Medical Risks

Created: November 20, 2000
Updated: July 11, 2020

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Summary
This page shares general shop safety risks, a few serious risks many do not know about, and far more detail of the risks of fine dust. It presumes you have already read the Introduction and Dust Collection Basics pages.
Information Availability
The available information to make informed dust collection decisions was an overwhelming controversial mess. There were over one hundred million fine dust health references and many disagreed. There were tens of thousands of references on wood dust collection and most disagreed. Even different government organizations such as OSHA and the EPA had strongly differing views. I needed help for it to make sense. My doctor had me focus on the peer reviewed medical research which has been verified by expert physician specialists before publication. My air engineering professor had me focus on the engineering information provided by the major firms who supply dust collection systems and guarantee customer air quality. If we stay with just the peer reviewed medical information and solid well tested engineering information that leaves what we need to build dust collection systems that provide good health protection. Rather than discuss this controversy throughout these pages, this long involved mess was moved it over to its own page, Research Trials. Those pages share more information than you probably will ever want to know about some of the frustration involved in researching and sharing good fine dust collection information.
Good Shop Safety
Before diving more into dust collection, first a few words on general shop safety. You should not ignore good shop safety practices. There are too many ways that woodworking can hurt us through inattention, ignorance, neglect and accidents. The U.S. Consumer Product Safety Commission in 2003 found power tools and workshop equipment injured over 1.3 million people in the U.S. enough to require emergency room or doctor treatment. One of my favorite magazines, Fine Wood Working published by Taunton Press, includes the following caution in every magazine issue, "Working wood is inherently dangerous. Using hand or power tools improperly or ignoring standard safety practices can lead to permanent injury or even death. Don't try to perform operations you learn about here (or elsewhere) until you're certain that they are safe for you. If something about an operation does not feel right, don't do it. Look for another way. We want you to enjoy the craft, so please keep safety foremost in your mind whenever you're in the shop." Most agree with this warning because we can look at a powerful or sharp tool that cuts hard wood like soft butter and know we need to be careful.

For the most part, learning shop safety is fairly easy. I personally like the ABC approach, Always Be Careful, but being careful requires us to also be knowledgeable of the risks and proper usage. Our tools rarely come with good safety and usage instructions but there are lots of books, videos, classes, government publications, and Internet presentations that share how to safely use our tools. In my first woodworking classes in the fifties we were taught safely rules for every hand and power tool. We were required to use push sticks or power feeders whenever using a powered blade, bit, or cutter. We had yellow lines around each of the power tools that were no entry zones for all but the operator. We had red zones for potential kickback where even the operator should not go. We had a rule to immediately sweep up all sawdust to make sure that nobody got hurt from a slip. We even had a rule about putting sawdust and used rags only in sealed metal cans to prevent fires from spontaneous combustion. Likewise, we had rules to read and follow the product information sheets that share how to safely use hazardous things including solvents, paints, varnishes, stains, glues, epoxies, fiberglass, acids, bleaches, solder, etc. For most hazardous things these sheets said to wear a good properly fitted cartridge filtered respirator mask and heavy rubber gloves then work outside or in a "clean room" with strong exhaust fan and hood. You can and should go to the library, use the Internet, and take classes to learn to use your tools safely. Frankly, little of the basic tool safety rules has changed since my father, a master woodworker, taught me that sweeping up right away made for a safer, more pleasant shop with less risk of fire or slipping near dangerous tools. The U.S. Department of Labor, Guide for Protecting Workers from Woodworking Hazards and the Health and Safety Executive web pages share many good woodworking safety practices and are recommended reading for all.

