All woodworkers (carvers who don't use sandpaper excepted) produce wood dust. We must put up with dust in spite of the time, effort and expense of collecting and disposing of it. In this article I'll survey options for dealing with wood dust, the health issues related to exposure and what can be done to protect ourselves from harm.
In order of complexity and cost, measures for dust control include:
- a broom and dust pan – which actually adds to airborne dust
- a shop vacuum attached to individual machines by hand as needed
- a dust collector connected to a single machine by hand or, if you can afford it, to several machines through permanent ducts suspended from above or even embedded in the floor when you build the shop of your dreams
- as above plus the addition of an air filtration system
Dust particles are measured in microns. Dust collectors and air filters are most efficient in removing particles larger than 50-100 microns. The sheet of paper in your printer is 10 microns thick. Unfortunately, particles smaller than 2.5 microns are the greatest health risk because they can pass right through vacuum bags or filters into the room air and through your nose into your airways and lungs.
Dust collectors use a powerful fan to force large volumes of air and dust, into a bag. How efficient this is depends on how much air is moved (cubic feet per minute) and the percentage of dust that is held back (should be at least 95%). Check these ratings when you shop for a machine. If the performance of your machine is unsatisfactory replacing the original bag with a custom made one or a canister type filter will help; at less cost than buying a new collector. You will find several choices on the Internet.
A dust collector can also be upgraded by adding a second stage which is placed between the duct system and the collector. This consists of a container and a cyclone or turbo device which separates chips and larger particles before they reach the collector and increases the efficiency of collecting the smallest particles.
There is some debate about using air filtration systems. These are usually suspended from the ceiling and force large volumes of room air through a filter. But their best use is probably to clean the air in a workshop at the end of a work session rather than running continuously to remove dust while it is being produced. HEPA filters are most efficient at filtering out a high percentage of very small particles. Air filter specifications depend on the size of the room. The system should be able to filter the entire volume of air in a shop 6-8 times per hour. Before you select a system calculate the volume of your shop, multiply that by 6 or 8 and divide by 60. This gives a figure in cubic feet per minute to compare with the specs for the filter. Some sources advise placing the air filter near a wall to promote circular air flow.
There is little consensus on exactly how dangerous wood dust actually is. References I was able to find in the medical literature report various levels of risk. Here are some typical published studies on the health risks related to dust.
- Cancer Cancer of the nasal cavity and sinuses is the most well documented risk related to exposure to wood dust https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0133024
But the association with lung cancer is, at best, weak and probably limited to long term, occupational exposure.
No other forms of cancer have been found to be associated with wood dust.
Asthma A very comprehensive discussion of this problem has been prepared by the California Dept. of Public Health.
Pulmonary insufficiency This illness occurs primarily in association with long term occupational exposure.
Wood Dust in the eye First, you should have been wearing safety glasses. Do not rub your eye.
1. Wash your hands and look in the mirror and try to locate the sawdust particle. Blink several times and allow your eyes to tear up, the tears may wash the sawdust out. Dab the tears gently with a tissue.
2. Gently pull your lower lid away from the irritated eye while looking in the mirror. Search for the sawdust. The irritant may have moved into the corner of your eye. Repeat the process with your upper eyelid if you still haven't found the sawdust.
3. Allow your eye to rest for a moment and blink some more. Allow your eyes to tear up, then repeat Step 2. If you still feel the particle
4. Immerse the side of your face with the affected eye in a shallow container of water. While the eye is under water, open and close the eye several times. The same result can be accomplished using an eyecup from a drugstore.
5. If the dust is still present pull the upper lid away and stretch it over the lower lid to loosen the dust.
6. If the problem persists call your doctor or go to urgent care.
William Pentz, who sells high end central dust collection systems, is the most radical and controversial commentator on the risks associated with exposure to wood dust.
For some interesting discussion threads on the subject of safety and preferred methods of dust control, see:
Each of us must make his or her own choices about the level of risk and how far to go to protect yourself. But here are some practical tips to maximize the management of dust control in your own shop.
What about the bag that collects your dust? The American Fabric Filter Co, says, “a fine layer of dust coating the inside surface of the upper bag actually works with the fibers of the filter to trap small particles”. They advise that, if you notice a thick crust of dust inside the bag and decreased suction, before you toss the bag in the washer, try these steps: with the dust collector running and the bag inflated, tap the it with your hand or a broomstick. If that doesn’t clear up the thick crust, try blowing compressed air against the outside of the bag with the collector running. If that fails, remove the bag, turn it inside out and vacuum any remaining dust cake.
