Any Phoenix area creekers willing help me with an air particulate study

[Earl Kelly]

Bill,

Very good. Can you elaborate on the Particles and the relationship to mg/mg3. Also the descrepancy between Outside air with the Note1 which indicates inside shop air. I'm sure that's just a mixup.

The MDF cutting, I would think, would rate somewhere near the top as for release of dust when sawing. I would think routing or sanding, MDF would be worse.

Again very good test setup and I think with just a little explanation of the relationships, anyone could understand the results. It will be interesting to compare with other shop setups. Might be good to note the estimated hours per week the shop is used or commercial/hobby.

[J. Scott Chambers]

Bill,

Where is the data from the Test Pre-Cut, Note #3 on your friends shop?

[Bill Pentz]

Bill,

Where is the data from the Test Pre-Cut, Note #3 on your friends shop?

That test was not done because it is looking to see if there is a problem with the filters storing and putting back fine dust into the shop air. With his DC system both outside and with no filters, that test was not needed.

bill

[Bill Pentz]

Bill,

Very good. Can you elaborate on the Particles and the relationship to mg/mg3. Also the discrepancy between Outside air with the Note1 which indicates inside shop air. I'm sure that's just a mix up.

The MDF cutting, I would think, would rate somewhere near the top as for release of dust when sawing. I would think routing or sanding, MDF would be worse.

Again very good test setup and I think with just a little explanation of the relationships, anyone could understand the results. It will be interesting to compare with other shop setups. Might be good to note the estimated hours per week the shop is used or commercial/hobby.

Earl,

The issue with note 1 and outside air was a mental lapse on my part. I’ve already fixed the original. Sorry.

The relationship between particle counters and mass readers is not so easy and something you would have to get into the physics of testing to understand better. I really did not want to have to cough up the money for both a mass gauge and a particle counter, so did quite a bit of research.

What I found out is most of today's better particle counters use a laser system to do counting. These counts can be fairly reliably converted via formulas over to a mass reading meaning milligrams per cubic foot or cubic meter. Many testers do not want to use these fairly complex conversion formulas and would much rather directly show their customer a number they can understand with no translation. Those worried about OSHA or ICGIH compliance want to see milligrams per cubic meter (mg/m^3) mass readings, and those interested in medical air quality want both a mass reading and a particle count by particle size range.

The Met One AeroCet that Don Baer recommended and I bought to add more real measurement for hobbyist exposures is unusual and costly. It directly gives both a particle count and a mass reading. Early mass readings were done with weighed filters requiring an extended time frame, typically eight hours to ensure getting ample mass that the available weighing equipment could provide an accurate measure. This gauge does this same testing in two minutes, but that does not comply with the industry standards that require a long term measurement with tracking to ensure no fifteen minute period exceeds permitted maximums. I struggled for quite a while and finally decided that no matter how much I might prefer the longer term testing, my desire to instead set some accurate baselines would be far better served by being able to do lots of testing. In short, I went with the gauge Don recommended, plus bought a separate mass gauge. The latter is proving far less useful and accurate.

bill

[J. Scott Chambers]

That test was not done because it is looking to see if there is a problem with the filters storing and putting back fine dust into the shop air. With his DC system both outside and with no filters, that test was not needed.

bill

I would think that if the ambient air is dirtier than the air in his shop with no woodworking, and you turn on a "large" dust collector that exhausts to the outside, with no filters, that the makeup air is coming from the outside. If that outside air is dirtier than the inside, it would make sense that the dirtier makeup air would contribute to polluting the inside air, raising it's particle count?

Unless he has a well filtered make-up system. Perhaps I'm not understanding what you were trying to prove. I am curious how much the particle count would have been raised by just running the DC, and bringing in that makeup air.

[Bill Pentz]

J. Scott,

Since that test was to see if he had a problem with his filter bags passing the fine dust right through and he had no filters, it was not run. The last test did show that by replacing the air inside his shop that was contaminated with wood dust with outside air that we got levels that moved toward what we got when testing the outside air.

bill

[Art Mann]

I would like to Applaud Bill Pentz and Don Baer for your efforts. Such surveys will provide much interesting and useful information. I do think it is important, though, to point out what such an effort will and will not accomplish. What you are doing is not a scientific experiment but rather an uncontrolled survey. By surveying enough hobby shops, I think it will be possible to get a kind of ballpark figure for wood dust particle counts in shops with "good" and "bad" collection systems. I put those terms in quotes because they are not well defined. Even so, that will be very informative and useful information. This information will not allow you to predict the performance in a particular shop of a particular dust collection system with any level of accuracy because there are far too many uncontrolled variables. About the most you can hope for would be the development a set of "rule of thumb" type guidelines. Again, this information would be quite valuable. You will not be able to establish the effectiveness of one type or brand of dust collection system as compared to another because, once again, there are far too many uncontrolled variables from one installation to another.

