Dust Mask's

[Steve N]

With my 3M 7800 those are industrial rated masks, and some users are literally in them 8 hours a day. I've never gone that long, but for an hour or two I don't fog, they are vented very well from within. Now where the seal contacts your face it can get kinda sweaty in the heat of Summer, but it sounds like you get sweaty without a respirator, so I'm not sure if that is different. I can't say I feel like there is dripping moisture though, and never back into my eyes like happens when I am outside doing yard work without a bandanna to catch the runoff. At our site some of the welders wear a bandanna around their head right above their eyes. I've never given it a thought. I'll have to ask if it is for sweat. We have another respirator on site, it's the Scott AV3000, our ERT crew wear these when they go SCBA, with a supplied air tank. Without the supplied air, those are sweat pigs, with the air it's comfy, and cool. Some of the Firefighters here may use them, and could probably validate that. Those masks could be used filtered just like the 3M 7800.

Other thoughts I didn't think of before.

No mask will fit well over a beard, facial hair in the seal of the mask is a no no if you want it to be effective.

N-95 is 95% efficient at 3 microns

N-100 is 99.7% efficient at 3 microns

there is no doubling or tripling effect in those numbers, so the difference is 4.7% and a machine can tell this difference, humans usually do not. Either can be sub 70% in the presence of facial hair, or a sloppy, poor fit. To actually know what your numbers will be you would need to be fit tested. $$$$$$$$$ if you can find a Doc to do it. I recommend the n-95, as the lower cost make them more affordable to most, and if you can afford it, chances are you will use it.

[fixtureman]

I've had good luck with RZ masks

[MichaelMouse]

Effectiveness is not a function of filtration, but deflection.  Dust smaller than the advertised filtration capability will not penetrate the mask if it hits a fiber, which it will if the mask is properly worn.  The negative pressure of inhalation is not enough to draw the particle through the maze of crossing fibers.  Accidental contact with the fiber of the mask is all that counts beyond facial fit, which is also a problem in that it decreases the pressure within a well-sealed mask so that fine material, given plenty of time, might find its way through the maze of felted paper. 

For your consideration, , the volatiles - gases (odors) - emitted while processing the wood represent a greater pulmonary danger than inhaled organic material produced by sanding maybe an hour a day.

[Steve N]

Effectiveness is not a function of filtration, but deflection.  Dust smaller than the advertised filtration capability will not penetrate the mask if it hits a fiber, which it will if the mask is properly worn.  The negative pressure of inhalation is not enough to draw the particle through the maze of crossing fibers.  Accidental contact with the fiber of the mask is all that counts beyond facial fit, which is also a problem in that it decreases the pressure within a well-sealed mask so that fine material, given plenty of time, might find its way through the maze of felted paper. 

For your consideration, , the volatiles - gases (odors) - emitted while processing the wood represent a greater pulmonary danger than inhaled organic material produced by sanding maybe an hour a day.

Do you just have a burning need to discredit anything I say? I would love to see the source for where you got this disinformation from.

Negative pressure?? Deflection????

[MichaelMouse]

No, you just say so many absurd things that it's necessary to correct them before other folks start believing you.

Though one wonders how you achieved adulthood without figuring out that a particle that floats in air won't penetrate past the first obstacle it meets without help.

[Window Guy]

Thank you for the response's everyone I appreciate this very much. Yes the paper ones I picked up at HD was a single strap, and I want some light, comfortable in the $25 - $50 range if possible. I have seen the ones that look like a back pack, not only are they expensive ( I know trust me you can't put a price tag on health ) but I am sure they are heavier and hot.


Steve

[MichaelMouse]

I think wearing a single strap is better than having something fancy but uncomfortable hanging on the wall.  The barrier up front, where the lower pressure during inspiration is greatest, is going to do for pretty much anything which you don't pick up with a dust collector.

[Terry W]

Is anyone using the washable dust masks? I read about them in Jim Tolpin's Woodworking book. They are only $15-ish. If you read the fine print they filter down to 1 micron, are washable / reusable up to 100 times and have an antibacterial coating.

[MichaelMouse]

Getting pretty tight down there at 1 micron.  Our original HEPA masks were so tight it was impossible for some of the folks to wear them without bulging their eyes.  Smokers found it especially difficult to inhale.  Not used much any more, since simpler barrier masks are better tolerated and near as effective with proper fit.  Where the HEPA type comes into play is when it really NEEDS to be a filter, which is to say, where higher pressures/vacuum might draw particles through it after some time.   The N95 is most common in EMS now, though N100 types are still out there.