Best Dust/Gas mask

June 16, 2005 1:51 PM

I get a bit concerned about my lungs when I paint, saw, sand, blow dust around, or use nasty chemical solvents. Anyone have any gas and/or dust mask recommendations?
posted by sdis to health (9 comments total)

I have asthma and tons of allergies, and the generic gray rubber mask (the one with two filters, one on each side and one in the middle) from Home Depot/Lowes worked great for me. We've done extensive house renovations, so at times we've had sawdust, sheetrock dust, paint and nasty chemicals all in the air. Sometimes at the same time.

The most important thing is to make sure the mask fits your face properly. Once you put the mask on (using both the over-the-head and around-your-neck straps), cover the middle filter (the one directly in front of your mouth) and try to blow in and out. One of those directions should be impossible/hard to do (I can't remember which direction and the mask isn't here with me). Next cover the two side filters and blow in the other direction and that way should be difficult. There should also be no air leaking out from arounf the gray rubber part.

That test makes a lot more sense when I'm doing it than explaining it...
posted by Moondoggie at 2:09 PM on June 16, 2005

Oh, one more thing - if you know what sort of solvents you'll be using, check to make sure the mask and its filters cover it. I seem to remember that the basic filters don't protect you from certain kinds of chemicals, but the package will tell you more.
posted by Moondoggie at 2:11 PM on June 16, 2005

I always use AO Safety masks (you can choose the best one for your projects from the website) and have never been disappointed.

Moondoggie already nailed the best testing method.
posted by jeanmari at 2:23 PM on June 16, 2005

Yes, just get a respirator with two filter cartridges instead of a dust mask. They're only about $20-30. A respirator with one filter cartridge labours your breathing a little, so two is better, and the filters are much better than a dust mask. Also, the seal onto your face is much better with a respirator, which is important, as any gaps kind of defeat the purpose of wearing a mask.

There are different filters for different tasks (eg some are designs to stop micro particles, while others are designed to stop vapours), and you can purchase these seperately, but generally the pair of filter catridges that come with the respirator are good general purpose ones. Read the back of the package for a list of things the do and don't work for. If it's a big enough store, they might have a range of sets, so just read the labels - they'll tell you what's what.

You need to replace cartidges periodically, but unless you're using them all the time, this could be years - basically you replace them when they're clogged up so that breathing is more difficult. (Some filter types need replacing sooner, but that's typically for just one layer of the filter, so failing to replace it might mean it still works fine against dust, but is less effective than it's meant to be against vapour).
posted by -harlequin- at 2:24 PM on June 16, 2005

Moondoggie is right on. Most of the regular dust masks are ok, if you wear them correctly (which most people don't), but the respirator works best.
posted by recurve at 2:49 PM on June 16, 2005

Absolutely don't use a paper mask. Use a good half-mask, as other suggest, and make sure that it seals properly to your face. If you have any facial hair (sorry if I've got your gender wrong), it may cause problems, as may strong cheekbones or scars. You can do a rough check of fit by removing the cartridges and covering both holes with the palms of your hands. If you can't breathe in, then you're probably ok. Now, check to make sure that the valve under the chin is working by blowing out with the cartridge ports covered.

The two best manufacturers of masks are Scott and MSA. Scott is what most firefighters use; MSA is the choice of many Hazmat first-responders. Scott is American, MSA is german, if that makes a difference to you.

Next make sure that you've got the right cartridge. For paint thinners or solvents, you want one that covers VOCs (volatile organic compounds), usually marked with red/green or red/yellow stripes. For shop dust or wood dust, you want a HEPA-certified PM10 filter. DO NOT accept a non-certified filter. Don't bother with a smaller number (PM2.5, for example). Research isn't clear that they offer much more protection and they are MUCH harder to breathe through.

Cartridge replacement for the chemical cartridge is based on break-through time. This should be written on the package. Breakthrough times for VOCs through small cartridges is typically a few hours. If you ever smell solvent in your mask, change carts. When not in use, we store them in zip-loc bags. Large freezer bags will conveniently take the mask+cartridge combo.

The filters carts are easier---they just get harder to breathe through. Replace them as needed.
posted by bonehead at 2:53 PM on June 16, 2005

I always preferred 3M masks to AOsafety, but never tried Scott or MSA. 3Ms (and likely other pro brands) come in three sizes, and two rubber compounds.

VOC carts are useless if you don't keep it in a bag as noted by bonehead. As he said, VOC cartridges for some stuff, particle filters for others.. but you can get a set of each, and swap out the VOCs when you're doing wood sanding, so that you're not "spending" them on innapropriate tasks.
posted by Jack Karaoke at 4:08 PM on June 16, 2005

I'm going to go out on a limb and say that if you're doing a lot of this stuff you might want to get a dust collector.

I bought a cheapie from Harbor Freight and with some 4" sewer and drain pipe I was in business. I installed my piping in 1 weekend, tore it down and redid it better the next weekend. My shop is faaar more dust free since then.

I still wear a half mask like is discussed above.

The DC is best for dust, although it's great at removing larger chips and stuff too (I use a cheap ass cyclone seperator that is basically a garbage can with a special lid). I use it for finishing too. I have a big square thing that I made out of some dryer venting stuff that I position near where I'm finishing. Dust collectors move a lot of air, and they move it away from you (to where the DC is) so this can be a good way to clear fumes from where you're working. I do a lot of worth on a lathe so getting the fumes away from where I'm working is pretty important (#1 finishing ingredient I use is super glue -- noxious stuff. The dust gets very fine too as I sand up to ridiculous grits)

If you do a lot more work than I do you might want to step up to a true cyclone like an Oneida. That's probably not in your near future but thought I'd throw that out there.

This is probably not well known, but most woodworkers know how bad fine dust is for you. It's lung-cancer-causing stuff. Some species are poisonous also, and will give rashes or cause stinging in your lungs.

During the summer I often shave off my beard to get a better seal on a face mask, esp. since I sweat so much here in TX.
posted by RustyBrooks at 7:27 PM on June 16, 2005

For your general nuisance dust and a bit beyond you want a N95 for non-oil based environments. Beyond that, you need to ask the manufacturer or look online for th Material Safety Data Sheet (MSDS) of the chemical/product you are using and consult the appropriate Personal Protective Equipment (PPE) section therein.
posted by sled at 10:14 AM on June 17, 2005