I can purchase the equipment to make the exit bag and a nitrogen cylinder is really easy to obtain without anyone asking questions. I am now exploring SCBA as I would be more comfortable wearing a mask than covering my head with an exit bag or EEBD.

I may have missed it but is it down to choice as to if someone chose SCBA over EEBD or is EEBD safer? There seems to be allot of discussion regarding EEBD which leads me to believe it maybe a more recommended approach.

In the UK the cylinder has a BSP 5/8 connection and the regulator has a BSP 5/8 to BSP 3/8 as pictured. For the exit bag approach I was going to get a 3 meter BSP 3/8 extension hose and tape it inside the bag. It sounds as if this would work and would mean the fitting on both the regulator, cylinder and hose would be tightly secure. Please let me know if you see any issues with this?

For the other two methods it doesn't seem as straightforward although I would prefer them over making my own bag. Branded SCBA/EEBD seems to be really pricey as noted by others and I am really struggling to find Chinese versions of the mask/hood. Can anyone assist with sources? Also it looks more difficult extending the hose or connecting it to the BSP 3/8 connector. Any advice?

 

[ClownWorld2023]

Hello, I am from the UK. I have been reading a number of threads on this site about the Exit Bag, SCBA and EEBD. I have been able to identify where I can purchase the equipment to make the exit bag and a nitrogen cylinder is really easy to obtain without anyone asking questions. I am now exploring SCBA as I would be more comfortable wearing a mask than covering my head with an exit bag or EEBD.

I may have missed it but is it down to choice as to if someone chose SCBA over EEBD or is EEBD safer? There seems to be allot of discussion regarding EEBD which leads me to believe it maybe a more recommended approach.

In the UK the cylinder has a BSP 5/8 connection and the regulator has a BSP 5/8 to BSP 3/8 as pictured. For the exit bag approach I was going to get a 3 meter BSP 3/8 extension hose and tape it inside the bag. It sounds as if this would work and would mean the fitting on both the regulator, cylinder and hose would be tightly secure. Please let me know if you see any issues with this?

For the other two methods it doesn't seem as straightforward although I would prefer them over making my own bag. Branded SCBA/EEBD seems to be really pricey as noted by others and I am really struggling to find Chinese versions of the mask/hood. Can anyone assist with sources? Also it looks more difficult extending the hose or connecting it to the BSP 3/8 connector. Any advice?

Hi,

I highly recommend getting your post count up so you can use the search function.
This thread is full of valuable information, but some of the information is also scattered around in other threads which are too difficult to find by just browsing.
You really need to use the search function to find the information you want.
It may take hours or even days of thoroughly searching to find all the information you need, but it should be there.




As for your questions, I have some quick answers:

- EEBD is preferred over the plastic exit bag, because generally it's more reliable. The EEBD hood is pre-made and uses durable material compared to the plastic bags.
Also, the EEBD hoods have an exhale valve for getting rid of the carbon dioxide. The carbon dioxide buildup should be much less of a problem compared to the plastic bag, which relies on the displacement of the carbon dioxide using the gas flow.


- SCBA has an important advantage over both the plastic bag/EEBD methods, and that is the significantly reduced gas consumption. Gas is only supplied by the demand valve when necessary (as you breathe in/out), instead of a continuous supply.
This significantly reduces the gas needed, making the method slightly more accessible, because you can use a smaller gas cylinder which is easier to handle and transport.
There might be other advantages I don't know of.

- Chinese EEBD hoods can be found relatively cheap on Alibaba, but I don't know about the quality.

 

[Dmoore3232]

Are those things expensive?

What price range are we talking about?

Like $150 I think, why? would it work?

 

[ClownWorld2023]

Like $150 I think, why? would it work?

If it can seal the face properly without leaks, and has an exhalation valve, maybe?

I don't know anything about that type of mask.

You will need to figure out whether you can connect this to a gas cylinder.
First you need to lookup the specifications, data sheets, manual, etc...

 

[ztem]

Would these EWOT masks work?

Not viable.There are much better setups like Hood/SCBA/SCUBA.

In the UK the cylinder has a BSP 5/8 connection and the regulator has a BSP 5/8 to BSP 3/8 as pictured. For the exit bag approach I was going to get a 3 meter BSP 3/8 extension hose and tape it inside the bag. It sounds as if this would work and would mean the fitting on both the regulator, cylinder and hose would be tightly secure. Please let me know if you see any issues with this?

A side entry regulator would be better.

SCBA/EEBD

~1600£/less than 500£

extending the hose or connecting it to the BSP 3/8 connector

For that you just need 3 hose clamps and a hose barb and double-ended hose barb
and an air hose with 1/4" ID but you don't need to do that, just buy the 3M Scott + Rectus 95KS coupler (with G3/8 female thread).

