Hi Ralph,
Is that breathing directly into a CO2 meter, or analyzing the air in the breathing zone under a mask? The air we breathe in contains about 0.04% CO2, but we exhale air that contains about 4 to 5% CO2.
Thanks,
Bruce
_____________________________________
Bruce Backus
Assistant Vice Chancellor | Environmental Health and Safety | Washington University in St. Louis
4533 Clayton Ave.| Campus Box 8229 | Saint Louis, MO 63110
S: 314.362.8976 | Cell C: 314.302.0466 | : backusb**At_Symbol_Here**wustl.edu
-----Original Message----- > 900 to 1000 ppm CO2 is also where documented effects on mental acuity can be shown. It's a nice number. Is there a reference for this? I just had one of our librarians who had been wearing a cloth mask for an hour exhale into a CO2 meter and he hit 3500 ppm. After wearing a cloth mask for 20 minutes, I max out around 1500, so I suspect that the longer wearing periods could become productivty problem. - Ralph Ralph Stuart, CIH, CCHO ralph.stuart**At_Symbol_Here**keene.edu --- ---
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