The present invention is generally related to a device and method for sanitizing a medical instrument with ozone in particular the invention relates to a system method and a device for sanitizing a continuous positive airway pressure (CPAP) device. The device has an ozone compartment an ozone operating system and one or more ozone distribution lines that distribute ozone to a continuous positive airway pressure device. The device may further include a heater adapter unit to connect heating systems in CPAP devices while distributing ozone to sanitize the CPAP device in accordance with the present invention.