 

[MG_39]

Edit: According to the gas consumption I estimate, that I breathed Nitrogen for one minute or one and a half minute.

What did you use? bag, eebd? 1-1.5min without losing consciousness sounds like a long time :/

 

[winterparty]

What do you think of doing this method when you're sick? I know I'm coughing a lot and my breathing is a little bit off. This won't trigger some response though and it might take more time till you become unconscious as far as I understand? Or is there the possibility of a hypercapnic response? And where will the co2 leave if you use eebd hood? I'm just curious.

 

[Falling Slowly]

And where will the co2 leave if you use eebd hood? I'm just curious.

I saw a previous post of yours saying you have the Scott ELSA hood, which I also have. While there's an exhalation valve on it, it's not great. There's also 2 small holes in the inner mask(see pic below), which I presume are to let the air go into the hood itself.
Are you worried about too much CO2 getting into the hood and not going out the exhalation valve?

 

[Mare Imbrium]

Our important fellows Gas Monkey and Das Nichts - they are no longer here and are very missed. Did they ctb?

 

[Falling Slowly]

Our important fellows Gas Monkey and Das Nichts - they are no longer here and are very missed. Did they ctb?

Not sure, I haven't seen anyone say for certain. Several people have presumed that @GasMonkey has ctb as it's unlikely he'd be off the site for this long.
I'm not sure about @Das Nichts, I haven't heard anything about him.

 

[ClownWorld2023]

What do you think of doing this method when you're sick? I know I'm coughing a lot and my breathing is a little bit off. This won't trigger some response though and it might take more time till you become unconscious as far as I understand? Or is there the possibility of a hypercapnic response? And where will the co2 leave if you use eebd hood? I'm just curious.

The PPH says the method may not be suitable if you have any lung diseases.
There are two entire pages dedicated to it. (PPH, 2021 August, pages 56-57).

Spirometry testing can be done for quick screening.
I don't know whether this can be done at home, and if so, whether the result is reliable enough.

 

[ClownWorld2023]

While there's an exhalation valve on it, it's not great.

Out of curiosity, what issue are you having with the valve of that hood? Is it not working at all?

 

[Falling Slowly]

Out of curiosity, what issue are you having with the valve of that hood? Is it not working at all?

When I exhale deeply with the hood on, I feel a small amount of air going out the front of the valve, but some goes into the hood, especially via the two small holes in the inner mask The holes are probably there to let oxygen flow into the hood, I think maybe I should seal off those holes with tape.

Maybe when there's nitrogen flowing in the hood there will be a pressure against the valve and the CO2 might flow out the valve easier. But it's not a high tech exhale valve or anything. I took the valve apart, and it's basically just a circular piece of plastic against a spring. The exhaled air pushes against the plastic, which pushes against the spring, leaving a gap for exhaled air to go out.
I'm hoping if small amounts of CO2 go into the hood it won't make too much of a difference.

 

[ClownWorld2023]

When I exhale deeply with the hood on, I feel a small amount of air going out the front of the valve, but some goes into the hood, especially via the two small holes in the inner mask The holes are probably there to let oxygen flow into the hood, I think maybe I should seal off those holes with tape.

I see.

Your hood is quite expensive though. I assume it should be fine.


I myself haven't had the chance to test my EEBD hood yet, but I will do it later.
My hood came as part of an actual set. It's made in China so I don't know about the quality, but I hope it's good enough.

Right now I'm doing my best to figure out how to connect it without having to modify the hose.

Maybe when there's nitrogen flowing in the hood there will be a pressure against the valve and the CO2 might flow out the valve easier. But it's not a high tech exhale valve or anything. I took the valve apart, and it's basically just a circular piece of plastic against a spring. The exhaled air pushes against the plastic, which pushes against the spring, leaving a gap for exhaled air to go out.
I'm hoping if small amounts of CO2 go into the hood it won't make too much of a difference.

If you happen to have a diving cylinder or compressed gas cylinder (clean air, not contaminated) you could test it I suppose.

If it was still summer in my area I would've tried this myself, but I think it would be suspicious to get a diving gas cylinder refilled, consider almost no one is going to go diving in this weather.

 

[winterparty]

Yes. This is what I was worried about. @Falling Slowly and I have the 3M Scott hood myself which was recommended by gas monkey so I'm thinking about it.

 

[ClownWorld2023]

Yes. This is what I was worried about. @Falling Slowly and I have the 3M Scott hood myself which was recommended by gas monkey so I'm thinking about it.

