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Originally posted by LesBrooks:
Only one more stock that I started several years ago and it will be my last. Time to stop..

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DUST AND THE WOODWORKER
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In 15 minutes of use, this disc sander filled a shop's atmosphere with a cup of powdery dust, the size that can negotiate your lung's smallest airways. The Occupational Safety and Health Administration (OSHA) recommends that your short-term exposure limit (STEL) be less than one rounded teaspoon of dust in a 24-ft. by 24-ft. shop in 15 minutes. OSHA's permissible exposure limit (PEI) for an eight hour shift is about one-half of a teaspoon of dust suspended continuously in the same shop's atmosphere.

What serious woodworker doesn't know the pleasure of wiping a delicate film of very fine dust off a well-waxed jointer bed? I like reaching into a tablesaw base and spilling out arm loads of wood dust onto my knees and the surrounding floor. In fact, I don't mind dust in my hair, in my beard and in my pockets. And I've not only come to love the feel and sight of wood dust, but the satisfying aroma as well. I was first tempted to start woodworking when my best friend built a cedar porch swing for me-the air in his shop was filled with the rich scent of the wood. Since then, I've built my own shop and filled the air with dust from a dozen different woods, including sassafras, walnut, redwood, mahogany, teak, cherry, maple, oak and poplar.

Yes, the woodworker in me enjoys wood dust, but the doctor in me is suspicious because the dust so often irritates my eyes and lungs. My concerns led me to the hospital library to research woodworking's effects on the respiratory system. What I found was both surprising and a little disconcerting. A computer search of medical literature revealed more than 250 articles pertaining to the hazards of woodworking. The articles covered a wide range of problems, including traumatic injuries, skin disorders and cancer associations, but most dealt with how wood dust inhalation affects the lungs.

How much dust is harmful? - Wood comes off tools in many different shapes and sizes, including broad, flat shavings; long, thin splinters; small chips; and coarse and fine powdery dust, such as that produced by the disc sander shown above. Hand-sanding produces fine dust. But power sanders, the big guns in the sanding arsenal, are the tools most responsible for creating lingering dust clouds in the shop. Powdery dust consists of the smallest particles and represents the greatest health hazard to the lungs. This fine powdery dust not only floats in the air for a long time, but it can be inhaled very deeply.

Dust particles can be classified into two groups: those smaller than 10 microns in diameter and those larger than 10 microns (one micron equals one millionth of a meter). The smaller particles are respirable: they are little enough to negotiate the tiny airways that reach deep into the lungs. Particles bigger than 10 microns tend to get trapped in the larger airways.

Wood dust, as inviting as it may be, is no friend to the woodworker. Given the fact that most of us are not going to sacrifice woodworking to save our respiratory system, the question arises: How much wood dust is too much? Two variables that must be considered are the amount of dust you breathe and how long you breathe it. If you spend just a few hours per week in the shop or if you work mainly on small projects that do not demand much sawing and sanding, you probably do not have to worry about bronchitis, pneumonia or nose cancer. If, however, you spend long hours on big projects that require extensive ripping and sanding, you should be cautious, especially in light of the small amount of dust that researchers and government regulators say is the threshold limit for ambient dust (beyond which lung disease begins to develop).

According to a 1981 report published by the American Conference of Governmental Industrial Hygienists, the maximum level of airborne respirable particles should average no more than five milligrams of dust per cubic meter of shop space in eight hours. Other studies suggest that this level is too high and recommend a maximum of two milligrams of dust per cubic meter. These studies propose that more than two milligrams of wood dust per cubic meter of shop space may damage your lungs.

What do these limits mean to you? Let's suppose your shop is 27 ft. long by 21 ft. wide and the ceiling is 9 ft. high, so it is roughly 170 cubic meters According to the stricter guideline of two milligrams of dust per cubic meter, you should limit airborne dust to less than 340 milligrams. This is one-third of a gram, which I discovered equals slightly less than one-quarter of a teaspoon of dust. A full sandwich bag weighs almost 50 grams, which is enough to exceed the threshold limit of a 25,000-cubic-meter shop. This is all very disconcerting and even the authors of the cited study conceded that, though ideal, this strict (two milligram per cubic meter) standard is not very realistic.

