This article is from the Woodworking FAQ Collection 2, by multiple authors.
From: email@example.com (Barry D. Smith)
Date: 25 Jan 91 13:13:19 GMT
There was a letter to the editor in American Woodworker a
couple of months ago that addressed the use of the fan/furnace filter
method of removing dust from the air. The person claimed that furnace
filters only effectively remove dust particles down to 50 microns,
while the nasal passages remove dust to about 20 microns (I may have
these numbers wrong). In any event, he claimed that only dust
particles less than 10 microns are considered dangerous. The moral
seems to be, if you want to remove dust from the air for health
reasons, you need a fairly sophisticated system.
On the other hand, if you can capture the dust before it gets
into the air, you don't have any problem. The problem here is that
all dust collection systems I have seen, ranging from bags on the side
of belt sanders to vacuum-based systems, must have a means of allowing
the air flow to move freely (without an exhaust, a vacuum cleaner is
useless). This air flow carries a lot of dust away from the system
and into the air. In order to collect dust in a bag (like in a
sander), the bag material must allow air to flow through it (this
means the dust collection system gets worse as the bag fills).
The bottom line seems to be that there is no inexpensive way
to remove enough dust from the workplace to remove any health hazard.
I'm not saying you shouldn't use a mask and dust collection system.
Just keep in mind that short of spending thousands on a permanent
system that routes all dust from each machine to outside the shop, the
best you can do is make the shop air a little safer and a little more