Check this company for information about custom dust bags.
Air filter systems vary considerably in quality and cost but all filters gradually become clogged and eventually need to be replaced. HEPA filters are expensive but generally agreed to be best. OSHA provides a good summary on the subject of dust collection and filtering.
Random orbit sanders are not only notorious for producing a lot of dust but they are also typically used right under our noses. The original equipment bags and filters provided are often inefficient. A down draft table can serve as a very effective way to reduce exposure to the dust created by a random orbit sander. You can shop for a wide variety of down draft tables for sale on the Internet or make one yourself. Rockler sells a nice kit for a 14″ X 17″ table for about $30.
None of these devices work if you fail to turn them on. Even if we remember to do so, inconvenience often leads us to skip this step. Several brands of a radio-frequency remote controller can serve as a very convenient, inexpensive way to turn machines on and off and save time as well as helping to preserve your health.
Depending on the species, direct contact with wood and dust can act as an irritant, causing nasal congestion, sneezing, eye burning, itching and rashes. Over time contact can also be sensitizing, leading to allergic reactions.
| Table 1: Health Effects Reported with Various Types of Woods (Adopted from Work Safe Alberta (2009)) |
|
| Wood Type | Health Effects |
| Alder (common, black, red) | Dermatitis (black alder); decrease in lung function (red alder) |
| Aspen | No health effect reported |
| Beech | Dermatitis (wood cutter’s disease) due to lichens growing on the bark of beech trees, rhinitis, asthma, nasal cancer |
| Birch | Irritant dermatitis |
| Cedar (western red) | Asthma, allergic contact dermatitis, sensitizer, decrease in lung function, eye irritation and conjunctivitis, rhinitis |
| Douglas Fir | Contact eczema, decrease in lung capacity |
| Fir (grand, balsam, silver, alpine) | Skin irritation, dermatitis, rhinitis, asthma, possible decrease in lung function |
| Hemlock | Skin irritation, decreased lung function |
| Larch (European, western) | Allergic dermatitis from European larch; no reports with western larch |
| Mahogany | Dermatitis, sensitizer |
| Maple | Rhinitis, asthma, Maple Bark Stripper’s disease (mould spores in bark) |
| Oak | Nasal cancer |
| Pine (white, lodgepole, jack) | Skin irritation, contact dermatitis, Wood-Pulp Worker’s disease (mould in bark), rhinitis, asthma |
| Poplar | Contact dermatitis, sensitizer |
| Rosewood | Eczema, allergic contact dermatitis |
| Spruce | Skin irritation, Wood-Pulp Worker’s disease (mould spores in bark), decrease in lung function |
| Teak | Toxic, dermatitis, sensitizer |
| Walnut (black) | Skin irritation, rhinitis, possible asthma |
| Yew | Irritation of skin, dermatitis, toxic |
Even the best air filter or dust collector can't completely clear the air of dust. But devices that catch dust before it reaches your nose and airways can help. They come in a wide variety of designs and expense, ranging from simple paper masks to a fully enclosed, power respirator. Paper masks are inexpensive but they are prone to leak. A good one should have two straps. The addition of some sort of seal around the edges of a mask adds more protection. An exhalation valve will your glasses from steaming up and sweating under the mask. Paper masks are rated according to their efficiency at filtering particles: N = 95%, C = 99%, R = 99.97%. A similar rating system used in the UK refers to FFP1 – FFP3 but also relates to aerosols and particles other than wood dust.
Better fitting, more elaborate masks which have replaceable filter cartridges, usually advertised as respirators, are more effective and can cost as little as $20. A silicone face seal will form an airtight barricade around your nose and mouth – unless you have facial hair which might require a full face hood. Here are three online reviews of dust masks and respirators.
Best – GVS SPR457 Eclipse Pro $32
Best for the money – 3M Rugged Comfort 6503 QL $20
1. 3M Rugged Quick Latch Half-face Respirator
2. Fightech Dust Mask
3. 3M Half Facepiece Respirator
4. GVS SPR457 Eclipse P100 Respirator
1. AMSTON N99 Disposable Dust Masks 10 pack $22
2. Safety Works 817664 Toxic Dust Respirator $30
3. GVS Eclipse Half-Mask Respirator $37
4. 3M Half Facepiece Respirator, medium $13.50
If your work requires long exposure to large amounts of dust, consider the ultimate in dust protection: a half or full face respirator with or without powered air flow. These devices range in price from $200 to $400 and up.
By Dick Ugoretz (originally published on September 2019)
Editor's Note: Light edits have been made to remove broken web links.