A Guide to your Respiratory System - Dust's affect on your lungs, however, is realistic, but you must first understand your respiratory system so that you realize just how injurious dust can be. The lungs are extraordinary, organs that continually bring fresh air into very close contact with your body's circulatory system. Structurally, the lungs are like sponges with millions of tiny air pockets. Their ultimate purpose is to remove carbon dioxide from the blood stream and replace it with fresh oxygen from the atmosphere. This process is called gas exchange. The air pockets are called alveoli, shown in the drawing on the facing page, and gas exchange takes place within them. When you breathe in, the alveoli fill with air and oxygen passes through their ultra-thin walls and into the surrounding blood. At the same time, carbon dioxide from the blood passes into the alveoli, where it is expelled during exhalation.

The flow of air in the lungs takes place through a set of airways that spread out very much like the branches of a tree, as shown in the drawing. The tree trunk corresponds to the trachea, the first large branches are the bronchi and the smaller branches are the bronchioles. In this analogy, the alveoli are like the leaves of the tree.

In addition to moving air in and out of the body, the lungs must keep themselves and the air clean, warm and moist This job is accomplished by the "mucocilliary transport" system, a term for the mucus-producing tissue that lines the "bronchial tree" (see the drawing). \Ve are all familiar with mucus, though we may not be familiar with its purpose. Not only does it serve to moisten the air, it also protects the underlying tissue from drying out. In addition, it acts like flypaper to catch the microscopic dust and dirt in the air we breathe. Once these dust particles are trapped, they must be discarded. This is done by the other part of the mucocilliary transport system, the ciliated epithelial cells. These cells have hundreds of tiny little arms that literally sweep the dust-laden mucus up and out of the lungs. In addition, a backup mechanism, the "alveolar macrophage," serves to clean out dust that gets into the alveoli. This system consists of cells that wander around in the alveoli like little street cleaners, sweeping up particles that threaten to interfere with the crucial gas-exchange system.

How Does Dust Harm These Organs? - In the healthy person, occasional dust particles in the lungs is not a serious problem because the lungs have built-in defense mechanisms, such as the mucus that lines the airways, that halt harmful substances like dust. The dust-laden mucus is then expelled from the lungs by the sweeping-motion cells lining the airways, as well as by coughing. Unfortunately, however, chronic inhalation of wood dust may damage the lungs' cleaning systems. When this happens, a vicious circle begins as more dust collects and further damages the lungs. The body then responds as it does to skin injury-it mobilizes an inflammatory response. That is, the bronchial airways become red, swollen and painful. Swelling decreases the diameter of the airways and produces shortness of breath, induces coughing and increases sputum, which is saliva and other discharged matter from the respiratory passages. A number of studies have shown that these symptoms are common in active woodworkers: those that spend long hours in the shop. Other studies have shown that woodworkers tend to develop lung problems similar to those found in patients with chronic bronchitis and emphysema-diseases associated primarily with cigarette smoking. Inhaling wood dust, while probably not as harmful as smoking, can be dangerous.

Perhaps the most documented effect of wood-dust exposure is nose cancer. Dozens of studies in more than 10 countries have shown an increased rate of this relatively rare form of cancer among woodworkers. Medically it is known as "nasal adenocarcinoma." Mucus-secreting glands in the noses of woodworkers tend to become cancerous at a rate 1,000 times greater than non-woodworkers, apparently because of the dust. Fortunately, this type of cancer is relatively rare even among woodworkers (only about one in 1500 active woodworkers will ever develop it), and the time-lag between exposure and the onset of symptoms is as much as 40 years.

Finally, wood dust can cause respiratory illness because it contains many types of allergens and toxins. These range from chemicals deposited on the tree from the outside, such as pesticides and fungal spores, to chemicals created by the trees themselves, such as alkaloids, saponins, aldehydes, quinones, flavonoids, steroids and resins. Individuals respond differently to these various toxins, bur the symptoms are universal: coughing, sneezing, increased phlegm and sputum production, runny nose, red eves and, in extreme conditions. bronchitis, pneumonitis, and asthma. These symptoms are found in woodworkers more often than in the general population.

You are probably more familiar with some toxins and allergens than with others. Perhaps woodworkers are most aware of the allergen called plicatic acid, a substance in red cedar that is responsible for a condition known as red-cedar asthma. This very debilitating condition occurs in about 5% of people who work with red cedar. Another similar condition is maple-bark disease, a severe form of asthma probably caused by fungal spores found in maple bark. Two other North American woods considered to have significant allergenic effects are boxwood and sequoia redwood.

