Positive air flow respirators?

Anybody using positive air flow respiration or remember any threads about it? All the dust and vapors are getting to me, must try something besides particle masks and regular respirators. Thanks

have you tried a full face “regular” respirator like a 3M 6800?  If dust and fumes are getting to you, your respirator either doesn’t fit (note they come in different sizes), or you’re using it wrong – should not be experiencing fumes or dust at all… 

In addition to size, according to HAZWOPR/OSHA standards more than 3 days(I think) facial hair growth interrupt the seal. the chemical plant where I work  wants you clean shaven.  And the respirator you bought before you were married and 20lbs lighter may not fit you today

 Also remember a Large for one manufacturer and even models by the same manufacturer  does not equal a Large in a different manufactuere or model.  

Quick ways to check the fit are to put palm of hands over cartridges and inhale,  It should collapse and you shouldn't feel any air pulling in from around the seal.   Then on the exhaust valve, my north half face has it under the chin, place the palm of your hand an blow out.   It should puff up with positive pressure.   If it fails either of these try adjusting the straps and that doesn't work  you'll probably need a different size.   At work we have a computer run tester that monitors the air outside the respirator vs. inside while you talk and do different activities but those are some quick checks.

Also remember to keep your cartridges / respirator in a dry place...ziploc bag.   Moisture can diminish the effectiveness.   And change them at least every couple of months even if you don't use them.   I use a hepa for sanding/shaping/ wood working(black walnut is a suspect carcinogen) and then a hepa/charcoal combo for glassing. 

As far as positive pressure i don't know too much other than becareful with your compressor.  If it gives off an odor or is near a car exhaust or  fireplace...not good.   Remember you shouldn't be able to taste year.

Hope that helps


they are expensive

probably a grand or more for the whole setup

and the batteries don't last too long

i have a cheap (rockler) one for woodworking but i wouldn't use it for boards.



wayne lynch uses one

i once saw a cheap bumble bee positive air suit that used hooded tyveks on ebay

there was a ice chest cooling attachment to cool the air filling the suit all for around $600

way cheaper than a normal hazmat  for asbetos removal..

i searched under "asbestos abatement"

once you become sensitized to epoxy there's no other way to work with the stuff other than with a self contained level 2 hazmat on.


found it.. here you go..




Trend Airshield-Pro
Airshield Pro
Airshield Pro
Item#: airpro

Product Description
Trend Routing Technology has taken their successful face shield and made numerous changes to create a new shield both easier to use and nicer to live with. Relocating the motor toward the rear of the helmet has created better balance and reduced noise and vibration at the headband/forehead area of the shield. Unit also features attachment points for optional ear protectors & audible low battery warning.

Twin filters increase filtration area by 400% providing better protection against dust. A replaceable visor is positioned close to the eyes, improving the field of vision. Optional tear-off visor covers can be purchased to keep the visor clear and clean. A moisture-wicking headband assures comfort during extended use. The eight-hour Ni-MH battery pack in the new visor can be quickly changed-out with a fresh battery pack or charged in place in under 14 hours. This unit will come with a battery charger.

Thank you swaylock crew, Very helpful, I'm on the hunt for a solution. John C. San Diego

Try to find an old cpap machine used for sleep apnoea, what’s the bet there are thousands lieing in the back of suppliers, hospitals etc especially in the USA, they are only legally accesible via prescription in the USA, so sourcing one may be a problem, but worth the effort.  Because of our NZ free health system, used ones here have no value, We get new ones when we need them for nothing, the old ones are worthless, go President Obama. I would imagine that you could pick up a ten year old machine for $50, buy a  brand new full face mask, probably $150, and plastic hose, $40 should give you enough hose. Place the pump/machine outside your shop, garage away from the fumes, set your airpipe, hang it from the ceiling, place pump/machine outside the workshop, connect up and you are away. The new masks that go over nose and mouth are the ones to get and have a rotating inlet so you can string the airhose from the ceiling and set the intake at any angle that you feel comfortable with, vision wise.

The secret is the nose and mouth mask and the non-collapsing airhose. If you can’t find a cheap cpap machine,  a computer cooling fan built into some sort of inlet outlet system might work. For a gang who have worked out how to vacuum bag, building a simple airpump and getting pressures right shouldn’t be too diffficult. No need for filters if you are accessing air away from the workshop. Looking forward to the picures.