On Sep 16, 2020, at 8:54 PM, ILPI Support <info**At_Symbol_Here**ILPI.COM> wrote:

Nothing authoritative here, just logic and common chemical sense:

Odors are the individual molecules that reach your odor receptors (think about that next time you're cleaning the cat box!). Gaseous single molecules (vapors) are orders of magnitude too small to filter with fabric and will be unaffected by even an N100 face covering except perhaps for a de minimus amount of physisorption.

Aerosols containing odorants will be blocked by a properly fitted face mask because those particles are larger than the pores in the fabric. For example, you shouldn't smell Febreze or air freshener if someone sprays that while you're wearing a mask, at least initially until the aerosol carrier evaporates.

This is the whole basis by which masks prevent the transmission of SARS2 - while the virus particles are smaller than 0.3 microns, the aerosol particles they are riding on are approximately that size or larger and are greatly reduced or stopped by a properly fitted N95/N99/N100 mask.

As the researchers are in a lab and are more likely working with chemical vapors rather than aerosols, I would strongly doubt that simple masks pose any safety hazard with respect to odor detection.  I'm sure John Callen, who worked for 3M's Personal Safety Division and is the DCHAS resident guru on such, can add some insight here.

Of course, if we are talking about a mask with a charcoal or chemical absorbing cartridge or layer, then that's a different matter.

Rob Toreki

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On Sep 16, 2020, at 7:55 PM, Kim Jeskie <jeskiekb**At_Symbol_Here**COMCAST.NET> wrote:

Just a curiosity question.  We have a research group raising concerns that face coverings could inhibit one's ability to smell, a sense they believe they really need to have in a laboratory setting. I've seen publications disputing concerns around carbon dioxide entrapment and heard plenty of practical comments about being able to smell cologne through the coverings, but I haven't seen anything published on this topic.  It sounds like a weak argument to me, but I don't want to simply discount this concern without a good faith effort to find out if there's any real evidence that this is a valid concern. Any thoughts/comments that you would care to share?

Thanks,
Kim

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