Medical Risks

Access to the information to make an informed decision is rapidly vanishing. When I started this work in 1999 the various health care insurance companies as a public service shared their data and summary information as did many universities, professional organizations, and governmental agencies. Today most only find a confusion of mostly second hand information. The once freely published standards from the various professional organizations are now prohibitively expensive for typical small shop woodworkers. The freely shared testing and medical study results are now mostly also charge items. The huge amounts of insurance data shared on the Internet vanished. My follow up calls to the main medical insurance companies were met with diversions. I called a friend who manages one of the larger health care insurance firms and he was pretty blunt. The insurance firms set their rates to provide the needed services and still show a profit. If people are healthier they can lower rates, so they freely shared data that showed all kinds of behaviors that have clear long term negative effects on our health and life spans. Wood dust is just one of many things they know has a big long term effect on the cost of providing health care, particularly in the later years. Although this sharing seemed well and good, in many areas it suddenly provided the fuel to create potential untold liability damage to those firms paying the medical insurance premiums. The medical insurance companies chose to stop the sharing rather than lose the firms paying the premiums. With the 2000 U.S. census showing woodworking is the fourth largest employer it is no wonder that private and government efforts to make repair are being done very quietly and carefully.

This leaves a confused mess of contradictory information. The large woodworking concerns have flooded the Internet with very authoritative studies often from prestigious universities that counter just about every aspect of there being any real short or long term danger from exposure to fine wood dust. Small shop woodworkers have to guess from what appear to be equally authoritative sources saying woodworking dust is dangerously unhealthy, others saying this dust is modestly unhealthy, and others saying woodworking makes no fine dust and there are no short or long term risks from fine dust exposure. With the worst dust being invisible and until recently the equipment to do our own testing was prohibitively expensive leaving most small shop workers guessing what information is accurate, then based on our guesses try to provide ample protection.

Complicating this mess even more are our small shop vendors. The competition to be the vendor of choice in this rapidly expanding market is beyond fierce. With almost all knowing little about dust collection including most of the vendors, what happened is these vendors copied and downsized traditional large facility dust collectors and cyclones. The original equipment was carefully engineered for outdoor use with cyclones designed to separate off the heavier chips and sawdust then blow the fine dust away outside where it quickly dissipates. Likewise dust collectors came with open filters that also passed this same fine dust to blow away outside. In copying and downsizing this equipment the small shop vendors did so without any concern about it being illegal in almost all areas to use this equipment inside in facilities subject to fire marshal inspection due to fire and explosion risks. These downsized dust collectors and cyclones vented 100% of the fine airborne dust inside building huge amounts of fine dust that coated everything. When too many began getting ill from this high dust exposure a few firms started making good money by selling finer filters. Although these finer filters get rid of the visible dust they create a bad false sense of security because they mostly freely pass the finest unhealthiest invisible dust. These filters are mounted on dust collectors and cyclones that do not move enough air for good collection and most of these units are plumbed with ducting far too small to carry the needed airflow.

The only real oversight on our small shop vendors is what we exercise with our buying decisions. Finding the time to gather the information needed to make informed purchasing decisions is tough and only made more difficult by our vendors. Most tend to rely upon the magazines they trust and word of mouth mostly through the Internet forums. What most do not realize is the main vendors pay not only for the magazines, they also provide most of the support including the salaries for the moderators on even the vendor free forums, plus these vendors pay both moderators and more established posters to recommend their products. As a result, much of the advice we get is directly from the vendors. They are focused on selling equipment and continue to push the positive traits of what they have to sell while ignoring the negative. Frankly, neither dust collectors nor cyclones have evolved much at all since 1999. They still almost all move far too little air, provide little better separation than a $25 trashcan separator lid, and cause small shops to create fine invisible airborne dust levels far worse than if we worked with a door open and exhaust fan blowing outside.

Although woodworking creates little carbon monoxide, my respiratory doctor said woodworkers often suffer carbon monoxide poisoning. Burning wood, charcoal, coal, natural gas, propane, methane, gasoline, oil, and other fossil fuels creates carbon monoxide. Almost everyone has many carbon monoxide producing sources close by including our vehicles, furnaces, propane heaters, stoves, ovens, gas driers, BBQs, charcoal grills, water heaters, etc. Each comes with instructions to ensure their safe use. Unfortunately our dust collection can make these normally safe sources of carbon monoxide dangerous. Most small shop woodworkers do not realize our dust collectors, cyclones, blowers, and exhaust fans are so powerful that they often suck deadly carbon monoxide into our shops and homes backward through vents and from nearby normally safe carbon monoxide sources. This leaves us at high risk of severe short and long term carbon monoxide poisoning.

