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.

Although cleanup of wood dust, shavings, curls and chips known as “chip collection” remains important to avoid fires, slipping, and being able to see as we work, I painfully discovered a dangerous hidden fine dust hazard. Most small shop workers wrongly think we get minimal dust exposure. Frankly our vendors have long lied to us saying woodworking creates very little fine invisible dust when the reality is woodworking generates about one pound of fine invisible dust out of every twenty pounds of sawdust we make. Even those who recognize that even clean woodworking operations such as using a hand plane makes lots of this same fine invisible unhealthy dust, think we are well protected. We buy dust collectors and cyclone separators that come with filters that pull off the larger particles which leave us with clean looking shops. Unfortunately, these systems even with their so called fine filters mostly pump the fine invisible dust that causes the most damage to our health right through.

I learned this the hard way. I used the top magazine rated cyclone based dust collector with vendor designed and supplied ducting plus vendor recommended upgraded filter. That system left a clean looking shop that created a bad false sense of security. I landed me in the hospital from a bad wood dust triggered allergic reaction. Certified air quality testing found the fine dust particle counts in my shop and home thousands of times higher than the EPA considers safe. Now that inexpensive particle meters are available thousands of woodworkers all over the world have discovered that when we vent our dust collectors and cyclones inside we build up dangerously high amounts of fine invisible dust. Even when not making fine dust our shop air contains thousands of times more fine airborne particles than found in commercial facilities that vent outside. A couple of hours working in a shop that vents its dust collection inside generates more fine dust exposure than a worker in a commercial shop that vents outside receives in months working full time. Because this fine dust behaves like a gas and spreads into any connected airspace almost all homes over basement shops and homes connected to garage based shops also test with dangerously high airborne dust levels. After decades of taking care of woodworkers and our family members for wood dust generated health problems often worsened by our using fairly toxic woods my respiratory doctor says small shop workers should make fine dust collection a top priority.

Medical experts define fine dust as inhalable particles sized 10-microns and smaller. A micron is one millionth of a meter and a meter is about 29” long. The picture on the left shows an average human hair of about 70-microns thick compared to 10-micron dust particles. We need magnification to see particles sized 10-microns and smaller, so fine dust particles remain invisible. Fine dust causes so many health problems that researchers and health experts study them extensively. Researchers use shorthand names for three particle size classes. They use PM-10 for particles sized smaller than 10 microns, PM-5 for particles sized under 5-microns and PM-2.5 for particles sized under 2.5-microns.

Government studies show fine dust makes up one pound of every twenty, roughly 5% of the woodworking dust we make. Fine wood dust remains so light that normal room air currents overcome the effect of gravity and keep this dust airborne except in very still air. Just about any air movement will launch and keep fine wood dust particles airborne. Fine wood dust behaves more like a gas or bad odor because it rapidly spreads to evenly fill all available air. Fine dust particles readily move from basement shops to our homes and frequently follow us through doors that connect our homes to our shops. This dust also readily travels in our hair, on our skin and on our clothes. Wood gets much of its strength from silica better known as glass, so this high silica content means fine wood dust takes a very long time to break down and dissipate. So, once we have a wood dust contamination problem that problem stays with us until we do a thorough cleanup.

We need to know the odds of anything happening to us to decide how much if any protections we want to provide. The damage caused by fine dust depends upon overall health, genetics, type of exposure, amount of exposure, frequency of exposure, and duration of exposure. The higher, longer and more frequent our exposure the greater the harm. Doctors call this a dose response relationship. Almost all medical studies that give the different probabilities of harm studied health insurance data for woodworkers in large facilities that vent their fine dust away outside. The health insurance data show at typical exposure levels for shops that vent outside 100% of workers develop a significant loss in respiratory volume, about 14% are forced into an early dust related medical retirement, about 7% develop such bad sensitivity (allergies) that they must permanently give up woodworking, and about half of one percent develop dust related cancer. For the large facilities that voluntarily met the Department of Labor, Office of Safety and Health Administration (OSHA) recommended air quality standards the number forced into an early fine dust related medical retirement drops to one in fourteen.

This is really bad news for small shop workers because most small shop workers receive far higher exposures. Government air quality testing shows shops that vent inside average two to five times higher airborne dust levels than shops that vent outside. As small shop users we make far less dust, but most of us vent our dust collectors and cyclones inside through filters that do not separate off the unhealthiest fine invisible dust. This rapidly builds and cycles the fine dust until most small shops have dangerously high airborne fine dust levels. Worse, our filters pull off the larger particles and freely pass the fine invisible particles known to cause the most health problems. We rapidly build the fine invisible particles that cause the most damage to our health. We make this fine dust by the pound, yet only a couple of small thimblefuls of are enough to cause a large two-car garage sized shop to fail all of the different air quality tests. As a result, even hobbyist who do little woodworking often end up with a higher dust exposure in a few hours work than a full time large facility professional woodworker gets in months. Although we found no medical studies run on small shop workers, my respiratory physician said his experience from decades of practice convinces him that small shop workers, hobbyists, our families and even our pets often suffer the most and worst fine dust triggered health problems.

Although politics blocked enforcement of the 1998 OSHA air quality standard, other concerned organizations recommend much tougher standards for commercial woodworking shops. The American Council of Governmental Industrial Hygienists (AGGIH) recommends an air quality standard five times tougher than OSHA. Medical experts consider both the OSHA and ACGIH standards far too low. They recommend a standard that is fifty times tougher than OSHA. The European Union agreed and the Environmental Protection Agency (EPA) agree and both set standards at about fifty times the OSHA standard. So how do we make repair to amply protect ourselves?

Most incorrectly think we can eliminate our fine dust problems by wearing a good dual cartridge filtered mask like the 3M 7500 series whenever we make fine dust. Others, including me foolishly believe that if we buy and install a good dust collector or cyclone with fine filters that we will end up well protected. A good respirator mask like this is a must because some shop activities create more dust than we can control. Likewise, a good dust collector or cyclone also helps, but we still need to do more things to ensure we do not contaminate our offices, homes, and vehicles. To understand well enough to get our fine dust controlled we need to know a little more about dust collection. Here are some of the reasons why good fine dust collection poses more difficulty and expense than getting good chip collection.