N95 Mask and Portcount Machine

[Trauma08]

Hello,

I did a search regarding the N95 mask but I couldn't find anything regarding the portacount machine. I was fit for a n95 mask when I started my job about 2 months ago and passed the taste test. Than I actually needed to wear it for a patient and I couldn't get a good seal - my glasses kept steaming up. So I scheduled a repeat test. My employee health nurse put me on a portacount machine that somehow measures whether or not particles are getting into the mask. She switched me from the KC n95 regular to the 3M green mask for the test on the portacount. I had the same problem with the steaming glasses but I passed the portacount test. She said that my steaming glasses didn't matter because I passed the portacount test. I know that the masks only protect for 95% of particles but does anyone have any information regarding the portacount machine and its accuracy? I just want to be sure that I'm not being exposed to TB. I work in an area of the hospital with a lot of TB patients.

Thanks.

[Trauma08]

Oops. I meant Portacount in the title not Portcount. Anyway, hope to get some replies. Thanks.

[3rdcareerRN]

First, look at this presentation for an overview of fit testing:

http://www.cdc.gov/niosh/npptl/resources/pressrel/announcements/113004wkshp/pdfs/Presentation%2012_Roy%20McKay.pdf

For specifications on the Portacount, see:

http://www.tsi.com/Category.aspx?Cid=24

The Portacount measures the particles inside the mask compared to outside, and it is quite accurate. TSI can supply research citations if you're still in doubt.

The issue is not with the Portacount accuracy, it is with your respirator fit on the job. What the Portacount measures is particles that have leaked around the mask, plus the 5% of the particles not filtered. If you put on the mask differently on the job than for the test, you have a risk of particles (ie. TB in your case) entering between the mask and your face. OSHA requires this test annually, partially because your face can change over a year (muscle gain/loss, fat gain/loss, dental chg.).

Steam on glasses are from exhaled vapor. The presence of vapor alone does not verify a fit.

If you are really worried, (a) don't take that assignment or (b) get powered air purifying respirators into your workplace, so that you don't have to do fit tests.

(Yes, I've been through the NIOSH training for testing occupational respiratory protection. No, I have no connection with TSI or other vendor.)

[Trauma08]

Thanks 3rd career,

The second of the two links I did find yesterday when hunting around on the internet for the answer. I totally get that the steam is just water vapor that I exhale. I guess I wonder if the vapor is going through the mask or around the mask. It seems like it would have to be going around the mask and if so wouldn't it be possible for other particles to travel through the same space? When I inhale of course. I don't know why I'm so paranoid about it. We do see a lot of patients with active TB plus my employee health nurse seemed a bit cavalier about the whole thing, I just needed some reassurance.

Thanks again!