EnviroCon generates chlorine dioxide - a disinfectant/biocide that has been used industrially for probably 50+ years that I know of - commonly used for high-level disinfection for wastewater and water treatment plants and water treatment, hospital and food processing plant disinfection of inacessible areas and ducting and piping including disinfection against legionaires disease and anthrax for example.
And does not have the high respiratory hazard of chlorine gas or high levels of ozone - though can be adverse for people with respiratory sensitivty to chemicals, especially for the first few hours after application.
The issue of "safe for humans and pets" - the EPA's own website admits that the scientific data on its safety in direct breathing contact with people is indeterminate - so OSHA requires worker respiratory protection during use. Considering it destroys bacteria by breaking down the cell structure of basically any living organism - while it is considered safe for use in that it does not leave a significant residual after application and a good airing out (so is effective at time of application but does not prevent future contamination/regrowth), certainly one would be a fool to knowlingly stay in contact with air containing it.
Though it breaks down (quickly) in air, chlorine gas is one of the intermediate products until ozone and sunlight break it down further - so pets and occupants should be out of the house during treatment, but after ventilation of the house can reenter fairly soon - typically about an hour after treatment. Some applicators use it in ducting while a building is occupied - just plain dumb in my mind, and there have been cases of workers and building occupants being overcome by it when it was first considered harmless. Sort of a total brain freeze on that - you are using something that kills all living organisms it touches yet you consider it safe to use in occupied building ? Duhhhhh !
The fact the applicators wear respiratory protection should be your first indication that being in the house (including pets) while it is being treated is not too bright. Fish and amphibians (aquarium/terrarium) are also sensitive to it and can be killed. Typically aquariums/fishbowls that are too large to conveniently take out of the house can be sealed with saran wrap thickness plastic and aluminum foil sealed to the tank for the hour or two needed without harming the occupants.