At first there was very little published on protecting ourselves from wood dusts. One of the first wood dust safety rules is to avoid blasting yourself with a spray of sawdust and chips. As you will read shortly wood dust and the chemicals associated with wood can be very dangerous. This sprayed dust contains larger particles which can give us larger doses of these unhealthy chemicals. This sprayed dust can also give us splinters, coat our skin, get in our eyes, and load up our respiratory systems. This high dust exposure greatly increases our risks of developing irritation, infections, allergies, cancer, and long term respiratory system damage. Always work in such a way that dust streams are directed away from you and never get yourself in a position where you end up breathing a blast of dust. Unfortunately, many tools make following this advice difficult. For instance, the normal spot to stand when using our table saws puts us right in the blast of dust that comes off our saw blades. As you will find in the following Dust Collection Basics pages, we need to upgrade almost all tool hoods to block, control, capture and deliver these blasts of dust. More of fine dust safety is discussed below.
Carbon Monoxide Poisoning
Although woodworking creates little carbon monoxide, my respiratory doctor and the medical emergency room statistics show 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 flues from nearby normally safe carbon monoxide sources.

Carbon Monoxide is a colorless odorless poisonous gas. It prevents 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.
Fire & Explosion Safety
Wood dust poses a moderate but serious explosion hazard. Fine wood and metal particles become very explosive when enough are mixed with air. The good news is unless we intentionally throw a large amount of fine dust into the air, most small shops make too little dust at one time and generate too little static electricity to trigger an explosion.

Wood dust poses a much more serious fire hazard. Most small shop fires occur when sparks, cigarettes, hot pieces of cut metal, sparks, etc. land in piles of sawdust on our floors, our dust bins, dust filled ducts or dust filled filters. The high airflow inside our dust collection systems can quickly cause a fire. Sparks in dust bins can smolder for hours then break into a fire long after we leave our shops. Most small shop fires start in dust piles and dust collection bins, so it is always a good idea to clean up dust piles and use metal fire proof collection bins.

Woodworking makes lots of sparks, but most are so small they are not a problem. We get static electricity sparks from a buildup of static at our machines, ducting, dust collection and filters. Unlike larger shops it is almost impossible for these electrical sparks to be powerful enough in small shops to trigger a fire or explosion. Still, static shocks can be very dangerous if we get shocked when working close to fast moving blades, bits and cutters, so good static protection is a must particularly in cold dry weather. Our fast moving blades, bits and cutters create sparks when we work wood, especially knots and high silica content wood. A friend made a video of a table saw cutting hardwood in the dark. It looked like he was grinding a piece of steel as sparks flew off the blade all over. Fortunately, these sparks are almost all so short lived they rarely could cause a fire.

Woodworking also produces longer lived far more dangerous sparks and hot pieces of metal. Grinders and sanders when working steel or aluminum make long lived sparks so you should never use these with vacuums or dust collection systems also used to collect wood or other flammable dust. We also get long lived sparks if our tools hit staples, nails, screws or other pieces of metal. This is another good reason to check suspect wood with a nail finder before processing. Metal pulled through our dust collection system can slam into dust collection components hard enough to also create long lived sparks. We also get bad sparks when our fast moving blower impellers hit a piece of steel or aluminum. Most good big vacuum floor pickups have built in magnets to catch steel and iron bits before they get sucked through our dust collection systems. If a longer lived spark lands in a pile of sawdust the air in our dust collection systems can quickly fan it into a bad fire. If longer lived sparks land in dust piles, dust bins and even dusty filters, they can create fires that smolder for hours before finally bursting into a nasty fire long after we have left our shops.

