The U.S. Department of Labor Occupational Safety & Health Administration (OSHA) has released proposed pandemic mask use and stockpiling guidance. It's a thorough report, CIDRAP has a good summary. I know that the mask issue has been discussed in dialysis pandemic planning circles; the recommendation is to use surgical masks (OSHA calls these facemasks) for the dialyzors and disposable N-95 masks (OSHA calls these respirators) for staff.
Which masks; how many
The Kidney Community Emergency Response (KCER) Coalition Pandemic Preparedness Team's website links to the Summary of OSHA Respirator Requirements (PDF link) which was the principal driver of the mask recommendation. The problem comes when you start to contemplate the quantities needed. Some dialysis providers have begun to stockpile N-95 disposable masks - 10, 20, 100 N-95s per employee. This is a significant expenditure but is it enough?
This latest document from OSHA offers additional guidance to dialysis units, suggesting that a stockpile for 120 workdays would be prudent. OSHA suggest that a nurse in an outpatient clinic might need four disposable N-95s per shift, meaning 480 to cover the whole pandemic. I've not heard of any dialysis provider stockpiling that quantity of N-95 respirators. That's hundreds of dollars of expense per employee. Not to mention the additional expense of fit testing the eventual wearer and storing them until they're needed. If you're going to make the investment, you should invest in the most robust alternative.
Disposable v. Reusable
And there is an alternative - reusable repirators that can be cleaned and repaired. The OSHA report list them as Elastomeric Respirators (flexible, rubber-like facepiece). They run $20 to $50 for the silicone half face plate and a couple sets of filters, and like the disposable N-95 respirators they must be fit tested and can't be used with facial hair (men should make sure razors are part of their pandemic prep). But unlike the disposable respirators these respirators can be worn day after day. In a dusty environment the filters would have to be frequently changed but in a dialysis unit the $3 filters would need to be changed much less frequently.
In dialysis provider circles there is resistance to going the reusable route (at least when I've brought it up at meetings) but I think that's short sighted. The OSHA proposed guidance lists "Harder to breathe through than a [N-95] facemask" as a mark against the reusable respirators but I am not sure that has to be the case. I've used disposable N-95 respirators when doing drywall and I've used the silicon half plate ones too - I can tell you that it is unpleasant to wear either one while working but the half plate reusable is less unpleasant. I think a high quality reusable half plate respirators makes much more sense financially and I think they're more comfortable.
What should be done
There is a way to resolve the question of which is the right respirator: side by side testing under actual conditions. The renal community needs to ask a dialysis unit(s) to operate using the various options. I seriously doubt the people making the stockpiling decisions have ever spent eight hours in either respirator but that would be instructive. One shortcoming that will be quickly identified during any testing is how any respirator or facemask acts as a barrier to communication. Testing during the operation of a dialysis unit would not only identify which respirator option makes the most sense, it would also identify practical problems that can then get addressed.
I'd bet a nickel that the reusables will test better.