Not all gas can be completely dissolved in water.  An off-gas system is built in every Biolux machine to decompose excess ozone back to oxygen before it is emitted.  So there's no worry of excessive ozone in the air even after continuous indoor prolonged use.  This safety design came from over 10 years of sanitation experience of Biolux's parent company; BES Group, to ensure product safety and effectiveness.  Biolux's ozonated water is an excellent sanitizer on every surface,  because it leaves absolutely no harmful residue,  it is especially good for direct food contact.