Rust - Tools #1 Enemy
- All about Respirators and Dust Masks
Depending on the woods you've worked with (and how long you've been in the shop), these problems could have ranged from a little sneezing now and then - to flu or pneumonia-like symptoms, headaches or conjunctivitis that resulted in a need for serious medical attention.
Of the domestics, walnut, Western red cedar, chestnut,
oak, redwood, hemlock, birch, sassafras and willow are among the most
common. In addition, exotics such as cocobolo, ebony, satinwood, rosewoods,
wenge and mahogany are also known to cause respiratory distress. However,
extended exposure to virtually ANY wood dust will eventually lead
First, capture as much of the dust as possible at its source by using adequate dust collection. Shopsmith's DC-3300 Dust Collector can be attached to virtually every tool set-up and will go a long way toward eliminating most of the dust you create before it becomes airborne.
Next, never work in an enclosed shop without adequate ventilation. Open some windows. Install powerful window fans to carry away airborne dust. Clean up after yourself to eliminate coatings of dust that can accumulate and be re-circulated again and again.
And finally...AND MOST IMPORTANTLY...ALWAYS
wear a dust mask or respirator. Yes, it's going to be more uncomfortable
than working without one. Yes, it's easy to forget. Yes, you're going
to think...“It's just a couple of cuts...and probably won't
make any difference.” In short, you're bound to come up with
reason-after-reason why wearing a respirator or mask isn't necessary...but
you know what? IT'S ALWAYS NECESSARY! ALWAYS!
OSHA regulations offer some guidelines
For the average home woodworker, air-purifying respirators are the most logical solution...both from the standpoint of effectiveness and cost, since atmosphere-supplying respirators are extremely costly and therefore far more appropriate for commercial applications where workers are continuously exposed to high concentrations of contaminants.
Types of contaminants
The first are particulate contaminants. These are measured in microns with 1 micron equaling 1/25,400 of an inch...pretty small by anyone's standards. Particulates below 10 microns are the most likely to enter the respiratory system...and those below 5 microns are the most likely to reach the deep lungs, where they can do the most damage. In healthy lungs, 5 to 10 micron particles are usually removed from the upper respiratory system by a constant cleansing action. Smaller particulates are not.
It's also important to note that excessive exposure to even the larger-sized particulates can significantly reduce the efficiency of this cleansing action. Woodworkers should be most concerned by 1/2 to 10 micron particles that are most frequently filtered out by “fibrous” filters.
Secondly, vapor and mist particles (measuring five
to 100 microns) that are created by fumes and the spraying of toxic
finishes should also be a concern for the home woodworker. Organic
vapors and sprays such as solvents, glues, thinners and finishes can
create a serious hazard in the home shop. These are most often eliminated
through the use of a chemical or charcoal-filled cartridge.
Respirator types and styles
Among these two types, there are three styles to choose from:
These “atmosphere-supplying” types can be battery powered or powered by 110-Volt current. They provide the most effective protection (especially if you have a beard or wear glasses) and are easier to breathe through than non-powered models. However, there is a hefty price to pay for this comfort and convenience....typically in the $150 to $400 or $500 range with replacement filters that range from $10 to $22 a pair or more. Non-Powered, full-face respirators range from about $100 to $200 with cartridges that average $12 to $20 per pair.
All of the better quality masks are made of silicon
or rubber and seal much more effectively. Some even include soft,
fabric seals for additional comfort. It's best to go with a rubber
or silicon-type mask.
So, if you're working in an enclosed area with a high concentration of fumes from these substances, be sure to provide adequate ventilation. If you're working with lacquers, it's important that you use a respirator with charcoal filters designed to trap these vapors.
If your respirator is doing its job, you shouldn't smell even a hint of these vapors when wearing it. If you do, it's time to replace the cartridges. And once again, most filter cartridges are designed primarily for vapors and mists and will typically not effectively remove dust particles without the use of a fibrous pre-filter.What about cleaning mask filters to extend their lives? This practice is discouraged as it destroys the effectiveness of the filter medium and will render your mask virtually useless.