I could be wrong, but the carbon filters are typically for volatile organic solvents, of which there are none in epoxy resin or hardener. Quite often I read of people using the carbon filters and I wonder if this is the correct choice. Certainly for sanding one is better served with a P100 filter. Without having more info I guess a person could choose a combination filter, but realistically I don't know what a person can protect themselves from when using any of the following common cartridges: organic vapour, acid gas, ammonia, mercury vapour, methylamine. Perhaps the carbon filters, although indicated for use with organic solvents, does offer protection against fumes that may be released from epoxy.

I'm waiting for access to a publication that looks like it might shed some light on this subject. Other than that, I believe epoxy is more of a health hazard in direct skin contact and sensitization.