Fumigation of herbal material


I’d like to know your opinion about EU GMP Guidelines, Annex 7 “Manufacture of Herbal Medicinal Products”. The table illustrating the application of Good Practices to the manufacture of herbal medicinal products defines purification of herbal substances as a GMP area.

My question is: what is the proper approach to the process of the herbal material CO2 fumigation? Should it be concerned as the purification, and, therefore, should it be a subject of DQ/IQ/OQ/PQ?

(Fumigation is only used for killing the pests, than the herbal material is being sorted, physically purified and decontaminized in autoclave).