These fire dangers are why the National Fire Protection Association (NFPA) who writes the codes most fire marshals and building inspectors follow have lots of formal rules to prevent fires. Good work practices and most local codes require that floors, tools and work surfaces have ample dust collection to stay clear when in use. This helps avoid falls from slipping, lets us better see our work, keeps our blades, bits and cutters visible, and keeps sparks from landing in nearby piles of dust. The NFPA requires use of only metal duct in spite of many using PVC and other materials. At one time the NFPA only allowed aluminum blower impellers, but now NFPA recommends against aluminum impellers. When hit by a fast moving piece of steel aluminum launches large white hot aluminum sparks just like a sparkler. Most small shop woodworkers put their dust collectors and cyclone separator systems indoors, but putting our dust collectors and cyclones inside greatly increases our risk of fire. Our small shop vendors do us a double disservice with their current cyclones and dust collectors. Their plastic bag and cardboard dust collection bins will not contain a fire or ever pass fire marshal, building inspection, or insurance agent inspection. If we want extra insurance or to go professional and pass an inspection, we have to buy new units. Worse, even with upgraded bins, these units are still not fire and explosion certified, so they have to be moved outside behind fire and explosion proof barriers. 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.
Fine Dust
By definition fine dust particles are so small they are invisible without magnification. Fine dust particles are so light and have so much surface area compared to their weight that normal room air currents will keep fine dust airborne and rapidly spread it through all shared air. Even very light airflow will stir settled fine wood dust particles airborne again and again. Based on the peer reviewed medical research that shows serious health problems from inhaling fine dust, the EPA sets really tough airborne dust limits, can shut down monitored buildings and not allow them to reopen until the air quality is restored. Fine airborne dusts are so unhealthy the EPA indoor air limit for fine dust is only 0.1 milligrams per cubic meter. Most small shops are in typical two-car garages with no ventilation and less than 100 cubic meters of air. This means a typical small shop exceeds the EPA air quality limits as soon as 10 milligrams of fine dust gets launched airborne. This is a tiny amount of fine dust. We easily launch more than 10 milligrams of fine dust when we slap a dusty shop apron or hand saw just over seven inches of a typical 3/4" thick board.
Small Shop Dust Exposures
Most small shop woodworkers wrongly assume we have little risk and small exposures, but OSHA testing clearly shows most small shop workers get more fine dust exposure in a few hours woodworking than large facility workers get in months of full time work and we frequently work more toxic woods, so have higher more dangerous toxic chemical exposures. Unlike almost all large woodworking facilities that vent their dust collection outside where the fine dust blows away and organisms quickly break it down when it gets wet, most small shops vent our dust collection systems inside. Because wood gets much of its strength from silica better known as glass it takes nearly forever to break down. Wood dusts last so long that many got ill from exploring pyramids due to many thousand year old wood dusts trapped inside. OSHA testing shows on average every twenty pounds of woodworking sawdust also makes enough fine dust to cause 15,119 typical two-car garage sized shops to fail an EPA air quality test. Every 1% we miss collecting adds enough additional dust to cause another 151 typical small shops to fail an EPA air quality test. Most small shop air cleaners, vacuums, dust collectors and cyclone systems collect the visible dust to leave clean looking shops which creates a bad false sense of security because most of these units lack ample airflow and fine enough filters so miss collecting at least 15% of the fine dust made. This means venting inside causes every twenty pounds of sawdust to add enough fine invisible dust to our shops to cause 2,267 more average two-car gargage sized shops to fail their air quality tests. The fugitive dust that escapes collection rapidly builds such dangerously unhealthy levels that OSHA air quality testing finds most even very clean looking small shops that vent their dust collection systems inside build up so much fine invisible dust that just walking around without doing any additional woodworking launches enough fine dust airborne to fail an EPA air quality test. These very high small shop dust levels should terrify most small shop workers because the peer reviewed medical research is clear that the higher the exposure the greater the damage. My respiratory doctor provided a simple summary. He said most small shop woodworkers leave dust collection as one of our last priorities, but protecting ourselves and those close to us from fine wood dust should be one of our first because wood dust is so dangerous.
Health Effects
The following covers many of the main adverse health effects we get from working wood and apply whether we are talking large bloards or fine dust.
1. Particle Damage
  Fine dust particles of all types are often called inhalable dust because these particles are so small they slip right past our natural protections then go deep into our respiratory tissues where they damage and scar our tissues. The smallest inhaled particles can go from our lungs directly into our blood and affect our bodies all over. Inhaled fine dust particles are well researched and so heavily studied researchers call them PM short for particle material. A Google search on "PM Health Risks" gives more than 100,000,000 references. The peer reviewed medical research shows the respiratory damage is so slow most don't notice as it occurs, but every exposure to fine dust of all types causes a measurable reduction in respiratory capacity, some of this reduction becomes permanent, the higher and longer the exposure the greater the damage, and the damage builds to cause many serious short and long term health problems. Based on this solid medical research the EPA sets really tough limits for all airborne dusts.
  
