****!!!!****!!!!**** {510(k) exemptions for COVID.} "FDA considers chemical/physical disinfectant devices to encompass chemical disinfectant solutions used to disinfect medical devices." "Medical devices disinfectors... exempt from premarket review." "during the declared public health emergency, FDA does not intend to object to the distribution and use of sterilizers, disinfectant devices, and air purifiers that are intended to be effective at killing the SARS-CoV-2 virus but do not already have FDA marketing authorization, without compliance with the following regulatory requirements where such devices do not create an undue risk in light of the public health emergency: prior submission of a premarket notification under section 510(k) [and some other requirements]. FDA believes such devices will not create such an undue risk where the performance and labeling elements... are met." "If the device generates ozone, FDA recommends that the manufacturer evaluate whether the product is within the maximum acceptable level of ozone given in 21 CFR 801.415." [****It sounds like chlorine dioxide could be used if stays below regulated air levels. FDA has endorsed ClO2 standards for air related to food processing [ but need to check FDA's approved air concentrations for around people]. EPA has approved safety of air concentrations at specific levels around people.****]