Flu masks & co2

[Rexie]

The hospital where I work requires us to wear a mask if we do not receive a flu vaccine, no matter the reason. One of the respiratory therapists told me that certain masks will cause a build up of co2. Has anyone else heard this?

[Double-Helix, BSN, RN]

I suspect any barrier around your mouth and nose that is durable enough to stop droplets from getting in would restrict airflow enough to cause a slight increase in CO2 after awhile. Similar to breathing into a paper bag with a few holes in it. I highly doubt, however, it will be significant enough that an otherwise healthy adult (who should be changing the mask in between each patient) would be affected.