High ozone shock treatment or ozone blasting is a process for removing unwanted odour, and killing mold, vermin and microorganisms in commercial and residential buildings. The treatment is less expensive than some alternative methods of sterilizing indoor spaces - cleaning or removal of building material, or in extreme cases the abandonment of sick buildings. Process High ozone shock treatment involves using an ozone generator with a timer to create lethal levels of ozone in an enclosed odour ridden or mold-affected room or building for a short period of time, between one and several hours. For safety reasons, the affected area must be evacuated of people, animals and live plants for the duration of the exposure, and for a long enough period afterwards to allow the ozone to dissipate. Results Exposure to high levels of ozone kills living organisms and weakens odours. By killing microorganisms and mold, ozone treatment slows ripening and reduces spoilage of stored fruit. Concerns Critics point to a 1997 study which found exposure to high levels of ozone ineffective at mold decontamination, and to the lack of studies showing high ozone shock treatment to be effective. They also point out that killing mold inside walls does not remove the mold, and that dead mold may continue to have adverse health effects on building inhabitants. There have since been many other studies confirming the effective use of ozone to kill mold in conjunction with other remediation techniques. Ozone is a powerful oxidizing agent which could damage rubber and other materials, and ozone reactions with other material present in buildings could lead to increased levels of noxious chemicals such as formaldehyde. References "Ozone and Mold", Jim Holland Building biology