Introduction

Innumerable people have asked over the years why continue to provide the research, time and money needed to keep up these Cyclone and Dust Collection Research web pages. The answer is simple. I don’t want to see other small shop users blindsided as I was.

We also need to know the odds of this happening to us to decide how much if any protections we want to provide. The damage caused by wood dust depends upon overall health, genetics, type of exposure, amount of exposure, frequency of exposure, and duration of exposure. Almost all medical studies that give the different probabilities of being harmed are studies of workers in large facilities that vent their fine dust away outside. These studies show about one in eight gets forced into an early wood dust related medical retirement. For those shops that vent outside and improve their dust collection ample to meet OSHA air quality standards the number forced into an early fine dust related medical retirement drops to one in fourteen. Government testing shows small shops that vent inside average two to five times higher dust levels by weight. Because we mostly use finer filters, the majority of this dust is made up of the fine invisible particles known to cause the most damage to our health. In fact, particle counts of the fine invisible dust for small shops that vent inside average thousands of times higher than shops that vent outside. As a result, even occasional small shop hobbyist woodworkers get more fine dust exposure in a few hours of woodworking that large shop professionals get in months. At these exposure rates all will get harmed.

Medical experts define fine dust as inhalable particles sized 10-microns and smaller which get by our natural protections and then get stuck in our tissues. We need magnification to see particles sized 10-microns and smaller, so these particles are invisible. A micron is one millionth of a meter. Human hair varies between about 40 to 100-microns thick. Government studies shows about 5% of the dust we make, which means one pound of every twenty is made up of fine invisible particles. Just two tiny thimblefuls of this fine dust will cause a large two-car garage sized shop to fail all of the different air quality tests. In other words we make pounds of fine dust yet a fraction of an ounce is enough to create dangerously unhealthy air quality. This fine dust is so light that gravity has little effect except in very still air. Just about any air movement is enough to launch and keep the invisible particles airborne. Once airborne these particles behave more like a gas or bad odor because they rapidly spread to evenly fill all available air. This dust takes a very long time to break down and dissipate, particularly in closed shops. Recall that the Introduction showed an electron microscope image of fine dust from one of the pyramids. Decades of air engineering have found that this fine dust spreads so quickly that once it escapes capture it is near impossible with exhaust fans and air cleaners to clean the air fast enough to keep from failing an air quality test.

Most small shop workers wrongly think that we are not at risk because we buy dust collection equipment with fine filters that leave us with clean looking shops. I learned the hard way that having a clean looking shop is a bad false sense of security. I was rushed to the hospital thinking I was having a heart attack. My emergency room doctors got me stabilized, but as soon as they decreased my medications I went right back into distress. They called in a consulting pulmonary physician. He diagnosed me as having a very bad allergic reaction to fine wood dust. Because this dust was trapped in my respiratory tissues my allergic reaction resumed when my medications were reduced. I argued strongly with my doctor that this could not be a wood dust allergy. I rarely had time to do any woodworking and had done no woodworking in the three prior weeks. My shop always looked clean because I used the magazine "best" rated dust collection system with the "top" rated cyclone with vendor designed and supplied ducting and even their recommended fine filter upgrade. I diligently used a top quality 3M dual cartridge respirator mask whenever making fine dust. Additionally, I had a full panel allergy test just a few months before and it showed no allergies. Allergy testing while I was in the hospital showed with nasty welts and boils that I had very quickly and strongly sensitized to a wide range of woods, many I had never used.

My doctor explained that certain woods, many of which I had recently used to make multicolored Christmas gifts including cocobolo, mahogany, maple, padauk, redwood, rosewood, sandalwood, teak, walnut, and western red cedar all were very strong sensitizers. Some of these like cocobolo and rosewood can create severe allergic reactions in just a few hours exposure. He said what I was actually sensitized to were chemicals that trees use to protect themselves against predators. That meant I was allergic to all the different woods that contained those same chemicals. With my not having done any woodworking in the three weeks prior to landing in the hospital, he suspected that my home had become badly contaminated and I had quite a bit of dust stuck in my respiratory tissues. He strongly recommended I get air quality testing done on my shop and home.

I paid to have the recommended certified air quality testing done on my home and shop. By the time that testing could be done I had not turned on a machine or done any woodworking for nearly four months. I did not expect to see a problem. My home heating, ventilation, and air-conditioning (HVAC) system used some of the best electrostatic filters that money can buy. The testing showed my home badly contaminated with more than double the airborne particles by weight that industrial hygienists recommend which is twenty times more than medical experts recommend. A microscope examination of the particles collected from my home air showed most were fine invisible wood dust particles that passed right through my HVAC filters. My garage based shop tested clean until we turned on the cyclone. Just turning on that cyclone without doing any woodworking launched enough fine dust to cause my shop to fail its air quality tests. My exmainer's particle counter showed most of that dust was blasted out of my fine filter when the blower first got turned on. Twenty minutes of woodworking showed my tools sprayed fine dust all over, my impressive looking dust collection system did not collect most of the fine dust, and that fine filter was a sieve that let the fine dust pass right through. The airborne dust level climbed to over double the maximum allowed government standard which is over 100 times higher than considered safe by medical experts and the Environmental Protection Agency (EPA). The count of the fine invisible particles surged to over 10,000 times higher than considered medically safe. My inspector said my fine dust problem was caused by my small shop vendor selling me something that just plain did not work and posed a serious fire risk. In fact, in my area having a small shop dust collector or cyclone inside in a commercial shop would immediately fail a fire marshal or building inspector inspection. He said most small shop dust collectors and cyclones are such terrible "dust pumps" they should either be vented outside or not used at all. He said most woodworkers would be far safer to work with the garage door opened a little with a good exhaust fan blowing out the side door and wearing a good respirator mask when making fine dust.

My research found many issues combine to create our dangerously high small shop airborne dust levels.

1. Two tiny thimblefuls of this fine dust are enough to cause a large two-car garage sized shop to fail all of the different air quality tests both by weight and particle counts. We can launch this much fine dust by beating our shop apron.

2. Roughly one pound out of every twenty pounds of sawdust we make even when using hand tools is made up of fine invisible dust particles.

3. Our tools lack the hoods needed to contain and control the faster moving air streams so they miss collecting much of the fine dust.

4. Our dust collectors and cyclones move too little air to provide good fine dust collection. Almost all dust collectors under 3 hp and cyclones under 3.5 hp move less airflow than decades of air engineering have shown we need at out tools for good fine dust collection.

5. Most of our ducting and tool ports are too small to carry the needed air volumes.

6. All of the major brand name dust collectors and cyclones provide such poor fine dust separation that they send almost all of the fine dust to their filters. Fine filters will almost immediately clog with typical woodworking fine dust volumes, so our vendors almost all provide filters that freely pass the fine invisible unhealthiest dust.

7. This dust can last for years.

8. The fine invisible fugitive dust we miss collecting just keeps building in shops that vent inside. Almost any airflow is enough to launch this dust airborne and keep it airborne as long as we are working.

In short, the fine filters, dust collectors and cyclones we buy to protect our health are really dangerous “dust pumps” when vented inside that leave us with a false sense of security. These units leave clean looking shops that continue to build dangerously high levels of fine invisible airborne dust. These factors combine so even hobbyists that do minimal woodworking get more fine dust exposure in a couple of hours than those in facilities that vent outside get in months.