Unlike some other CPAP cleaning devices, the Lumin does not utilize the disinfecting properties of Ozone. Some people have reported that Ozone (also known as activated oxygen or O¬3) can leave a sharp or unpleasant smell. While this smell can be alarming or off-putting, it is not dangerous or harmful in any manner. Other CPAP cleaners, like the Lumin, use Ultraviolet light which has similar germicidal properties to activated oxygen; however, it is only light or energy and therefore has no smell to it. The only odors associated with the Lumin are the smells of the new plastic of which the device is made. Therefore, if you find the scent of O3 too strong, you may want to check out the supply of different Lumin CPAP cleaning devices on bestcpapcleaner.com. Our friendly customer service team would be glad to discuss the Lumin, the Lumin Bullet, and its UV cleaning power with you further.