  Fine wood dust particles are one of the worst airborne dusts. The existing studies focus on large facility woodworkers where most of the dust is blown away outside and workers rarely work the more toxic woods. At a microscopic level wood behaves like a stack of glued together fine glass tubes. When our blades, bits, cutters, or sandpaper work wood these tubes shatter and millions of fine wood dust particles get launched airborne. A particle counter shows even when using a razor sharp hand plane that makes no visible dust we launch millions of fine invisible wood dust particles. Woodworking makes huge amounts of fine dust compared to how little it takes to harm our health. OSHA testing shows on average with every twenty pounds of woodworking sawdust we also make enough fine airborne dust to cause 15,119 typical two-car garage sized shops to fail an EPA air quality test. Electron microscope images show fine wood dust particles are covered with razor sharp edges and extended sharp often barbed points which damage and scar our tissues. These shapes also make it very difficult for our bodies to get rid of fine wood dust particles and cause them to get lodged trapped deep in our tissues. Wood dusts contain and carry toxic chemicals that these trapped particles can release for an extended time. As you can see in the below Wood Toxicity Table many woods contain chemicals that can be poisonous, cause us to develop pneumonia, increase our risk of cancer, badly irritate our eyes, skin and respiratory systems, and are sensitizers meaning we build allergic reactions sometimes in as little as a few hours of exposure. One of the better overviews of wood dust risks is the United Kingdom Health & Safety Executive (HSE) Toxic Woods - Woodworking Sheet No. 30. To set rates insurance companies accurately track worker injuries and medical problems. Insurance companies used to share their data, but most is no longer available because too many used this information to sue employers. The previously shared insurance data on large facility woodworkers showed a tiny number get poisoned and develop cancer, one in seven develop such bad allergic reactions they must stop woodworking, one in fourteen has such bad wood dust triggered health problems they are forced into an early medical retirement, almost all lose about 1% of their respiratory capacity per year of work, and woodworkers have shorter life spans.
2. Wounds
  Splinter wounds, cuts and eye injuries from a number of woods are slow to heal and often turn septic, e.g. greenheart, mansonia and redwood. This is partly due to toxins from the species involved and partly due to secondary infections from bacteria and fungi entering through the skin.
3. Poisons
  Some woods are poisonous, treated with very toxic chemicals or carry mold toxins which are extremely poisonous. Lots of plants develop strong chemicals for protection from bugs and predators, plus keep away plants that would otherwise compete for food, water, and sunlight. Most of us know from bad experiences with poison oak and poison ivy that some plant chemicals can be nasty. Working poisonous woods such as hemlock, mandrake root, mimosa, oleander, poison ivy, poison oak, sassafras, yew, etc. can make us very sick and even kill us. Often treated wood, painted wood and insecticide covered wood will also contain toxic chemicals. Enough contact or inhalation of toxic chemicals can create a variety of health problems including illness, vomiting, heart and chest pain, anemia which leaves our cells oxygen starved, kidney and liver disease, neurological damage and even death. Many woodworkers get accidental toxic chemical exposures when trying to make small items such as turned pens and such from exotic woods, stems of interesting looking woods and bushes, and highly treated woods.
4. Irritants
  Many plants also contain chemicals which may not be outright poisonous but are strong irritants that can quickly make us feel miserable. Working with irritating woods can cause violent sneezing, rhinitis (runny nose), nose bleeds, blocked nose, coughing, respiratory problems, asthma, impaired lung function, rare flu like symptoms that cause progressive lung damage, sore eyes, conjunctivitis (watery or prickly eyes), rashes, dermatitis (dry itching and cracking skin), and stomach upset. Irritation can, in some species of wood, lead to nettle rashes or irritant dermatitis. These effects, from direct contact or cross-contamination to other parts of the body by hand, tend to appear on the forearm, backs of the hands, the face (particularly eyelids), neck, scalp and the genitals. On average, symptoms take 15 days to develop. Symptoms usually only persist as long as the affected skin site remains in contact with the source of irritation such as the wood dust or sap etc. Symptoms subside when contact with the irritant is removed. All these can develop into other more serious problems such as chronic incurable runny noses, sinus infections, pneumonia and even hepatitis.
5. Sensitizers
