Based on what I've been reading on the subject the past few days, I actually I think it's best to say it this way..."Breathing carbon monoxide can kill you, and the N95 (or carbon masks) can help reduce the CO you're getting in your lungs". How does that sound?
Now remember, I'm not a chemist by any stretch, but I do know when my mask is turning black there's a reason behind it. Do I really care what that reason is? Not particularly (no pun intended). What is my primary concern? Stopping a deadly contaminant from entering my lungs.
Read the link below if you wish to learn more about this topic yourself. .
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7780759/