Personal Respirators for Woodturning and Sanding

by Lyn J. Mangiameli

There are basically two approaches to personal respiratory protection against dusts:

1. passive pressure devices (really lung powered)
2. powered positive pressure devices

Passive pressure devices are what most people think of and range from totally inadequate to quite effective at filtering fine dusts. Various cartridge masks (both full and half face), particularly from 3M, can be fitted with cartridges that meet NIOSH specs. I've heard mixed reviews as to the comfort of these masks and the likelihood of fogging, but they have the advantage that they also can be fitted with organic filters etc, for use with solvents and finishing materials. I have one for use with toxic vapors, but personally wouldn't want to wear it for an extended period of time at the lathe. My favorite NIOSH rated, MSHA approved non cartridge passive mask is the Dust Foe 88 (or the older Dust Foe 66 with the 88 filters). I've found it more comfortable in use than the 3M cartridge mask, and less prone to fog. Its filters are easy to replace and cheap. Packard Woodworks also sells a traditional surgical mask style (3M-8210) that is disposable, but is NIOSH rated. Airware America sells the 3 M-8210 and also the 3M-8511, which is slightly less expensive, but lacks the exhalation valve that reduces moisture build up within the 8210 mask. All of these are able to filter dust as well as the NIOSH rated powered respirators (i.e., better than the PowerVisor), but for some are more fatiguing to use for extended periods (it is your inhalations that are drawing the air through the filter), more difficult to seal well with beards or other facial hair, and more prone to facial discomfort on hot days.

Powered positive pressure devices run the gamut from self contained breathing apparatus (what the firemen wear), through remote ac powered air pumps with extensive filters (around $1200 and available from Woodworkers Supply), to battery powered helmets, to battery powered face shields. Traditionally, the three most popular units have been by 3M/Racal (3M bought Racal several years ago) and are the Airstream, the Airmate and the PowerVisor (which used to be called the Airlite). I have an Airstream and consider it the best of the bunch. It is a NIOSH/MSHA approved powered filtering unit with external hour battery pack. It now comes in two versions with either 8 or 10 cfm of airflow, depending on fan motor. I have the earlier AS200 version which works fine for me, though some have been able to achieve some moisture build up in theirs. The larger/faster fan version, the AS400 moves more air and thus is somewhat cooler and further reduces the possibility of moisture build up, but some have complained tha t the fan/motor noise is unpleasant and the battery life is reduced from 12 hours to 8-9 hours. The filter is the same for both units and is in the roof of the helmet. The helmet comes with molded face shield that can pivot up from the helmet, and has a shape and materials that are particularly resistant to breakage. This is the unit that Richard Raffan has used for a long time.

The Airmate 3 is similar but has the filter and 8 hour battery combined into one unit on a waist belt, then runs the air to the helmet with a hose. The Airmate 3 has a flat face shield that gives somewhat better peripheral vision than the Airstream, but less impact resistance (though still pretty adequate). A couple of years ago, 3M stopped making the helmeted version of the Airmate, offering it only with a Tyvek cowl. Airware America offers a hybrid version, using an Airstream Helmet fitted to the Airmate belt mounted filter and battery.

The PowerVisor is the least expensive of the 3M/Racal units. It has a flat shield more like the Airmate, but has both battery and filter located above the visor. The battery is rated for four hours, and the filter IS NOT NIOSH RATED. Peter Hemsley's Toolpost used to offer a hot-rodded version of the PowerVisor called the SuperAirlite, that came with an 8 hour external battery pack (but note the charger is set up for 220 volt). Peter may still be able to upgrade an existing unit.

In the latest catalogs from Packard, Craft Supplies, and Airware America, an Airmate like devise has appeared, called the Airmaster 30 and a PowerVisor like device called the Airmaster 20. These are made by a different company, CAPA, and come with a 4 hour NiMH battery and a belt mounted blower that offers 8 CFM of air flow. They are NOT LISTED AS A NIOSH RATED respirator. Both have impact resistant visors that pivot, and include a face seal.

All the positive pressure devices provide eye protection as well as respiratory protection. Not only against flying objects, but against dusts and mists. This, in my opinion, is a big plus. All have available visor overlays, which both make it easier to keep the visor clean, and indefinitely extend its life. All positive pressure devises are comfortable to wear with either glasses or contacts (indeed, I am never more comfortable in my contacts than when I'm in my Airstream or PowerVisor). All provide a cooling effect that greatly reduces fogging and provides comfort on hot days. It is possible with all models to fog them up slightly when involved in extended exertion (say strenuous chainsawing on a 100 degree day), but this will clear up quickly as soon as the exertion level is reduced. Because they create a positive pressure within the shield, they don't have to fit as tightly as the passive respirators, yet still completely prevent the entry of dusts into the unit. I have not found the helmeted versions to be any hotter than the open visor versions, and if anything, the Airstream helmet is better balanced and fits more comfortably than the PowerVisor (I haven't compared the CAPA units). The PowerVisor can be used with traditional over the head ear protection (just as can the passive devices). The Airstream helmet (I don't know about the Airmate or CAPA 30) requires a special behind the head band style of ear protection, though Peltor makes a excellent muff in this configuration (H10B with 28 db rating). As mentioned earlier, there have been some complaints about the noise from the Airstream 400, I find the Airstream 200 and PowerVisor fans to produce a significant but very acceptable amount of noise, I don't know about the belt mounted fan of the Airmate or CAPA units, but would expect their noise to be minimal, and of course the passive filters make no noise at all.

Recommendations

I regularly use both the PowerVisor and the Airstream. I find the PowerVisor to be very easy to take on and off quickly, to have great peripheral vision, and to be nice in that there are no cords, air tubes, remote battery packs, or hip belts to contend with. It works well for chainsaw, table saw, router work and lathe turning, but it does not have a filter up to removing fine sanding dusts (though you can, just barely, fit a DustFoe, or more easily one of the 3M 8210 NIOSH rated surgical style masks underneath the PowerVisor to pick up the fine stuff). For sanding on the lathe or with any other sanding situation, and finer cuts on the bandsaw, I always use the Airstream. If I fine sand blackwood acacia with the PowerVisor, I get a head ache and nasal irritation; if I religiously wear my Airstream instead, I'm totally unaffected. I strongly recommend getting a second battery pack if you purchase a PowerVisor or the CAPA Airmaters. Four hours is often not enough, particularly if you try to let your batteries run down before charging. The ability to pop in another battery while the first is charging is great help. For a very reasonable fee, Dave Reel (http://members.cox.net/dreel/index.php ) will rebuild a PowerVisor battery and increase its capacity to 10 hours. Most will find all of this is to be not much of an issue with the 8-12 hour battery that comes with the Airstream and Airmate.

So, I'd recommend the Airstream or Airstream/Airmate hybrid if you can afford it. You'll almost surely notice a big improvement in your health and comfort. If you can't swing the Airstream, go with the PowerVisor, but BACK IT UP with a NIOSH rated passive mask for sanding. Unfortunately there are reports that the PowerVisor may be discontinued, at least in England (Peter Hemsley of the Tool Post says they have been discontinued). I haven't confirmed these reports, nor know if they apply to the US. It may be that there will be a replacement unit in the works, or perhaps they are being discontinued on a regional basis because of differing safety laws, but I have yet to see a definitive statement on this. Having not used either of the CAPA units, I can't offer any judgment based on experience, but it is hard for me to see how they represent a good value at their near 500 dollar price, when having only a 4 hour battery and lacking NIOSH rating.