  Many woods contain sensitizing agents that cause us to build up allergic reactions. Most allergic reactions are studied for large commercial facility woodworkers where they rarely use exotic woods. Even so, the insurance data show one in seven large facility woodworkers becomes so sensitized they must either give up woodworking or stop working with certain types of woods. Most wood triggered allergic reactions are on our skin, but the most dangerous affect our respiratory systems. Some common sensitizing woods include birch, oak, maple, red cedar and walnut, but many small shop woodworkers often use more exotic woods. There is not that much data on the exotic woods, but cocobolo, ebony, mahogany and rosewood have proven to be such strong sensitizers that some develop strong allergic reactions after just a single exposure. Fortunately, most woods are only mild sensitizers, and our bodies do a pretty good job of handling the mild sensitizers unless we have very long term or constant exposure such as from a contaminated home or office. Then, just like the stronger sensitizing woods, we can build dangerous allergic reactions. How quickly we become sensitized depends upon the strength of the sensitizer, our amount of exposure, how long we are exposed, and our individual health. The resulting respiratory allergic reactions can vary from mild sore throat, headache, asthma, sinus pain and cold like symptoms, to chronic eye, ear, nose, sinus, throat and lung irritation which invariably leads to infections. If the exposures are allowed to continue the attacks can be potentially life threatening with anaphylactic shock where our airways close down and we can die without immediate medical help. Those who become strongly sensitized automatically become sensitized to all the different species of wood that contain the same sensitizing chemicals meaning we become allergic to woods we have never previously used. Worse, those who become sensitized often develop cross-sensitization where we have allergic reactions to many other woods and even non-wood materials that contain different sensitizers.
6. Carcinogens
  The more and larger particles we inhale the higher our exposures to some of the chemicals which are known to increase the risk of cancer. Fortunately, the risk is small, roughly 7 in 10,000 and most wood dust related cancers are in the mouth, nose, sinuses and throat where they can be treated successfully if caught early.
7. Silicosis
  According to Wikipedia, "The chemical composition of wood varies from species to species, but is approximately 50% carbon, 42% oxygen, 6% hydrogen, 1% nitrogen, and 1% other elements (mainly calcium, potassium, sodium, magnesium, iron, and manganese) by weight. Wood also contains sulfur, chlorine, silicon, phosphorus, and other elements in small quantity". Wood gets much of its strength from silica which is the main component in glass. Some of the harder woods can contain over 1% silicon by weight. While the organic components in wood break down slowly, the silicon and carbon structures linger nearly forever and can cause all kinds of damage throughout our bodies similar to fiberglass and diatomaceous earth. Both silica and carbon fibers join a handful of other toxic exposures such as tobacco smoke, dioxin, and asbestos which cause multiple serious diseases. We rarely feel much with each exposure, but over time the damage builds to bad news and may even cause scaring and silicosis. Silicosis and scaring cause many symptoms including Dyspnea (shortness of breath) exacerbated by exertion, frequent persistent severe cough, fatigue, tachypnea (rapid often labored breathing), loss of appetite and weight loss (anorexia), chest pain, fever, gradual darkening of skin (blue skin), gradual dark shallow rifts in nails eventually leading to cracks as protein fibers within nail beds are destroyed. In advanced cases, we also see cyanosis, pallor along upper parts of body (blue skin), cor pulmonale (right ventricle heart disease), and respiratory insufficiency. Evidence in recent years also indicates that silica exposure not only destroys our lungs, livers and kidneys but also causes lung cancer and probably renal disease. There is also strong suggestive evidence that silica can cause arthritis and other auto-immune diseases.
8. Diseases
  Additionally, there are some common diseases identified and associated with fine dust exposure, particularly wood dusts. Below is a copy of government information with descriptions of the major wood related illnesses
  1. Sensitization dermatitis
    Sensitization dermatitis is more problematic and is usually caused by skin exposure to fine wood dust of certain species. Rashes can appear on skin well away from the original point of contact. This is also referred to as allergic contact dermatitis and results in similar skin effects to those produced by skin irritants. However, once sensitized the body sets up an allergic reaction and the skin may react severely if subsequently exposed to even very small amounts of the wood dust. Cross-sensitization may develop where other woods or even non-wood materials produce a similar response.
  2. Fibrosis
    The primary long term disease risk from wood dust is fibrosis which comes from the long term damage from very fine dust particles. The U.S. Environmental Protection Agency (EPA) in their EPA Fine Particulate Matter National Ambient Air Quality Standard says fine dust particles sized 2.5-microns and smaller pose significant long term risks, "Health studies have shown a significant association between exposure to fine particles and premature mortality. Other important effects include aggravation of respiratory and cardiovascular disease (as indicated by increased hospital admissions, emergency room visits, absences from school or work, and restricted activity days), lung disease, decreased lung function, asthma attacks, and certain cardiovascular problems such as heart attacks and cardiac arrhythmia. Individuals particularly sensitive to fine particle exposure include older adults, people with heart and lung disease, and children."
    