If you really want to do a quantitative analysis or compare equipment types and brands in a "real world environment" as you call it, you are going to have to assemble a test shop with a given woodworking equipment set, a tightly controlled environmet, standard materials, and a highly repeatable test procedure. (Incidentally, I don't think MDF is a very typical or appropriate test material.) This may be more than you bargained for, but nothing less will yield any real quantitative results.

As valuable as your work is, it does not address the bigger question of what exposure level of what type of dust in what concentration is likely to produce health problems. Unfortunately, the answer to that question defines the relevance of your measurements. Let's take cigarette smoking as an analogy. Hardly anyone will deny that cigarette smoking causes lung cancer. Nobody in their right mind will assert that smoking one cigarette will cause lung cancer. Enough research has been done on cigarette smoking to actually predict the percentage of deaths due to a given level of consumption. I know of no such research that has been done in hobby workshops. The surveys of workers in wood product industries I have seen have been contradictory and inconclusive and are not really relevant to the hobbiest woodworker anyway. I suppose you could say it would be better to be safe than sorry -- but that would mean we would all have to stop woodworking.

[Bill Pentz]

I would like to Applaud Bill Pentz and Don Baer for your efforts. Such surveys will provide much interesting and useful information. I do think it is important, though, to point out what such an effort will and will not accomplish. What you are doing is not a scientific experiment but rather an uncontrolled survey. By surveying enough hobby shops, I think it will be possible to get a kind of ballpark figure for wood dust particle counts in shops with "good" and "bad" collection systems. I put those terms in quotes because they are not well defined. Even so, that will be very informative and useful information. This information will not allow you to predict the performance in a particular shop of a particular dust collection system with any level of accuracy because there are far too many uncontrolled variables. About the most you can hope for would be the development a set of "rule of thumb" type guidelines. Again, this information would be quite valuable. You will not be able to establish the effectiveness of one type or brand of dust collection system as compared to another because, once again, there are far too many uncontrolled variables from one installation to another.

If you really want to do a quantitative analysis or compare equipment types and brands in a "real world environment" as you call it, you are going to have to assemble a test shop with a given woodworking equipment set, a tightly controlled environmet, standard materials, and a highly repeatable test procedure. (Incidentally, I don't think MDF is a very typical or appropriate test material.) This may be more than you bargained for, but nothing less will yield any real quantitative results.

As valuable as your work is, it does not address the bigger question of what exposure level of what type of dust in what concentration is likely to produce health problems. Unfortunately, the answer to that question defines the relevance of your measurements. Let's take cigarette smoking as an analogy. Hardly anyone will deny that cigarette smoking causes lung cancer. Nobody in their right mind will assert that smoking one cigarette will cause lung cancer. Enough research has been done on cigarette smoking to actually predict the percentage of deaths due to a given level of consumption. I know of no such research that has been done in hobby workshops. The surveys of workers in wood product industries I have seen have been contradictory and inconclusive and are not really relevant to the hobbiest woodworker anyway. I suppose you could say it would be better to be safe than sorry -- but that would mean we would all have to stop woodworking.

Art,

I fully agree with you with respect to equipment testing, but the goal here is to determine if hobbyist shops have a serious problem with a build up of fugitive dust. By problem dust I mean particles smaller than about 10-microns. By fugitive dust I mean dust that either is missed during collection or that passes right through our filters. In 1999 when I started my dust collection research OSHA testing of small shops that apply for commercial license and get government air quality testing almost all fail the airborne particle tests if they exhaust their cyclones or dust collectors inside into bag filters. Because fine dust takes six months or more to dissipate, the certified inspector who tested my very clean looking shop said hobbyist shops will have a similar problem. It was his contention that it is not so much how much woodworking we do, but instead the build up of this residual dust that poses the most short and long term threat to our health. The purpose of the testing that Don and I are trying to organize is to assess if there is a real problem with this accumulation of fine dust in our shops.

I agree with you in terms of what it takes to evaluate the various small shop dust collection equipment options. Back in 2000 through 2002 I did exactly as you suggested and setup a lab at the university to do airflow and filter testing. I did this testing as a private individual who was very upset because the system I trusted to protect my health pushed the particle counts in my shop to dangerously unhealthy landing me in the hospital.

