How long does dangerous dust remain in the air

[photobug]

I have yet to build my dust collection it is next on the list.  I do have a Jet AFS 1000B ambient air filter.  I just upgraded from a disposable cloth mask to a 3M to where when cutting on a power tool.  It is pretty comfortable so I keep it on for 10 minutes or so after cutting.

I don't run the Jet air filter often.  I am just looking for advice on how I should approach my dust mask and filtration usage to keep me as safe as possible without wearing the dust mask longer than needed.

[Wild Turkey]

The more you run the air filter the cleaner the air will be and the healthier your lungs will be.

"How long" is a function of how clean your filter is, how much air the blower moves and how well it is positioned.

Filtering air is definitely a case where "more is just enough"

[K. L. McReynolds]

There are different kinds of airborne particles.

Small chips, heavy dust, fine dust and superfine dust.

Examples:
Small airborne chips come from saws and planers.
Heavy dust comes from sanding with 40-80 grit sandpaper.
Fine dust comes from scraping and sanding with 150-up grit sandpaper.
Superfine dust comes from sanding really soft woods with a really fast hi grit sander or sanding finishes with hi grit sandpaper.

I sanded our unfinished hard maple floors with a USand machine. Basically a 4 position ROS using 8" discs and really good dust collection.. Started out with the windows open, fans blowing out and a respirator. Using 60 grit paper. After 10 minutes, I took off the respirator and shut off the fans. The only detris outside the collection bag was granules(actually tiny balls) of wood. Went like that clear up to 150 grit.

I brought out my PC ROS and had to use the respirator.

In my shop, I have a 2hp Griz DC. Hooked to a contractor TS(for chip collection since very little dust is collected), a Delta planer(13"0, a home made router table(collection is minimal since I really did not design it for that when built since my shop then was outside), a Griz jointer, and a Rigid OSS. The last two machines are the closest to the DC, jointer does fine, OSS does middling well at getting the heavy dust.

Only time I use the respirator is during long sessions with the OSS and ROS. The dust from the other machines is too heavy to be airborne long.

[Phil Thien]

Dust (even the fine stuff) settles much faster than we had been led to believe.

However, it stirs-up pretty easily, too.

An air cleaner is a pretty good idea.

[photobug]

Dust (even the fine stuff) settles much faster than we had been led to believe.

However, it stirs-up pretty easily, too.

An air cleaner is a pretty good idea.

Kind of what i thought.  I read an article on another forum where someone had the same air filter and plugged it in first night and left the timer on when he was done.  It almost melt burned down his house.  I wondered why someone would leave the filter on timer and go away for hours.

The main problem I have in the past was cheap mask was fogging my safety glass,  I felt I had to choose my eyes or lungs to protect.

My current problem with the new 3M mask is, my glasses no longer fog but do not fit on my face very well, the respirato makes my glasses have to ride up higher and I can't use the reading glasses bifocals I just got, it sucks getting old.

[daddo]

Kind of what i thought.  I read an article on another forum where someone had the same air filter and plugged it in first night and left the timer on when he was done.  It almost melt burned down his house.  I wondered why someone would leave the filter on timer and go away for hours.

The main problem I have in the past was cheap mask was fogging my safety glass,  I felt I had to choose my eyes or lungs to protect.

My current problem with the new 3M mask is, my glasses no longer fog but do not fit on my face very well, the respirato makes my glasses have to ride up higher and I can't use the reading glasses bifocals I just got, it sucks getting old.

 Buy a second pair of glasses or find some old ones and remove the nose supports. See if that works for ya.

[MichaelMouse]

Dust (even the fine stuff) settles much faster than we had been led to believe.

However, it stirs-up pretty easily, too.

An air cleaner is a pretty good idea.

Turbulence from the dust collector keeps it airborne longer than quiet air.  May keep things where dust might settle cleaner, but your nose isn't one of those places.  If the dust bothers, defend the nose.

FWIW, the most "dangerous dust" is not the cellulose itself, but the extractives it may contain.  Long exposures to atmospheres opaque with cellulose dust can lead to lung problems, but defense at the source with a vacuum, and at point of entry - your nose - easily defend against it. https://www.healthline.com/health/byssinosis

[TomFromStLouis]

If I have a window open and the the overhead air filter on high I take my mask off maybe five minutes or so after using the table saw. On machines where dust collection is more efficient I may not use the mask at all.

[daddo]

Sanding creates the most problematic dust for me. I'm setting up a sanding station outside under the shops porch. Even with the DC, I can spend 20 minutes sanding and later 2 hrs cleaning up.

[wrb]

I would run the air filter continuously while you are in the shop and then have it shut off two hours after you leave. I used a Dylos particle counter to verify the effectiveness of the air filter and it is actually very effective. Of course, it is only part of the solution. You definitely should collect dust at the source first.