Why CO protecton?
I'm not sure you can filter CO. You need scba in an environment with high CO levels. FD's combat high CO levels by ventilating the area.
Smoke contains all kinds of hazardous chemicals, any number of which can incapacitate you and prevent you from escaping a fire. However, carbon monoxide (CO) is both a potent gas and also not easily filtered like other chemicals, therefore if you want protection from CO, you need to specifically look for that capability in the products you choose.
There doesn't need to be an extremely high level of CO to cause you problems since it binds tightly to your hemoglobin and its effect quickly builds up.
There are any number of smoke hoods marketed to civilians that can protect against CO. We were just discussing smoke hoods the other day in Sue's thread
here.