Sciencemadness Discussion Board

gas mask for NO2

cartoonkitty - 3-8-2006 at 17:14

I need to do experiments with NO2, can anybody recommend an appropriate gas mask. What concentration of NO2 can a gas mask resist? If I use 1000ppm NO2, wearing gas mask is good enough?

YT2095 - 4-8-2006 at 01:36

I use an British Army Avon S10 full face gas mask with NBC filters (Israeli).
nothing gets through it!

I`ve sat in a room Full of Ammonia gas enough to knock you on your ass and temp blind you, I never smelled a thing, same with Chlorine, Nada :)

evil_lurker - 4-8-2006 at 08:47

Keep in mind that gas masks are prone to breakthru... and if your gas mask fails at a bad time it might be your ass depending on what your working with.

Plus the cartridges are not cheap to replace.

I prefer to use an airline respirator manufactured by MSA (same ppl that manufacture firefighter air packs) connected to a remote compressor for working with nasty chemicals.

garage chemist - 4-8-2006 at 13:09

I prefer to work under the fume hood! Gas mask is unnecessary then.
I think a gas mask is not a good solution for working with dangerous gases in the lab, since the gases can contaminate the entire air without you noticing.
With a fume hood, the gases are immediately vented outside. I think that this is way better.
You don't have to worry about filter lifetime.

In german forums, almost nobody uses gas masks. Everyone prefers fume hoods.

unionised - 6-8-2006 at 01:03

Why not design the experiment to trap the NO2 rather than venting it to the atmosphere?
in general,it's better to controll problems at the source.

YT2095 - 6-8-2006 at 07:41

I couldn`t agree more with the fume hood ideal, but sometimes it`s not always available or Sh!t hits the fan (no pun intended) and it`s nice to have a Well tested Backup mask to grab for.

Beter to Have and not need, than to Need and not have! ;)

franklyn - 6-8-2006 at 09:31

Originally posted by cartoonkitty
I need to do experiments with NO2, can anybody recommend an appropriate gas mask.

Lets assume you do whatever it is you do with nitic oxide that really calls
for using a glove box, and your skin and immediate surroundings can
take the punishment, have you completely considered what may happen to
some passerby who is unaware of your activities ?

Really any military issue gas mask will serve your purpose. however those
that are available from retail Army Navy stores are good if you only wear
them at halloween. The U.S M-9 chemical mask was the mainstay for years
and still available in serviceable condition. It labors your breathing somewhat
and you need to really suck to get a breath. The important thing is to check
that the filter that you use is rated for NO2. The standard army mask has
been the M-17 for many years, with two filters this breaths better.
Be aware that military masks have goggles which limit your field of vision.
Hazmat masks are fancier and have visors but are also more expensive.
Masks come in sizes, one size does N O T fit all, it has to fit you.
There is a proceedure to adjust it so that it is hermetically seated
to your face. Beards and facial hair defeat it's function.
Most of all know that the filters have a definite useful time limit. If you value
your lungs don't exceed recommendations for replacement.



a) Loosen the head harness straps until the cinch is approximately one ( 1 )
inch from the buckles.

b) Holding the mask firmly against the face, center the head harness pad
on the back of the head and hold it in place with the other hand.

c) Remove the hand from in front of the mask and adjust the forehead straps
by grasping the clinch and using short quick jerks.

d) Adjust the cheek straps in the same manner.

e) Remove the hand from the head pad and adjust the temple straps
in the same manner.

f) ( M-9 only ) Fasten and adjust the neck strap.

g) To check mask, close off the inlet valve / valves and attempt to inhale,
holdingyour breath for several seconds. The mask should collapse against
your face and no air should enter the mask, as long as you hold your breath.

h) The mask may be removed by grasping the lower exterior and pulling it
away from the face up and off.

i) Store the mask with the adjustments you have made.


1) The very first step is to take a breath and stop breathing.

2) Grasp the facepiece with both hands, sliding the thumbs up inside so that
the facepiece is opened to the fullest extent.

3) Place the chin in chin pocket, then pull the head harness over the head
making sure that all head straps are straight and the head pad is centered.

4) Smooth the edges of the facepiece on the face with an upward and
backward motion, pressing out all bulges to get an airtight seal.

5 ) If the air you are in is contaminated you must clear the air from inside
the mask. To clear any air from the mask, cup the heel of your hand over
the outlet valve and blow hard. ( The M17 will require the other hand also
to cover the voicemitter.)

6) Check for leaks by placing the palms of your hands over the inlet valve caps,
breathing in lightly, and holding your breath. If there are no leaks the mask
should suck in toward your face and stay that way until you breath out.
( holding your breath for ten seconds is recommended )

7) you are now protected and ready to work. If you need to leave to a safe area
for rest and remove the mask, you must repeat the above proceedure
to put it on again every time.