1. For the dust collectors I tested every major brand of dust collector sized 1.5 to 2 hp and did that testing using standard Dwyer and ACME testing protocols without filters and a simple test pipe. I posted on my web pages just like the various magazine tests the actual fan curves. I did that testing because I found some pretty ugly funny business with the vendor ads and some of the magazine tests. My testing showed Jet, Delta, Shop Smith and Felder advertised maximum airflows that could be duplicated in the testing, but all others exaggerated their airflows in some cases by well over 100%. Worse, other than these same brands, all of the maximum airflows resulted in the motors pulling far more than their rated amperage. In fact, both of the major magazine tests at that time burned up motors on test units.
2. For the cyclones only Delta and Powermatic provided the airflow they advertised. All other airflows were badly exaggerated and also resulted in the motors working at far over rated amperage at maximum airflow conditions.
3. The filter situation was dismal. I used certified test dust weighing new filters and collection bags before and after running that dust through. I tested new filter bags following the ASHRAE testing procedures for testing filters for indoor use. I posted those test results as well and they were pretty ugly as the typical filter passed 20 to 30 times larger dust particles than advertised. The vendor community complained loudly saying that dust collection has always tested with what are known as fully seasoned bags, meaning the bags have built up a thick internal cake of fine dust in the filter strands that does not come out with normal cleaning. I retested running the test dust through over and over until achieving the level of filtering claimed by each vendor. At that level of dust caking, most barely passed any air and all but killed the airflow needed for minimal dust collection.

What most upset me from my own testing is it was painfully obvious that the magazine testers were either gravely incompetent, or were not testing the same machines as I tested. Not thinking anyone was incompetent I contacted two of the magazine testing crews and started comparing notes. What we discovered is some of the vendors had slipped in ringers for the magazine tests using bigger motors, impellers, and blower housings than what they actually sell as these same models. After I published my test results, one vendor was so upset they immediately threatened to sue me. After talking with my attorney and seeing hobbyists all over the country duplicate my airflow testing, they instead decided to say it was all an oversight and they came out with a new model after the test that used the bigger blower motor, impeller, and blower housing actually run through the magazine testing.

Unfortunately, in early 2003 another round of respiratory problems put me into congestive heart failure and pulled the plug on my continued testing. I left my test results and fan curves posted with the detailed test data on my web pages. Meanwhile, based on my testing the dust collection and cyclone vendors began rapidly improving their equipment and started advertising real airflow numbers simply because so many hobbyists were following my lead and buying a set of test gauges to verify how well their equipment actually worked. By late 2004 a few of the vendors and my advisors who looked over my web pages for accuracy, convinced me that my test data was getting dated and I needed to either update or pull down those prior test results because they were just no longer applicable. My attorney who sadly was kept far too busy by helping me avoid the numerous threatened lawsuits agreed and I pulled down my test data.

Although my health is better and I am doing some testing again, I am still on pretty limited duty and frankly have zero interest in warring with the vendors that continue to push and take every advantage. Lacking the time, energy or resources to resume a full scale lab testing program, I have tried hard to share with the various magazine test groups to improve the quality of their testing. This interaction has helped some, but still needs some work. I really want the magazines to use a high quality digital amp meter and cut off any fan curve as soon as the motor’s rated amperage is exceeded. Likewise, I would like someone to cover the costs to run the hobbyist bag and cartridge filters through a filter testing lab and label each with an ASHRAE certification that says what sized particles 99.9% of the time will be filtered by each unit. Based on my prior testing most are going to get a certification of 5 to 10 times worse than claimed in the ads.

This is important to me because most claim 1 to 2-micron filtering and we know that it is the under 10-micron material we know is most unhealthy. The under 5-micron stuff tends to lodge in our airways and the under 2.5-micron stuff lodges deep in our lungs. The 1-micron and smaller can actually pass directly from our lungs into our blood stream.

Anyhow, thank you for your thoughts and pointing out these concerns. I agree that these tests are not going to tell us more than what situations tend to build up high airborne dust levels, but that is what we want to know, how big the risks are for hobbyists.

bill

[Alan Simpson]

Bill, I would love to see the full results of your test that you referenced. Quite frankly, I'm surprised not to see them on your site.

[Scott Hochuli]

Don,
If you're still looking for Phoenicians to participate in the air particulate study, you are more than welcome to come by my place. It could also turn out to be a nice before and after study, as I am currently running a delta 50-850 dust collector, and am hoping to have a cyclone on order by the end of the week.

[Doug Arndt]

Bumping an Oct 2006 thread .... I was wondering if any results are available ?

[Ken Fitzgerald]

Doug.....I don't know the particulars but Don is no longer a member here. I don't expect him to update this thread.