Carbon Monoxide is a colorless odorless poisonous gas. Carbon monoxide keeps our red blood cells from carrying oxygen. The loss of oxygen shuts down our nervous systems similar to the effects of alcohol so we cannot tell when we are exposed until too late, so carbon monoxide kills thousands of people in the U.S. yearly, more than all other poisonings combined. How ill we get depends upon age, overall health, exposure amount, and exposure time. More serious carbon monoxide poisoning produces mild flu like symptoms that progressively worsen including drowsiness, exhaustion, headache, dizziness, changes in body temperature, changes in blood pressure, loss of appetite, pain in extremities, loss of coordination, nausea, vomiting, disorientation, difficulty breathing, irregular heartbeat, chest pain, visual disturbances, hallucinations, tremors, convulsions, suffocation, and coma. Unfortunately, up to 40% of those who suffer serious carbon monoxide poisoning and many who are exposed to lesser amounts for long periods, including small shop woodworkers, end up with permanent health damage. Often the initial symptoms become permanent plus many later develop eye damage, hearing loss, blood disorders, heart damage, nerve damage, numbness, brain damage, amnesia, memory loss, behavior changes, Parkinson like tremors, and birth defects. Clearly when things go wrong we cannot tell without a detector when we are breathing in carbon monoxide until too late. My doctor strongly recommends installing, using and maintaining carbon monoxide detectors in our homes and shops. I recommend that if you vent your dust collection outside that you also provide an opening to outside for makeup air that is at least twice the diameter of your ducting going outside. That makeup air will keep our equipment from sucking the fumes backward from our vents.

Wood dust poses a serious fire hazard with most shop fires occurring from sucking up something hot such as a cigarette or hot piece of cut metal such as a freshly cut staple or nail that lands in our dust bin creating a smoldering fire that often breaks out hours after we leave our shop. At one time aluminum impellers were recommended, but now NFPA recommends against them because when hit by a piece of steel they launch a spark just like a sparkler or a steel blower wheel when it by a piece of steel. It is always a good idea to first use a big magnet to ensure you do not suck up debris that can cause sparks.

This fire danger is why I only recommend metal dust bins and remain strongly opposed to the light cardboard bins that most small shop vendors now provide with their cyclones. This is also why the National Fire Protection Association (NFPA) sets firm rules that require commercial firms only use certified fire and explosion proof dust collectors and cyclones or place these units outside. Specifically the NFPA Standard 664 "Prevention of Fires and Explosions in Wood Processing and Woodworking Facilities" Chapter 8, Woodworking Dust-Control Systems, Section 2.2 states, "Dust collectors shall be located outside of buildings." Two exceptions are listed which permit dust collectors to be located inside of buildings:

1. If they are located adjacent to an exterior wall, or vented to the outside through straight ducts not exceeding 10 feet (3 meters) in length, and have explosion vents.

2. If protected by an explosion suppression system meeting the requirements of NFPA 69, Standard on Explosion Prevention System.

Clearly those small shop vendors who fail to warn their customers that their dust collectors and cyclones are not certified and not suitable for safe indoor use are doing customers a major disservice. Those vendors who say they provide professional grade equipment are frauds if they sell dust collectors and cyclones with plastic and cardboard dust bins. Many woodworkers as they turn pro and expand their shops get startled to learn their expensive cyclones will not pass a building or fire marshal inspection in most U.S. areas.

Now as a practical matter most small shop woodworkers do put their dust collectors and cyclone separator systems indoors. We need to fully understand that putting our dust collectors and cyclones inside greatly increases our risk of fire. Most small shops make too little dust at one time to have an explosion risk; however, when we vacuum up a large pile of very fine dust that cloud can become explosive and get touched off by a nail or other metal item striking either a steel or aluminum impeller.

Unfortunately, bringing our dust collectors and cyclones indoors generates a much worse problem. When outside these units vent the fine invisible dust outside where it quickly dissipates. When vented indoors we often build up such huge concentrations of fine dust that just walking through our clean looking shops will stir up enough fine dust that we will fail an air quality test without doing any woodworking.

My respiratory doctor helped with his own summary. He said most small shop woodworkers leave dust collection as one of our last priorities, but protecting ourselves from fine wood dust should be one of our first because wood dust is so dangerous.