There were also problems reported with the PSS hood.

Maybe it's not just those hoods, but all EEBD hoods?

I really hope that's not the case though.


Normally these hoods are used with a EEBD set that uses a relatively high flow rate of 35-40 LPM, some going even higher than that.
So it could be that the exhale valve was designed with that in mind.



Anyway, how are you guys testing the hoods?
Can you just wear it without the hose plugged onto anything and breathe in and out without issues?
Won't there be a problem because no air is being actively supplied into the hood?

 

[winterparty]

Keep in mind that @Vizzy killed himself succesfully with a eebd hood.

 

[Falling Slowly]

Anyway, how are you guys testing the hoods?
Can you just wear it without the hose plugged onto anything and breathe in and out without issues?
Won't there be a problem because no air is being actively supplied into the hood?

So far I haven't done any proper test, just breathing in and out a few times to test the exhalation valve, without the hose plugged in .

Keep in mind that @Vizzy killed himself succesfully with a eebd hood.

Yes, the EEBD hood has worked for some people, though the SCBA setup is probably more reliable.

 

[k1w1]

When I exhale deeply with the hood on, I feel a small amount of air going out the front of the valve, but some goes into the hood, especially via the two small holes in the inner mask The holes are probably there to let oxygen flow into the hood, I think maybe I should seal off those holes with tape.

Maybe when there's nitrogen flowing in the hood there will be a pressure against the valve and the CO2 might flow out the valve easier. But it's not a high tech exhale valve or anything. I took the valve apart, and it's basically just a circular piece of plastic against a spring. The exhaled air pushes against the plastic, which pushes against the spring, leaving a gap for exhaled air to go out.
I'm hoping if small amounts of CO2 go into the hood it won't make too much of a difference.

EEBD hoods become flooded with nitrogen at the recommended lpm rate. That nosepeice and valve looks fairly good compared to mine. Any exhaled gas that remains within the hood will be pushed out at the neck fitting, this is why the elasticated fitting is not 'skin-tight'. It is also why a cylinder with 40 mins flow duration is used. It is if you will excuse the pun, an overkill amount of gas, A great deal of over-thinking goes on here, which is fairly predictable under the circumstances. But when one considers that this method started out as an oven bag with a plastic tube taped inside it, these hoods with the exhalation valve are quite a remarkable development.

It's not possible to refund it, that's why I rather not.


I already found a source for the 344 coupler. The problem is it can take up to a month to get it delivered.

If you live in a city with a workplace safety shop, you can head in and try the fittings out yourself. Same with welding/pneumatic supply shops. I have one fairly close to home & those couplers are on the shelf, unboxed, sold seperately. This should put your mind at rest.

 

[ClownWorld2023]

If you live in a city with a workplace safety shop, you can head in and try the fittings out yourself. Same with welding/pneumatic supply shops. I have one fairly close to home & those couplers are on the shelf, unboxed, sold seperately. This should put your mind at rest.

I went with the 95 KS coupler instead.
I understood that only the 344 series would work, because the 341 and 342 series were not compatible length-wise.
That's what customer support told me.

But anyway, I decided to no longer use that hood, because other members had problems with the exhalation valve.

---

I managed to remove the hose from my EEBD set's pressure reducer, but I don't recognize this male connector.

Does anyone know what it is?
Thread diameter seems to be 8-9mm.

I looked up the thread size charts, but I didn't understand them.

 

[winterparty]

This scared me quite a bit. The hood setup is not 100% reliable? Can a hypercapnic alarm occur? Can someone explain further?

 

[ClownWorld2023]

This scared me quite a bit. The hood setup is not 100% reliable? Can a hypercapnic alarm occur? Can someone explain further?

Two members mentioned the PSS hood exhalation valve not letting out air during exhale.

I'm not sure whether there are other hoods with this issue.


I will wear and test my hood tomorrow.

 

[Dmoore3232]

Will all nitrogen tank hoses attach to this eebd hood? Also is there a standard hose for nitrogen tanks?

 

[Falling Slowly]

I went with the 95 KS coupler instead.

---

I managed to remove the hose from my EEBD set's pressure reducer, but I don't recognize this male connector.

Does anyone know what it is?
Thread diameter seems to be 8-9mm.

I looked up the thread size charts, but I didn't understand them.


View attachment 121405

You'll probably have to either cut the connector off, and hook the hose directly to a regulator connection, if the hose is long enough, and fits. (Using a hose clamp).