You need to have the manual for the mask that outlines everything else you need
to know about care and maintenance.


[Edited on 7-8-2006 by franklyn]

Dangerous proceedures

chloric1 - 6-8-2006 at 11:05

Some prudence in handling dangerous fumes is needed here. If you desire to handle Nitrogen dioxide, chlorine,bromine, hydrogen cyanide/sulfide etc. you need to plan around your neighbors. I have not yet experiemented with these lethal vapors yet as I do not have the safety gear as of yet. My plan was when I aquire the mask or fumehood, I will perform these experiments in the wee hours of the night to minimize unexpected encounters. This would also minimize suspicious eyes from prying.

Magpie - 6-8-2006 at 14:04

chloric1 I agree that one must always be aware of the sensibilities of his neighbors. My fume hood pulls around 500 cfm so I'm usually not too worried about offending their olfactory sensibilities. However, I occaisionally do check this by walking around the house just to "test the airs."

When my wife comes in the front door after work I often ask her "has the chemist been here?" She usually says "no," which is an indication that she cannot detect any air pollution and that I have therefore been successful. :D
However, one chemical that everyone seems to detect right away, whether or not I have used the hood, is diethyl ether. :o

The fume hood is a bit noisy, however. So I try not to run it when the neighbors are near that side of the house.

Luftwaffe - 13-10-2011 at 21:10

I intend on synthesizing WFNA with my vacuum distillation setup but I am concerned about safety so I've been looking into respirators. So I need a respirator that can handle both NO2 and Nitric Acid and have yet to find a cartridge that protects against either of those. Yet despite the lack of hardware store acid cartridges that state protection against nitric acid and NO2, I see many people saying they use them for doing nitrations and what not.

Is it fine to use an acid cartridge for working with nitric acid/nitrogen dioxide? If not what cartridge should be used?

Bot0nist - 13-10-2011 at 22:23

Honestly you will be much better off by moving the harmful gasses away from you either by working under a good fume hood, using an inline duct fan to suck the NOx away, or use cross ventilation outside and stand upwind from the distillation. The need for a mask implies that you intend to preform this distillation in a place were the gasses could accumulate. This is a bad idea because oxides if nitrogen are acutely toxic, damaging to surroundings, and very persistent about lingering in a room. I assume you'll be using a vacuum to get WFNA. If your vacuum pump isolated from the off-gas then it could remove most of the problem. Still use good ventilation incase things don't go as planned.

IF you get crafty with some tubing a wash bottle train can trap the evolved gasses and efficiently solve you problems before they reach the vacuum pump.

[Edited on 14-10-2011 by Bot0nist]

Luftwaffe - 13-10-2011 at 23:42

I intend on doing the distillation right at my garage door, while it's opened so there would be very little wind of which would be turbulent and non constant. My issues I don't believe would be the accumulation of the gases but rather the acute whiff or two especially when dismantling the apparatus. I use a water aspirator that I could run 10ish meters away from the distillation but the problem of dismantling is still there. Even opening the damn bottle of WFNA would be dangerous without some protection let alone pouring and using it.

So my primary problem isnt NO2 since the formation is low at the temps I am working at but rather the nitric vapor that is inevitable when I even open the stuff.

Now I suppose would be a good time to discuss the effectiveness of acid cartridges. Nitric acid is a strong acid but also a strong oxidant which is maybe why the cartridges are not rated for such gases. Would the cartridge work but with a lesser lifetime or not work altogether? It would seem that whatever chemical neutralizing agent in the cartridge would certainly react with the acid but in a way that is damaging to it. Remember I am only exposed to the gases intermittently when I have to pour or clean up so perhaps an acid cartridge would be enough?

Finally I will try to conclude with the options I have:

1. Setting up a 2ftx2ft fan blowing air outside of the garage beside my reaction vessel or distill
2. Using an acid gas respirator

Ultimately I will be using both but for curiosity sake would only one of those options work so I may know the effectiveness of each individually. Or is the synthesis all around too dangerous to do in said environment and I am screwed in all regards and REQUIRE a fume hood?

Steve_hi - 14-10-2011 at 06:56

I made wfna outside and the wind kept changing direction I think the best is a fume hood it would also be better for dismantling as well.

Bot0nist - 14-10-2011 at 09:53

I use two large fans outside to direct the flow on still days. One on medium blowing over the bench, one on high at the end of the bench blowing away.

A long piece of 8 inch duct with a cheap 8 inch inline duct-fan in one end can be hung to a wire and positioned over the mouth of a flask or beaker to suck fumes away from a reaction and lead them to a safe place. I use this with some outdoor nitrations. It works good, but the gasses kill the fan after a while. This is not recommended for flammable vapors, as the fan may cause a flash fire.

[Edited on 14-10-2011 by Bot0nist]