**** "ClO2 struggled to be accepted initially as a fumigant because of fears over its potential corrosiveness and toxicity. It is ***not considered a substance of concern by the ECHA, so is exempt from BPR PT2***. ClO2 fumigations are actually not corrosive, but a controlled study by the US EPA showed it can be corrosive inside functioning computers due to the heat from the CPU" "study gives this system the thumbs up in terms of its efficacy and reliability in comparison with formaldehyde against a range of tough-to-kill pathogens and spores. It is also excellent at inactivating beta-lactams" [Note: Fogging of chlorine dioxide liquid solution likely results in greater concentrations in some areas of room for at least some of the time. How much might variations in humidity throughout a room result in variations in chlorine dioxide concentrations in different areas when chlorine dioxide gas is emitted separately from any liquid?): "The other main advantages of this [hydrogen peroxide/ peracetic acid] system are that the room humidity does not need to be raised pre-fumigation, so there is little chance of the chemical pooling in cooler areas."