Or, seeing as you say that you have a Rectus 95 ks coupling, you have the option of getting an extension hose like this, attaching your hose to that, and plugging it directly into the coupling (that Scott 3m hose will fit that coupling).
Or get just the male hose nipple barb thats used on that extension hose, and put it into your hose. Then plug it into the Rectus coupling.

Will all nitrogen tank hoses attach to this eebd hood? Also is there a standard hose for nitrogen tanks?
View attachment 121410

You don't hook up a hood directly to a nitrogen cylinder, you have to control the flow coming from the cylinder, so you need a nitrogen (or argon) regulator.
Cylinder>>regulator>>hood.

These hoods are usually connected to an air cylinder, so there's no standard hose that connects to a nitrogen regulator.
I'm not sure what kind of hood that is in your pic, but you might be better off getting a hood with a hose attached.

 

[k1w1]

With apologies to the longer term members that are still with us, I have posted this before but Im reposting to answer the above concerns : This is mine (yeah yeah....'there are many like it etc') The hood came with a meter of attached hose & a hokey end fitting which was cut off promptly. The regulator is a wee ripper, being a dual stage with built in flow meter. The last image is the hose join that seems to strike fear into many a heart!! These hoses were the same I/D but slightly different O/D; but with a double barb joiner and ear clamps they cramp down very tight. I have tested all joins with soapy water and they effective and sound. Best wishes, now I just have to find a way of esting it without killing myself !!

 

[ztem]

two small holes in the inner mask The holes are probably there to let oxygen flow into the hood, I think maybe I should seal off those holes with tape.

The Drager Saver CF and LALIZAS have those two holes on the inner mask too , If you think those two holes are a flaw in the design of the hood, seal it.

Maybe when there's nitrogen flowing in the hood there will be a pressure against the valve and the CO2 might flow out the valve easier

There is no doubt about it.

But it's not a high tech exhale

That low tech exhalation valve will do the job, you only need an exhalation valve to prevent carbon dioxide from accumulating inside the hood, cessation of breathing occurs in less than 5 minutes, If you think that exhalation valve can't do its job for 5 minutes, you better sue the manufacturer and get some money from them.

Right now I'm doing my best to figure out how to connect it without having to modify the hose.

Yeah you need an aerospace engineering degree and years of physical and mental training to cut the end of the hose and use a hose barb and hose clamp.

though the SCBA setup is probably more reliable.

For example the reason I went with the SCBA was because the system's paper (so called money) is useless when I'm dead, so it's better to spend as much as possible for the last thing I want to spend paper on + There are 5 SCBA suppliers around my house (available immediately) , everything was available locally and the only thing I needed to buy from abroad was the adapter. The use of SCBA equipment is overkill and unnecessary imo, you just need a confined, oxygen-free space, preferably with an exhalation valve, which a hood will give you that, the SCBA is just a fancy way of doing it.

Does anyone know what it is?
Thread diameter seems to be 8-9mm.

I looked up the thread size charts, but I didn't understand them.

I sent you some adapters for that and you need to spend some money and try them, but as I said, it's better to modify the hose.

 

[winterparty]

OK now I'm confused. So the the two holes matter in terms of co2 getting inside the hood? How would you seal them?

I saw a previous post of yours saying you have the Scott ELSA hood, which I also have. While there's an exhalation valve on it, it's not great. There's also 2 small holes in the inner mask(see pic below), which I presume are to let the air go into the hood itself.
Are you worried about too much CO2 getting into the hood and not going out the

I saw a previous post of yours saying you have the Scott ELSA hood, which I also have. While there's an exhalation valve on it, it's not great. There's also 2 small holes in the inner mask(see pic below), which I presume are to let the air go into the hood itself.
Are you worried about too much CO2 getting into the hood and not going out the exhalation valve?

View attachment 121336

 

[Dmoore3232]

You'll probably have to either cut the connector off, and hook the hose directly to a regulator connection, if the hose is long enough, and fits. (Using a hose clamp).

Or, seeing as you say that you have a Rectus 95 ks coupling, you have the option of getting an extension hose like this, attaching your hose to that, and plugging it directly into the coupling (that Scott 3m hose will fit that coupling).
Or get just the male hose nipple barb thats used on that extension hose, and put it into your hose. Then plug it into the Rectus coupling.

You don't hook up a hood directly to a nitrogen cylinder, you have to control the flow coming from the cylinder, so you need a nitrogen (or argon) regulator.
Cylinder>>regulator>>hood.

These hoods are usually connected to an air cylinder, so there's no standard hose that connects to a nitrogen regulator.
I'm not sure what kind of hood that is in your pic, but you might be better off getting a hood with a hose attached.

Damn, I could almost just run a hose under that like an old school exit bag. You need another hose for air to get out though right?