Clearly, the concern about dust is not just academic and all of us woodworkers must be aware of these insidious problems. Most of us don't hesitate to use goggles, push sticks and blade guards, but how many of us use face masks and dust collectors regularly? Not many, I'm afraid. Dust masks can be uncomfortable and dust collectors are expensive, but both are well worth the investment. As with many other items I've bought for my shop, I've agonized over spending money on a dust-collection system, but I'll probably wonder how I ever got by without it once I use it.

Kirk Kundtz is a resident physician in internal medicine at Mount Sinai Hospital in Cleveland, Ohio, and is an active woodworker. Thanks to Drs. Lawrence Martin and James Edmonson for assistance in preparing this article.

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gasgunner: Myabe you need to use vacume rather than air pressure

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Originally posted by Rsm458Lott:
I own my own contracting buisness and had a project a few months ago that used a lot mahogany.The dust that wood makes is the most toxic of any I've ever seen in 20 years of working with wood.

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Originally posted by Rsm458Lott:
My statement is from the way it burned your eyes and breathing passages if any got through the mask.I have'nt worked with a lot of the African exotic woods so I can't say with them.But among what I've worked with the dust seemed very acidic.Just my opinion.

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tox·in (tksn)
n.
A poisonous substance, especially a protein, that is produced by living cells or organisms and is capable of causing disease when introduced into the body tissues but is often also capable of inducing neutralizing antibodies or antitoxins.

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Allergen
An allergen is any substance (antigen), most often eaten or inhaled, that is recognized by the immune system and causes an allergic reaction.
No comprehensive list of allergens is currently possible. Sensitivities vary from one person to another and it is possible to be allergic to an extraordinary range of substances.

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ir·ri·tant (ĭr'ĭ-tənt) Pronunciation Key
adj. Causing irritation, especially physical irritation.

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sensitizer, n.sen·si·tiz·er
To make hypersensitive or reactive to an antigen, such as pollen, especially by a second or repeated exposure.

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reaction categories
Eye and skin irritation (hives, itching, redness).
Respiratory problems.
Nausea, headache, or general malaise, possibly even liver or kidney malfunction.
Cancer of nose and sinus. Statistics show that woodworkers have a 40 per cent greater chance of nasal cancer than the general population

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Originally posted by jeffeosso:
this is in good humor, but I wish to point out that nitpicking words often leads to spralling discussions and/or arguments, just because people generally always act in the manner they believe correct, and frequently don't like to be corrected.

So, since the words toxic, irratant, Allergen and sensitizer can be used more or less interchangablely in this context.

and, frankly, it's terms of jargon, with the person's assumptions of the genre leading to their words choice.

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tox·in (tksn)
n.
A poisonous substance, especially a protein, that is produced by living cells or organisms and is capable of causing disease when introduced into the body tissues but is often also capable of inducing neutralizing antibodies or antitoxins.

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Allergen
An allergen is any substance (antigen), most often eaten or inhaled, that is recognized by the immune system and causes an allergic reaction.
No comprehensive list of allergens is currently possible. Sensitivities vary from one person to another and it is possible to be allergic to an extraordinary range of substances.

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ir·ri·tant (ĭr'ĭ-tənt) Pronunciation Key
adj. Causing irritation, especially physical irritation.

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sensitizer, n.sen·si·tiz·er
To make hypersensitive or reactive to an antigen, such as pollen, especially by a second or repeated exposure.

However,
wood "called" Toxic, with irritants or sensitizers. here's a general link, but look up wood and toxic on google
http://www.mimf.com/archives/toxic.htm

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reaction categories
Eye and skin irritation (hives, itching, redness).
Respiratory problems.
Nausea, headache, or general malaise, possibly even liver or kidney malfunction.
Cancer of nose and sinus. Statistics show that woodworkers have a 40 per cent greater chance of nasal cancer than the general population

the reaction one is concerned with, of course, is the "hyper sensitivity reaction", which can only grow over time, and leads to increasing reactions by the body... BUT, unlike a cold, an upper resp infection, or hayfever, the hyper sensitive reaction leads to worse and worse immune system reactions, up to the point of alergic shock... or what happens when persons have the so called "bee sting" alergies... this alergic reaction can become so strong it leads to death for the sufferer...

but it's still a toxin, an irritant, a sensitizer, and an alergen. ...

weird huh?

jeffe

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Originally posted by Customstox:
So in keeping with only posting on gunsmithing issues and germane to the forum at hand, will you refrain from posting???