At first I had difficulty making sense of the change in which the quaternary ammonium compound -based products were no longer recommended for porous surfaces. The revised USFWS document is not very helpful - there's a mention at the end regarding FIFRA (Federal Insecticide Fungicide and Rodenticide Act) definitions, but no context is provided to explain the rationale for the change.
Then I read the label and MSDS (Material Safety Data Sheet) for one of the products. The
Lysol IC Quaternary Disinfectant Cleaner label states:
Virucidal, fungicidal and bactericidal, this multi-purpose, hospital disinfectant cleans and disinfects hard, nonporous surfaces. The economical, concentrated formula makes up to 256 gallons (1:256). Use on floors, walls, glazed porcelain, plastic surfaces (such as polypropylene, polystyrene, etc.) and other hard, nonporous surfaces.
Takeaway: label use - "hard,nonporous surfaces."
And from the
Lysol IC MSDS:
It is a violation of Federal law to use this product in a manner inconsistent with its
labeling.
I suspect that the other commercial quaternary ammonium based products named in the USFWS document have similar labeling. Since their labels state that the use is for hard, nonporous surfaces, and since use inconsistent with the label is "a violation of Federal law" (presumably FIFRA), it seems fairly clear that USFWS should not be recommending their use on porous surfaces to kill a fungus (especially not one that's not even listed on the label - I wonder how long till someone notices that problem as well!)
That said, it's amazing that this is only just now coming to light, three years after the USFWS issued the initial WNS decontamination guidance document, given the labyrinth of review that these federal documents supposedly have to go through. It's also surprising that there isn't some form of waiver that USFWS could get, or supplemental product labeling that the manufacturers could get, since the efficacy of these products on porous surfaces against G.d. has actually been demonstrated.