    The accumulation of fine wood dust in our airways and lungs creates long term problems similar to asbestos, silicon and fiberglass inhalation. A buildup of these fibers in our nose, sinus, throat, and lung tissue over time causes damage where our airways slowly close down from being filled with fibers and scar tissue. That makes sense because trees get much of their strength from silica better known as glass, plus wood is made up of the same kinds of fibers that cause these other problems. The medical research is clear there is no safe level of wood dust exposure because every fine wood dust exposure creates some measurable damage and some of this damage becomes permanent. The amount of damage depends upon our general health, how much we take in and for how long.
    
    Enough exposure over time creates serious permanent damage. Like smoking, the changes are so slow most do not realize they are developing a problem until they become seriously ill. The insurance and medical research data show that most woodworkers will go ten or more years before becoming aware of any symptoms (just as many can smoke tobacco for years with no apparent symptoms). That applies to factory woodworkers who average two to five times less than small shop woodworkers. At small shop airborne dust exposure levels most will have enough damage eventually to adversely affect the quality of our lives with roughly one in eight ending up with such serious medical problems they are forced into early medical retirement.
  3. Dry rot HP
    Dry rot HP (Hypersensitivity pneumonitis) is an acute and/or chronic condition with acute presentation: flu-like illness with cough; Subacute: recurrent "pneumonia"; Chronic: exertional dyspnea, productive cough, and weight loss; Most patients have abnormal imaging studies (chest x-ray or high-resolution CT). Crepitant rales are heard in some cases. Pulmonary function testing shows a restrictive defect in early disease and a restrictive, obstructive or mixed defect in late disease. Precipitating antibodies are neither sensitive nor specific, and their presence is no longer considered a hallmark of HP. Some patients have decreased diffusion capacity and arterial hypoxemia. If the diagnosis is in doubt, bronchoalveolar lavage (BAL) typically shows lymphocytosis. Surgical lung biopsy may be indicated if bronchoscopy is nondiagnostic. The disease latency varies from a few weeks to years after first exposure. Symptoms appear or worsen within a few hours of antigen exposure to bioaerosols of microbial or animal antigens or rarely to a few reactive chemicals. Complete recovery usually occurs if exposure is terminated early. Otherwise, the disease may progress to interstitial fibrosis. [Murray, p. 1783-1799]
  4. Organic dust inhalation fever
    Organic dust inhalation fever is a moderate to acute condition with Symptoms: flu-like illness with cough preceded by eye and nasal irritation; Signs: leukocytosis; normal chest x-ray; Onset after exposure: 4-8 hours; Heavy exposure to: dusts from organic matter such as moldy hay, silage, compost, or wood chips; Resolution: within two to three days; Comments: As for other inhalation fevers, the treatment is supportive only.
  5. Sequoiosis
    Sequoiosis is a chronic condition with acute presentation: flu-like illness with cough; Subacute: recurrent "pneumonia"; Chronic: exertional dyspnea, productive cough, and weight loss; The exposure is to moldy wood dust, and the suspected antigen is the fungi, Graphium, Aureobasidium pullulans. [Harber, p. 202] See "Hypersensitivity pneumonitis, chronic" and "Hypersensitivity pneumonitis, acute."
  6. Tree cutter lung
    Tree cutter lung is a chronic condition with acute presentation: flu-like illness with cough; Subacute: recurrent "pneumonia"; Chronic: exertional dyspnea, productive cough, and weight loss; The exposure is to wood chips from living maple and oak trees, and the suspected antigens are Penicillium (three species), Paecilomyces sp., Aspergillus niger, Aspergillus sp., and Rhizopus sp. [See Reference Link] See "Hypersensitivity pneumonitis, chronic" and "Hypersensitivity pneumonitis, acute."
  7. Wood trimmer lung
    Wood trimmer lung is a chronic condition with acute presentation: flu-like illness with cough; Subacute: recurrent "pneumonia"; Chronic: exertional dyspnea, productive cough, and weight loss; The exposure is to moldy wood trimmings, and the suspected antigen is the fungus (Rhizopus species). [Harber, p. 202] See "Hypersensitivity pneumonitis, chronic" and "Hypersensitivity pneumonitis, acute."
Wood Toxicity Table
The medical research makes it clear we should never work with woods that we don't know about their possible dangers. I looked for a thorough current list of the potential ill health effects from woods. Although there were many wood toxicity tables, most are copies of each other with a few minor changes and upgrades. Most of these charts and tables are based on work done by Roy Banner, a wood turner from Torrance, California who almost lost his life in 1989 to anaphylactic shock after turning pieces of exotic wood. One of the more current and complete wood toxicity tables can be found at HEALTH HAZARDS & WOOD shared by the Woodworking Australia web pages. I found that the existing charts date back mostly before 1990, so I did the research and built the more current below Wood Toxicity Table. This table provides a pretty good overview of the potential health effects from working with most readily available woods. Realize it is incomplete because many woods that are of relatively limited distribution have never been analyzed for toxins. Also, every woodworker may experience different reactions with different intensities, so please always wear a mask whenever working with any known toxic woods. I recommend you wear a good dual cartridge respirator mask any time you make fine dust and that you leave your mask on whenever in your shop until after you have thoroughly cleaned out your shop of all the fine residual dust. Our particle meters show to get rid of the fine dust we have to thoroughly blow out our shops while we run a strong fan blowing out a back door or window with a front main door open. That fan needs to stay on for about a half hour after blowing all off.

This Toxicity Table unfortunately does little to share the risks from the other chemicals that are frequently associated from woods and wood products that come from molds, fungi, yeasts, lichens, insecticides, herbicides, glues, resins, paints, solvents, binders, fillers, silicon, paints, plastics, etc. which are also known to be harmful to our health. For instance, wood molds create some of the most toxic poisons known to man, which is why so many turners get very ill when they turn spalted wood (wood with mold lines).
Disclaimer
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